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1 | =head1 NAME |
2 | ||
3 | perlport - Writing portable Perl | |
4 | ||
e41182b5 GS |
5 | =head1 DESCRIPTION |
6 | ||
b7df3edc GS |
7 | Perl runs on numerous operating systems. While most of them share |
8 | much in common, they also have their own unique features. | |
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9 | |
10 | This document is meant to help you to find out what constitutes portable | |
b7df3edc | 11 | Perl code. That way once you make a decision to write portably, |
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12 | you know where the lines are drawn, and you can stay within them. |
13 | ||
b7df3edc GS |
14 | There is a tradeoff between taking full advantage of one particular |
15 | type of computer and taking advantage of a full range of them. | |
16 | Naturally, as you broaden your range and become more diverse, the | |
17 | common factors drop, and you are left with an increasingly smaller | |
18 | area of common ground in which you can operate to accomplish a | |
19 | particular task. Thus, when you begin attacking a problem, it is | |
20 | important to consider under which part of the tradeoff curve you | |
21 | want to operate. Specifically, you must decide whether it is | |
22 | important that the task that you are coding have the full generality | |
23 | of being portable, or whether to just get the job done right now. | |
24 | This is the hardest choice to be made. The rest is easy, because | |
25 | Perl provides many choices, whichever way you want to approach your | |
0a47030a GS |
26 | problem. |
27 | ||
28 | Looking at it another way, writing portable code is usually about | |
b7df3edc GS |
29 | willfully limiting your available choices. Naturally, it takes |
30 | discipline and sacrifice to do that. The product of portability | |
31 | and convenience may be a constant. You have been warned. | |
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32 | |
33 | Be aware of two important points: | |
34 | ||
35 | =over 4 | |
36 | ||
37 | =item Not all Perl programs have to be portable | |
38 | ||
b7df3edc | 39 | There is no reason you should not use Perl as a language to glue Unix |
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40 | tools together, or to prototype a Macintosh application, or to manage the |
41 | Windows registry. If it makes no sense to aim for portability for one | |
42 | reason or another in a given program, then don't bother. | |
43 | ||
b7df3edc | 44 | =item Nearly all of Perl already I<is> portable |
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45 | |
46 | Don't be fooled into thinking that it is hard to create portable Perl | |
47 | code. It isn't. Perl tries its level-best to bridge the gaps between | |
48 | what's available on different platforms, and all the means available to | |
49 | use those features. Thus almost all Perl code runs on any machine | |
6ab3f9cb | 50 | without modification. But there are some significant issues in |
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51 | writing portable code, and this document is entirely about those issues. |
52 | ||
53 | =back | |
54 | ||
b7df3edc GS |
55 | Here's the general rule: When you approach a task commonly done |
56 | using a whole range of platforms, think about writing portable | |
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57 | code. That way, you don't sacrifice much by way of the implementation |
58 | choices you can avail yourself of, and at the same time you can give | |
59 | your users lots of platform choices. On the other hand, when you have to | |
60 | take advantage of some unique feature of a particular platform, as is | |
61 | often the case with systems programming (whether for Unix, Windows, | |
62 | S<Mac OS>, VMS, etc.), consider writing platform-specific code. | |
63 | ||
b7df3edc GS |
64 | When the code will run on only two or three operating systems, you |
65 | may need to consider only the differences of those particular systems. | |
66 | The important thing is to decide where the code will run and to be | |
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67 | deliberate in your decision. |
68 | ||
69 | The material below is separated into three main sections: main issues of | |
70 | portability (L<"ISSUES">, platform-specific issues (L<"PLATFORMS">, and | |
b7df3edc | 71 | built-in perl functions that behave differently on various ports |
0a47030a | 72 | (L<"FUNCTION IMPLEMENTATIONS">. |
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73 | |
74 | This information should not be considered complete; it includes possibly | |
b8099c3d | 75 | transient information about idiosyncrasies of some of the ports, almost |
b7df3edc | 76 | all of which are in a state of constant evolution. Thus, this material |
e41182b5 | 77 | should be considered a perpetual work in progress |
c47ff5f1 | 78 | (<IMG SRC="yellow_sign.gif" ALT="Under Construction">). |
e41182b5 | 79 | |
e41182b5 GS |
80 | =head1 ISSUES |
81 | ||
82 | =head2 Newlines | |
83 | ||
638bc118 | 84 | In most operating systems, lines in files are terminated by newlines. |
e41182b5 | 85 | Just what is used as a newline may vary from OS to OS. Unix |
b7df3edc | 86 | traditionally uses C<\012>, one type of DOSish I/O uses C<\015\012>, |
e41182b5 GS |
87 | and S<Mac OS> uses C<\015>. |
88 | ||
b7df3edc GS |
89 | Perl uses C<\n> to represent the "logical" newline, where what is |
90 | logical may depend on the platform in use. In MacPerl, C<\n> always | |
91 | means C<\015>. In DOSish perls, C<\n> usually means C<\012>, but | |
92 | when accessing a file in "text" mode, STDIO translates it to (or | |
56d7751a | 93 | from) C<\015\012>, depending on whether you're reading or writing. |
b7df3edc GS |
94 | Unix does the same thing on ttys in canonical mode. C<\015\012> |
95 | is commonly referred to as CRLF. | |
96 | ||
5b3eff12 MS |
97 | A common cause of unportable programs is the misuse of chop() to trim |
98 | newlines: | |
99 | ||
100 | # XXX UNPORTABLE! | |
101 | while(<FILE>) { | |
102 | chop; | |
103 | @array = split(/:/); | |
104 | #... | |
105 | } | |
106 | ||
107 | You can get away with this on Unix and MacOS (they have a single | |
108 | character end-of-line), but the same program will break under DOSish | |
109 | perls because you're only chop()ing half the end-of-line. Instead, | |
110 | chomp() should be used to trim newlines. The Dunce::Files module can | |
111 | help audit your code for misuses of chop(). | |
112 | ||
113 | When dealing with binary files (or text files in binary mode) be sure | |
114 | to explicitly set $/ to the appropriate value for your file format | |
115 | before using chomp(). | |
116 | ||
b7df3edc GS |
117 | Because of the "text" mode translation, DOSish perls have limitations |
118 | in using C<seek> and C<tell> on a file accessed in "text" mode. | |
119 | Stick to C<seek>-ing to locations you got from C<tell> (and no | |
120 | others), and you are usually free to use C<seek> and C<tell> even | |
121 | in "text" mode. Using C<seek> or C<tell> or other file operations | |
122 | may be non-portable. If you use C<binmode> on a file, however, you | |
123 | can usually C<seek> and C<tell> with arbitrary values in safety. | |
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124 | |
125 | A common misconception in socket programming is that C<\n> eq C<\012> | |
0a47030a | 126 | everywhere. When using protocols such as common Internet protocols, |
e41182b5 GS |
127 | C<\012> and C<\015> are called for specifically, and the values of |
128 | the logical C<\n> and C<\r> (carriage return) are not reliable. | |
129 | ||
130 | print SOCKET "Hi there, client!\r\n"; # WRONG | |
131 | print SOCKET "Hi there, client!\015\012"; # RIGHT | |
132 | ||
0a47030a GS |
133 | However, using C<\015\012> (or C<\cM\cJ>, or C<\x0D\x0A>) can be tedious |
134 | and unsightly, as well as confusing to those maintaining the code. As | |
6ab3f9cb | 135 | such, the Socket module supplies the Right Thing for those who want it. |
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136 | |
137 | use Socket qw(:DEFAULT :crlf); | |
138 | print SOCKET "Hi there, client!$CRLF" # RIGHT | |
139 | ||
6ab3f9cb | 140 | When reading from a socket, remember that the default input record |
b7df3edc GS |
141 | separator C<$/> is C<\n>, but robust socket code will recognize as |
142 | either C<\012> or C<\015\012> as end of line: | |
e41182b5 GS |
143 | |
144 | while (<SOCKET>) { | |
145 | # ... | |
146 | } | |
147 | ||
b7df3edc GS |
148 | Because both CRLF and LF end in LF, the input record separator can |
149 | be set to LF and any CR stripped later. Better to write: | |
e41182b5 GS |
150 | |
151 | use Socket qw(:DEFAULT :crlf); | |
152 | local($/) = LF; # not needed if $/ is already \012 | |
153 | ||
154 | while (<SOCKET>) { | |
155 | s/$CR?$LF/\n/; # not sure if socket uses LF or CRLF, OK | |
156 | # s/\015?\012/\n/; # same thing | |
157 | } | |
158 | ||
b7df3edc GS |
159 | This example is preferred over the previous one--even for Unix |
160 | platforms--because now any C<\015>'s (C<\cM>'s) are stripped out | |
e41182b5 GS |
161 | (and there was much rejoicing). |
162 | ||
6ab3f9cb | 163 | Similarly, functions that return text data--such as a function that |
b7df3edc GS |
164 | fetches a web page--should sometimes translate newlines before |
165 | returning the data, if they've not yet been translated to the local | |
166 | newline representation. A single line of code will often suffice: | |
2ee0eb3c | 167 | |
b7df3edc GS |
168 | $data =~ s/\015?\012/\n/g; |
169 | return $data; | |
2ee0eb3c | 170 | |
6ab3f9cb GS |
171 | Some of this may be confusing. Here's a handy reference to the ASCII CR |
172 | and LF characters. You can print it out and stick it in your wallet. | |
173 | ||
174 | LF == \012 == \x0A == \cJ == ASCII 10 | |
175 | CR == \015 == \x0D == \cM == ASCII 13 | |
176 | ||
177 | | Unix | DOS | Mac | | |
178 | --------------------------- | |
179 | \n | LF | LF | CR | | |
180 | \r | CR | CR | LF | | |
181 | \n * | LF | CRLF | CR | | |
182 | \r * | CR | CR | LF | | |
183 | --------------------------- | |
184 | * text-mode STDIO | |
185 | ||
b7df3edc GS |
186 | The Unix column assumes that you are not accessing a serial line |
187 | (like a tty) in canonical mode. If you are, then CR on input becomes | |
188 | "\n", and "\n" on output becomes CRLF. | |
189 | ||
6ab3f9cb GS |
190 | These are just the most common definitions of C<\n> and C<\r> in Perl. |
191 | There may well be others. | |
192 | ||
322422de GS |
193 | =head2 Numbers endianness and Width |
194 | ||
195 | Different CPUs store integers and floating point numbers in different | |
196 | orders (called I<endianness>) and widths (32-bit and 64-bit being the | |
b7df3edc GS |
197 | most common today). This affects your programs when they attempt to transfer |
198 | numbers in binary format from one CPU architecture to another, | |
199 | usually either "live" via network connection, or by storing the | |
200 | numbers to secondary storage such as a disk file or tape. | |
322422de | 201 | |
b7df3edc | 202 | Conflicting storage orders make utter mess out of the numbers. If a |
d1e3b762 | 203 | little-endian host (Intel, VAX) stores 0x12345678 (305419896 in |
b84d4f81 JH |
204 | decimal), a big-endian host (Motorola, Sparc, PA) reads it as |
205 | 0x78563412 (2018915346 in decimal). Alpha and MIPS can be either: | |
206 | Digital/Compaq used/uses them in little-endian mode; SGI/Cray uses | |
207 | them in big-endian mode. To avoid this problem in network (socket) | |
208 | connections use the C<pack> and C<unpack> formats C<n> and C<N>, the | |
209 | "network" orders. These are guaranteed to be portable. | |
322422de | 210 | |
d1e3b762 GS |
211 | You can explore the endianness of your platform by unpacking a |
212 | data structure packed in native format such as: | |
213 | ||
214 | print unpack("h*", pack("s2", 1, 2)), "\n"; | |
215 | # '10002000' on e.g. Intel x86 or Alpha 21064 in little-endian mode | |
216 | # '00100020' on e.g. Motorola 68040 | |
217 | ||
218 | If you need to distinguish between endian architectures you could use | |
219 | either of the variables set like so: | |
220 | ||
221 | $is_big_endian = unpack("h*", pack("s", 1)) =~ /01/; | |
4375e838 | 222 | $is_little_endian = unpack("h*", pack("s", 1)) =~ /^1/; |
d1e3b762 | 223 | |
b7df3edc GS |
224 | Differing widths can cause truncation even between platforms of equal |
225 | endianness. The platform of shorter width loses the upper parts of the | |
322422de GS |
226 | number. There is no good solution for this problem except to avoid |
227 | transferring or storing raw binary numbers. | |
228 | ||
b7df3edc | 229 | One can circumnavigate both these problems in two ways. Either |
322422de | 230 | transfer and store numbers always in text format, instead of raw |
b7df3edc | 231 | binary, or else consider using modules like Data::Dumper (included in |
83df6a1d JH |
232 | the standard distribution as of Perl 5.005) and Storable (included as |
233 | of perl 5.8). Keeping all data as text significantly simplifies matters. | |
322422de | 234 | |
433acd8a | 235 | =head2 Files and Filesystems |
e41182b5 GS |
236 | |
237 | Most platforms these days structure files in a hierarchical fashion. | |
b7df3edc | 238 | So, it is reasonably safe to assume that all platforms support the |
6ab3f9cb | 239 | notion of a "path" to uniquely identify a file on the system. How |
b7df3edc | 240 | that path is really written, though, differs considerably. |
e41182b5 | 241 | |
4375e838 | 242 | Although similar, file path specifications differ between Unix, |
b7df3edc GS |
243 | Windows, S<Mac OS>, OS/2, VMS, VOS, S<RISC OS>, and probably others. |
244 | Unix, for example, is one of the few OSes that has the elegant idea | |
245 | of a single root directory. | |
322422de | 246 | |
6ab3f9cb GS |
247 | DOS, OS/2, VMS, VOS, and Windows can work similarly to Unix with C</> |
248 | as path separator, or in their own idiosyncratic ways (such as having | |
249 | several root directories and various "unrooted" device files such NIL: | |
250 | and LPT:). | |
322422de GS |
251 | |
252 | S<Mac OS> uses C<:> as a path separator instead of C</>. | |
253 | ||
6ab3f9cb GS |
254 | The filesystem may support neither hard links (C<link>) nor |
255 | symbolic links (C<symlink>, C<readlink>, C<lstat>). | |
433acd8a | 256 | |
6ab3f9cb | 257 | The filesystem may support neither access timestamp nor change |
433acd8a JH |
258 | timestamp (meaning that about the only portable timestamp is the |
259 | modification timestamp), or one second granularity of any timestamps | |
260 | (e.g. the FAT filesystem limits the time granularity to two seconds). | |
261 | ||
495c5fdc PG |
262 | VOS perl can emulate Unix filenames with C</> as path separator. The |
263 | native pathname characters greater-than, less-than, number-sign, and | |
264 | percent-sign are always accepted. | |
265 | ||
6ab3f9cb | 266 | S<RISC OS> perl can emulate Unix filenames with C</> as path |
322422de | 267 | separator, or go native and use C<.> for path separator and C<:> to |
6ab3f9cb | 268 | signal filesystems and disk names. |
e41182b5 | 269 | |
b7df3edc GS |
270 | If all this is intimidating, have no (well, maybe only a little) |
271 | fear. There are modules that can help. The File::Spec modules | |
272 | provide methods to do the Right Thing on whatever platform happens | |
273 | to be running the program. | |
e41182b5 | 274 | |
6ab3f9cb GS |
275 | use File::Spec::Functions; |
276 | chdir(updir()); # go up one directory | |
277 | $file = catfile(curdir(), 'temp', 'file.txt'); | |
e41182b5 GS |
278 | # on Unix and Win32, './temp/file.txt' |
279 | # on Mac OS, ':temp:file.txt' | |
d1e3b762 | 280 | # on VMS, '[.temp]file.txt' |
e41182b5 | 281 | |
b7df3edc | 282 | File::Spec is available in the standard distribution as of version |
d1e3b762 GS |
283 | 5.004_05. File::Spec::Functions is only in File::Spec 0.7 and later, |
284 | and some versions of perl come with version 0.6. If File::Spec | |
285 | is not updated to 0.7 or later, you must use the object-oriented | |
286 | interface from File::Spec (or upgrade File::Spec). | |
e41182b5 | 287 | |
b7df3edc GS |
288 | In general, production code should not have file paths hardcoded. |
289 | Making them user-supplied or read from a configuration file is | |
290 | better, keeping in mind that file path syntax varies on different | |
291 | machines. | |
e41182b5 GS |
292 | |
293 | This is especially noticeable in scripts like Makefiles and test suites, | |
294 | which often assume C</> as a path separator for subdirectories. | |
295 | ||
b7df3edc | 296 | Also of use is File::Basename from the standard distribution, which |
e41182b5 GS |
297 | splits a pathname into pieces (base filename, full path to directory, |
298 | and file suffix). | |
299 | ||
19799a22 | 300 | Even when on a single platform (if you can call Unix a single platform), |
b7df3edc | 301 | remember not to count on the existence or the contents of particular |
3c075c7d | 302 | system-specific files or directories, like F</etc/passwd>, |
b7df3edc GS |
303 | F</etc/sendmail.conf>, F</etc/resolv.conf>, or even F</tmp/>. For |
304 | example, F</etc/passwd> may exist but not contain the encrypted | |
305 | passwords, because the system is using some form of enhanced security. | |
306 | Or it may not contain all the accounts, because the system is using NIS. | |
3c075c7d | 307 | If code does need to rely on such a file, include a description of the |
b7df3edc | 308 | file and its format in the code's documentation, then make it easy for |
3c075c7d CN |
309 | the user to override the default location of the file. |
310 | ||
b7df3edc GS |
311 | Don't assume a text file will end with a newline. They should, |
312 | but people forget. | |
e41182b5 | 313 | |
dd9f0070 | 314 | Do not have two files of the same name with different case, like |
3c075c7d | 315 | F<test.pl> and F<Test.pl>, as many platforms have case-insensitive |
dd9f0070 | 316 | filenames. Also, try not to have non-word characters (except for C<.>) |
0a47030a | 317 | in the names, and keep them to the 8.3 convention, for maximum |
b7df3edc | 318 | portability, onerous a burden though this may appear. |
dd9f0070 | 319 | |
b7df3edc GS |
320 | Likewise, when using the AutoSplit module, try to keep your functions to |
321 | 8.3 naming and case-insensitive conventions; or, at the least, | |
dd9f0070 CN |
322 | make it so the resulting files have a unique (case-insensitively) |
323 | first 8 characters. | |
324 | ||
b7df3edc GS |
325 | Whitespace in filenames is tolerated on most systems, but not all. |
326 | Many systems (DOS, VMS) cannot have more than one C<.> in their filenames. | |
433acd8a | 327 | |
c47ff5f1 GS |
328 | Don't assume C<< > >> won't be the first character of a filename. |
329 | Always use C<< < >> explicitly to open a file for reading, | |
b7df3edc | 330 | unless you want the user to be able to specify a pipe open. |
0a47030a | 331 | |
6ab3f9cb | 332 | open(FILE, "< $existing_file") or die $!; |
0a47030a | 333 | |
6ab3f9cb GS |
334 | If filenames might use strange characters, it is safest to open it |
335 | with C<sysopen> instead of C<open>. C<open> is magic and can | |
c47ff5f1 | 336 | translate characters like C<< > >>, C<< < >>, and C<|>, which may |
b7df3edc | 337 | be the wrong thing to do. (Sometimes, though, it's the right thing.) |
e41182b5 GS |
338 | |
339 | =head2 System Interaction | |
340 | ||
b7df3edc GS |
341 | Not all platforms provide a command line. These are usually platforms |
342 | that rely primarily on a Graphical User Interface (GUI) for user | |
343 | interaction. A program requiring a command line interface might | |
344 | not work everywhere. This is probably for the user of the program | |
345 | to deal with, so don't stay up late worrying about it. | |
e41182b5 | 346 | |
b7df3edc GS |
347 | Some platforms can't delete or rename files held open by the system. |
348 | Remember to C<close> files when you are done with them. Don't | |
349 | C<unlink> or C<rename> an open file. Don't C<tie> or C<open> a | |
350 | file already tied or opened; C<untie> or C<close> it first. | |
e41182b5 | 351 | |
0a47030a GS |
352 | Don't open the same file more than once at a time for writing, as some |
353 | operating systems put mandatory locks on such files. | |
354 | ||
e41182b5 | 355 | Don't count on a specific environment variable existing in C<%ENV>. |
0a47030a | 356 | Don't count on C<%ENV> entries being case-sensitive, or even |
4a0d0822 | 357 | case-preserving. Don't try to clear %ENV by saying C<%ENV = ();>, or, |
6be8f7a6 | 358 | if you really have to, make it conditional on C<$^O ne 'VMS'> since in |
4a0d0822 JH |
359 | VMS the C<%ENV> table is much more than a per-process key-value string |
360 | table. | |
e41182b5 | 361 | |
d1e3b762 | 362 | Don't count on signals or C<%SIG> for anything. |
e41182b5 GS |
363 | |
364 | Don't count on filename globbing. Use C<opendir>, C<readdir>, and | |
365 | C<closedir> instead. | |
366 | ||
b8099c3d | 367 | Don't count on per-program environment variables, or per-program current |
dd9f0070 | 368 | directories. |
b8099c3d | 369 | |
3c075c7d CN |
370 | Don't count on specific values of C<$!>. |
371 | ||
e41182b5 GS |
372 | =head2 Interprocess Communication (IPC) |
373 | ||
b7df3edc GS |
374 | In general, don't directly access the system in code meant to be |
375 | portable. That means, no C<system>, C<exec>, C<fork>, C<pipe>, | |
376 | C<``>, C<qx//>, C<open> with a C<|>, nor any of the other things | |
377 | that makes being a perl hacker worth being. | |
e41182b5 GS |
378 | |
379 | Commands that launch external processes are generally supported on | |
b7df3edc GS |
380 | most platforms (though many of them do not support any type of |
381 | forking). The problem with using them arises from what you invoke | |
382 | them on. External tools are often named differently on different | |
4375e838 | 383 | platforms, may not be available in the same location, might accept |
b7df3edc GS |
384 | different arguments, can behave differently, and often present their |
385 | results in a platform-dependent way. Thus, you should seldom depend | |
386 | on them to produce consistent results. (Then again, if you're calling | |
387 | I<netstat -a>, you probably don't expect it to run on both Unix and CP/M.) | |
e41182b5 | 388 | |
b7df3edc | 389 | One especially common bit of Perl code is opening a pipe to B<sendmail>: |
e41182b5 | 390 | |
b7df3edc GS |
391 | open(MAIL, '|/usr/lib/sendmail -t') |
392 | or die "cannot fork sendmail: $!"; | |
e41182b5 GS |
393 | |
394 | This is fine for systems programming when sendmail is known to be | |
395 | available. But it is not fine for many non-Unix systems, and even | |
396 | some Unix systems that may not have sendmail installed. If a portable | |
b7df3edc GS |
397 | solution is needed, see the various distributions on CPAN that deal |
398 | with it. Mail::Mailer and Mail::Send in the MailTools distribution are | |
399 | commonly used, and provide several mailing methods, including mail, | |
400 | sendmail, and direct SMTP (via Net::SMTP) if a mail transfer agent is | |
401 | not available. Mail::Sendmail is a standalone module that provides | |
402 | simple, platform-independent mailing. | |
403 | ||
404 | The Unix System V IPC (C<msg*(), sem*(), shm*()>) is not available | |
405 | even on all Unix platforms. | |
e41182b5 GS |
406 | |
407 | The rule of thumb for portable code is: Do it all in portable Perl, or | |
0a47030a GS |
408 | use a module (that may internally implement it with platform-specific |
409 | code, but expose a common interface). | |
e41182b5 | 410 | |
e41182b5 GS |
411 | =head2 External Subroutines (XS) |
412 | ||
b7df3edc | 413 | XS code can usually be made to work with any platform, but dependent |
e41182b5 GS |
414 | libraries, header files, etc., might not be readily available or |
415 | portable, or the XS code itself might be platform-specific, just as Perl | |
416 | code might be. If the libraries and headers are portable, then it is | |
417 | normally reasonable to make sure the XS code is portable, too. | |
418 | ||
b7df3edc GS |
419 | A different type of portability issue arises when writing XS code: |
420 | availability of a C compiler on the end-user's system. C brings | |
421 | with it its own portability issues, and writing XS code will expose | |
422 | you to some of those. Writing purely in Perl is an easier way to | |
e41182b5 GS |
423 | achieve portability. |
424 | ||
e41182b5 GS |
425 | =head2 Standard Modules |
426 | ||
427 | In general, the standard modules work across platforms. Notable | |
6ab3f9cb | 428 | exceptions are the CPAN module (which currently makes connections to external |
e41182b5 | 429 | programs that may not be available), platform-specific modules (like |
6ab3f9cb | 430 | ExtUtils::MM_VMS), and DBM modules. |
e41182b5 | 431 | |
b7df3edc | 432 | There is no one DBM module available on all platforms. |
6ab3f9cb GS |
433 | SDBM_File and the others are generally available on all Unix and DOSish |
434 | ports, but not in MacPerl, where only NBDM_File and DB_File are | |
0a47030a | 435 | available. |
e41182b5 GS |
436 | |
437 | The good news is that at least some DBM module should be available, and | |
6ab3f9cb | 438 | AnyDBM_File will use whichever module it can find. Of course, then |
b7df3edc GS |
439 | the code needs to be fairly strict, dropping to the greatest common |
440 | factor (e.g., not exceeding 1K for each record), so that it will | |
6ab3f9cb | 441 | work with any DBM module. See L<AnyDBM_File> for more details. |
e41182b5 | 442 | |
e41182b5 GS |
443 | =head2 Time and Date |
444 | ||
0a47030a | 445 | The system's notion of time of day and calendar date is controlled in |
b7df3edc | 446 | widely different ways. Don't assume the timezone is stored in C<$ENV{TZ}>, |
0a47030a GS |
447 | and even if it is, don't assume that you can control the timezone through |
448 | that variable. | |
e41182b5 | 449 | |
322422de | 450 | Don't assume that the epoch starts at 00:00:00, January 1, 1970, |
6ab3f9cb GS |
451 | because that is OS- and implementation-specific. It is better to store a date |
452 | in an unambiguous representation. The ISO-8601 standard defines | |
453 | "YYYY-MM-DD" as the date format. A text representation (like "1987-12-18") | |
454 | can be easily converted into an OS-specific value using a module like | |
455 | Date::Parse. An array of values, such as those returned by | |
322422de | 456 | C<localtime>, can be converted to an OS-specific representation using |
6ab3f9cb | 457 | Time::Local. |
322422de | 458 | |
19799a22 GS |
459 | When calculating specific times, such as for tests in time or date modules, |
460 | it may be appropriate to calculate an offset for the epoch. | |
b7df3edc | 461 | |
19799a22 GS |
462 | require Time::Local; |
463 | $offset = Time::Local::timegm(0, 0, 0, 1, 0, 70); | |
b7df3edc | 464 | |
19799a22 GS |
465 | The value for C<$offset> in Unix will be C<0>, but in Mac OS will be |
466 | some large number. C<$offset> can then be added to a Unix time value | |
467 | to get what should be the proper value on any system. | |
322422de GS |
468 | |
469 | =head2 Character sets and character encoding | |
470 | ||
b7df3edc GS |
471 | Assume little about character sets. Assume nothing about |
472 | numerical values (C<ord>, C<chr>) of characters. Do not | |
322422de | 473 | assume that the alphabetic characters are encoded contiguously (in |
b7df3edc | 474 | the numeric sense). Do not assume anything about the ordering of the |
322422de | 475 | characters. The lowercase letters may come before or after the |
b7df3edc GS |
476 | uppercase letters; the lowercase and uppercase may be interlaced so |
477 | that both `a' and `A' come before `b'; the accented and other | |
322422de | 478 | international characters may be interlaced so that E<auml> comes |
b7df3edc | 479 | before `b'. |
322422de GS |
480 | |
481 | =head2 Internationalisation | |
482 | ||
b7df3edc GS |
483 | If you may assume POSIX (a rather large assumption), you may read |
484 | more about the POSIX locale system from L<perllocale>. The locale | |
485 | system at least attempts to make things a little bit more portable, | |
486 | or at least more convenient and native-friendly for non-English | |
487 | users. The system affects character sets and encoding, and date | |
488 | and time formatting--amongst other things. | |
e41182b5 GS |
489 | |
490 | =head2 System Resources | |
491 | ||
0a47030a GS |
492 | If your code is destined for systems with severely constrained (or |
493 | missing!) virtual memory systems then you want to be I<especially> mindful | |
494 | of avoiding wasteful constructs such as: | |
e41182b5 GS |
495 | |
496 | # NOTE: this is no longer "bad" in perl5.005 | |
497 | for (0..10000000) {} # bad | |
498 | for (my $x = 0; $x <= 10000000; ++$x) {} # good | |
499 | ||
500 | @lines = <VERY_LARGE_FILE>; # bad | |
501 | ||
502 | while (<FILE>) {$file .= $_} # sometimes bad | |
0a47030a | 503 | $file = join('', <FILE>); # better |
e41182b5 | 504 | |
b7df3edc GS |
505 | The last two constructs may appear unintuitive to most people. The |
506 | first repeatedly grows a string, whereas the second allocates a | |
507 | large chunk of memory in one go. On some systems, the second is | |
508 | more efficient that the first. | |
0a47030a | 509 | |
e41182b5 GS |
510 | =head2 Security |
511 | ||
b7df3edc GS |
512 | Most multi-user platforms provide basic levels of security, usually |
513 | implemented at the filesystem level. Some, however, do | |
514 | not--unfortunately. Thus the notion of user id, or "home" directory, | |
515 | or even the state of being logged-in, may be unrecognizable on many | |
516 | platforms. If you write programs that are security-conscious, it | |
517 | is usually best to know what type of system you will be running | |
518 | under so that you can write code explicitly for that platform (or | |
519 | class of platforms). | |
0a47030a | 520 | |
e41182b5 GS |
521 | =head2 Style |
522 | ||
523 | For those times when it is necessary to have platform-specific code, | |
524 | consider keeping the platform-specific code in one place, making porting | |
6ab3f9cb | 525 | to other platforms easier. Use the Config module and the special |
0a47030a GS |
526 | variable C<$^O> to differentiate platforms, as described in |
527 | L<"PLATFORMS">. | |
e41182b5 | 528 | |
b7df3edc GS |
529 | Be careful in the tests you supply with your module or programs. |
530 | Module code may be fully portable, but its tests might not be. This | |
531 | often happens when tests spawn off other processes or call external | |
532 | programs to aid in the testing, or when (as noted above) the tests | |
533 | assume certain things about the filesystem and paths. Be careful | |
534 | not to depend on a specific output style for errors, such as when | |
535 | checking C<$!> after an system call. Some platforms expect a certain | |
536 | output format, and perl on those platforms may have been adjusted | |
537 | accordingly. Most specifically, don't anchor a regex when testing | |
538 | an error value. | |
e41182b5 | 539 | |
0a47030a | 540 | =head1 CPAN Testers |
e41182b5 | 541 | |
0a47030a GS |
542 | Modules uploaded to CPAN are tested by a variety of volunteers on |
543 | different platforms. These CPAN testers are notified by mail of each | |
e41182b5 | 544 | new upload, and reply to the list with PASS, FAIL, NA (not applicable to |
0a47030a | 545 | this platform), or UNKNOWN (unknown), along with any relevant notations. |
e41182b5 GS |
546 | |
547 | The purpose of the testing is twofold: one, to help developers fix any | |
0a47030a | 548 | problems in their code that crop up because of lack of testing on other |
b7df3edc | 549 | platforms; two, to provide users with information about whether |
0a47030a | 550 | a given module works on a given platform. |
e41182b5 GS |
551 | |
552 | =over 4 | |
553 | ||
554 | =item Mailing list: cpan-testers@perl.org | |
555 | ||
c997b287 | 556 | =item Testing results: http://testers.cpan.org/ |
e41182b5 GS |
557 | |
558 | =back | |
559 | ||
e41182b5 GS |
560 | =head1 PLATFORMS |
561 | ||
562 | As of version 5.002, Perl is built with a C<$^O> variable that | |
563 | indicates the operating system it was built on. This was implemented | |
b7df3edc GS |
564 | to help speed up code that would otherwise have to C<use Config> |
565 | and use the value of C<$Config{osname}>. Of course, to get more | |
e41182b5 GS |
566 | detailed information about the system, looking into C<%Config> is |
567 | certainly recommended. | |
568 | ||
b7df3edc GS |
569 | C<%Config> cannot always be trusted, however, because it was built |
570 | at compile time. If perl was built in one place, then transferred | |
571 | elsewhere, some values may be wrong. The values may even have been | |
572 | edited after the fact. | |
6ab3f9cb | 573 | |
e41182b5 GS |
574 | =head2 Unix |
575 | ||
576 | Perl works on a bewildering variety of Unix and Unix-like platforms (see | |
577 | e.g. most of the files in the F<hints/> directory in the source code kit). | |
578 | On most of these systems, the value of C<$^O> (hence C<$Config{'osname'}>, | |
d1e3b762 GS |
579 | too) is determined either by lowercasing and stripping punctuation from the |
580 | first field of the string returned by typing C<uname -a> (or a similar command) | |
581 | at the shell prompt or by testing the file system for the presence of | |
582 | uniquely named files such as a kernel or header file. Here, for example, | |
583 | are a few of the more popular Unix flavors: | |
e41182b5 | 584 | |
b7df3edc | 585 | uname $^O $Config{'archname'} |
6ab3f9cb | 586 | -------------------------------------------- |
b7df3edc | 587 | AIX aix aix |
6ab3f9cb GS |
588 | BSD/OS bsdos i386-bsdos |
589 | dgux dgux AViiON-dgux | |
590 | DYNIX/ptx dynixptx i386-dynixptx | |
b7df3edc | 591 | FreeBSD freebsd freebsd-i386 |
d1e3b762 | 592 | Linux linux arm-linux |
b7df3edc | 593 | Linux linux i386-linux |
6ab3f9cb GS |
594 | Linux linux i586-linux |
595 | Linux linux ppc-linux | |
b7df3edc GS |
596 | HP-UX hpux PA-RISC1.1 |
597 | IRIX irix irix | |
b787fad4 | 598 | Mac OS X darwin darwin |
d1e3b762 GS |
599 | MachTen PPC machten powerpc-machten |
600 | NeXT 3 next next-fat | |
601 | NeXT 4 next OPENSTEP-Mach | |
6ab3f9cb | 602 | openbsd openbsd i386-openbsd |
b7df3edc | 603 | OSF1 dec_osf alpha-dec_osf |
6ab3f9cb GS |
604 | reliantunix-n svr4 RM400-svr4 |
605 | SCO_SV sco_sv i386-sco_sv | |
606 | SINIX-N svr4 RM400-svr4 | |
607 | sn4609 unicos CRAY_C90-unicos | |
608 | sn6521 unicosmk t3e-unicosmk | |
609 | sn9617 unicos CRAY_J90-unicos | |
b7df3edc GS |
610 | SunOS solaris sun4-solaris |
611 | SunOS solaris i86pc-solaris | |
612 | SunOS4 sunos sun4-sunos | |
e41182b5 | 613 | |
b7df3edc GS |
614 | Because the value of C<$Config{archname}> may depend on the |
615 | hardware architecture, it can vary more than the value of C<$^O>. | |
6ab3f9cb | 616 | |
e41182b5 GS |
617 | =head2 DOS and Derivatives |
618 | ||
b7df3edc | 619 | Perl has long been ported to Intel-style microcomputers running under |
e41182b5 GS |
620 | systems like PC-DOS, MS-DOS, OS/2, and most Windows platforms you can |
621 | bring yourself to mention (except for Windows CE, if you count that). | |
b7df3edc | 622 | Users familiar with I<COMMAND.COM> or I<CMD.EXE> style shells should |
e41182b5 GS |
623 | be aware that each of these file specifications may have subtle |
624 | differences: | |
625 | ||
626 | $filespec0 = "c:/foo/bar/file.txt"; | |
627 | $filespec1 = "c:\\foo\\bar\\file.txt"; | |
628 | $filespec2 = 'c:\foo\bar\file.txt'; | |
629 | $filespec3 = 'c:\\foo\\bar\\file.txt'; | |
630 | ||
b7df3edc GS |
631 | System calls accept either C</> or C<\> as the path separator. |
632 | However, many command-line utilities of DOS vintage treat C</> as | |
633 | the option prefix, so may get confused by filenames containing C</>. | |
634 | Aside from calling any external programs, C</> will work just fine, | |
635 | and probably better, as it is more consistent with popular usage, | |
636 | and avoids the problem of remembering what to backwhack and what | |
637 | not to. | |
e41182b5 | 638 | |
b7df3edc GS |
639 | The DOS FAT filesystem can accommodate only "8.3" style filenames. Under |
640 | the "case-insensitive, but case-preserving" HPFS (OS/2) and NTFS (NT) | |
0a47030a | 641 | filesystems you may have to be careful about case returned with functions |
e41182b5 GS |
642 | like C<readdir> or used with functions like C<open> or C<opendir>. |
643 | ||
b7df3edc GS |
644 | DOS also treats several filenames as special, such as AUX, PRN, |
645 | NUL, CON, COM1, LPT1, LPT2, etc. Unfortunately, sometimes these | |
646 | filenames won't even work if you include an explicit directory | |
647 | prefix. It is best to avoid such filenames, if you want your code | |
648 | to be portable to DOS and its derivatives. It's hard to know what | |
649 | these all are, unfortunately. | |
e41182b5 GS |
650 | |
651 | Users of these operating systems may also wish to make use of | |
b7df3edc | 652 | scripts such as I<pl2bat.bat> or I<pl2cmd> to |
e41182b5 GS |
653 | put wrappers around your scripts. |
654 | ||
655 | Newline (C<\n>) is translated as C<\015\012> by STDIO when reading from | |
6ab3f9cb GS |
656 | and writing to files (see L<"Newlines">). C<binmode(FILEHANDLE)> |
657 | will keep C<\n> translated as C<\012> for that filehandle. Since it is a | |
658 | no-op on other systems, C<binmode> should be used for cross-platform code | |
b7df3edc GS |
659 | that deals with binary data. That's assuming you realize in advance |
660 | that your data is in binary. General-purpose programs should | |
661 | often assume nothing about their data. | |
e41182b5 | 662 | |
b7df3edc | 663 | The C<$^O> variable and the C<$Config{archname}> values for various |
e41182b5 GS |
664 | DOSish perls are as follows: |
665 | ||
666 | OS $^O $Config{'archname'} | |
667 | -------------------------------------------- | |
668 | MS-DOS dos | |
669 | PC-DOS dos | |
670 | OS/2 os2 | |
671 | Windows 95 MSWin32 MSWin32-x86 | |
6ab3f9cb | 672 | Windows 98 MSWin32 MSWin32-x86 |
e41182b5 | 673 | Windows NT MSWin32 MSWin32-x86 |
6ab3f9cb | 674 | Windows NT MSWin32 MSWin32-ALPHA |
e41182b5 | 675 | Windows NT MSWin32 MSWin32-ppc |
b4bc034f | 676 | Cygwin cygwin |
e41182b5 | 677 | |
34aaaa84 PP |
678 | The various MSWin32 Perl's can distinguish the OS they are running on |
679 | via the value of the fifth element of the list returned from | |
680 | Win32::GetOSVersion(). For example: | |
681 | ||
682 | if ($^O eq 'MSWin32') { | |
683 | my @os_version_info = Win32::GetOSVersion(); | |
684 | print +('3.1','95','NT')[$os_version_info[4]],"\n"; | |
685 | } | |
686 | ||
e41182b5 GS |
687 | Also see: |
688 | ||
689 | =over 4 | |
690 | ||
c997b287 | 691 | =item * |
e41182b5 | 692 | |
c997b287 GS |
693 | The djgpp environment for DOS, http://www.delorie.com/djgpp/ |
694 | and L<perldos>. | |
e41182b5 | 695 | |
c997b287 | 696 | =item * |
e41182b5 | 697 | |
c997b287 GS |
698 | The EMX environment for DOS, OS/2, etc. emx@iaehv.nl, |
699 | http://www.leo.org/pub/comp/os/os2/leo/gnu/emx+gcc/index.html or | |
700 | ftp://hobbes.nmsu.edu/pub/os2/dev/emx. Also L<perlos2>. | |
e41182b5 | 701 | |
c997b287 | 702 | =item * |
d1e3b762 | 703 | |
c997b287 GS |
704 | Build instructions for Win32 in L<perlwin32>, or under the Cygnus environment |
705 | in L<perlcygwin>. | |
706 | ||
707 | =item * | |
708 | ||
709 | The C<Win32::*> modules in L<Win32>. | |
710 | ||
711 | =item * | |
712 | ||
713 | The ActiveState Pages, http://www.activestate.com/ | |
714 | ||
715 | =item * | |
716 | ||
717 | The Cygwin environment for Win32; F<README.cygwin> (installed | |
47dafe4d | 718 | as L<perlcygwin>), http://www.cygwin.com/ |
c997b287 GS |
719 | |
720 | =item * | |
721 | ||
722 | The U/WIN environment for Win32, | |
cea6626f | 723 | http://www.research.att.com/sw/tools/uwin/ |
c997b287 | 724 | |
cea6626f | 725 | =item * |
d1e3b762 | 726 | |
cea6626f | 727 | Build instructions for OS/2, L<perlos2> |
d1e3b762 | 728 | |
e41182b5 GS |
729 | =back |
730 | ||
dd9f0070 | 731 | =head2 S<Mac OS> |
e41182b5 GS |
732 | |
733 | Any module requiring XS compilation is right out for most people, because | |
734 | MacPerl is built using non-free (and non-cheap!) compilers. Some XS | |
735 | modules that can work with MacPerl are built and distributed in binary | |
6ab3f9cb | 736 | form on CPAN. |
e41182b5 GS |
737 | |
738 | Directories are specified as: | |
739 | ||
740 | volume:folder:file for absolute pathnames | |
741 | volume:folder: for absolute pathnames | |
742 | :folder:file for relative pathnames | |
743 | :folder: for relative pathnames | |
744 | :file for relative pathnames | |
745 | file for relative pathnames | |
746 | ||
b7df3edc | 747 | Files are stored in the directory in alphabetical order. Filenames are |
6ab3f9cb | 748 | limited to 31 characters, and may include any character except for |
b7df3edc | 749 | null and C<:>, which is reserved as the path separator. |
e41182b5 | 750 | |
0a47030a | 751 | Instead of C<flock>, see C<FSpSetFLock> and C<FSpRstFLock> in the |
6ab3f9cb | 752 | Mac::Files module, or C<chmod(0444, ...)> and C<chmod(0666, ...)>. |
e41182b5 GS |
753 | |
754 | In the MacPerl application, you can't run a program from the command line; | |
755 | programs that expect C<@ARGV> to be populated can be edited with something | |
756 | like the following, which brings up a dialog box asking for the command | |
757 | line arguments. | |
758 | ||
759 | if (!@ARGV) { | |
760 | @ARGV = split /\s+/, MacPerl::Ask('Arguments?'); | |
761 | } | |
762 | ||
b7df3edc | 763 | A MacPerl script saved as a "droplet" will populate C<@ARGV> with the full |
e41182b5 GS |
764 | pathnames of the files dropped onto the script. |
765 | ||
b7df3edc GS |
766 | Mac users can run programs under a type of command line interface |
767 | under MPW (Macintosh Programmer's Workshop, a free development | |
768 | environment from Apple). MacPerl was first introduced as an MPW | |
769 | tool, and MPW can be used like a shell: | |
e41182b5 GS |
770 | |
771 | perl myscript.plx some arguments | |
772 | ||
773 | ToolServer is another app from Apple that provides access to MPW tools | |
0a47030a | 774 | from MPW and the MacPerl app, which allows MacPerl programs to use |
e41182b5 GS |
775 | C<system>, backticks, and piped C<open>. |
776 | ||
777 | "S<Mac OS>" is the proper name for the operating system, but the value | |
778 | in C<$^O> is "MacOS". To determine architecture, version, or whether | |
779 | the application or MPW tool version is running, check: | |
780 | ||
781 | $is_app = $MacPerl::Version =~ /App/; | |
782 | $is_tool = $MacPerl::Version =~ /MPW/; | |
783 | ($version) = $MacPerl::Version =~ /^(\S+)/; | |
784 | $is_ppc = $MacPerl::Architecture eq 'MacPPC'; | |
785 | $is_68k = $MacPerl::Architecture eq 'Mac68K'; | |
786 | ||
b787fad4 JH |
787 | S<Mac OS X>, based on NeXT's OpenStep OS, runs MacPerl natively, under the |
788 | "Classic" environment. There is no "Carbon" version of MacPerl to run | |
789 | under the primary Mac OS X environment. S<Mac OS X> and its Open Source | |
790 | version, Darwin, both run Unix perl natively. | |
6ab3f9cb | 791 | |
e41182b5 GS |
792 | Also see: |
793 | ||
794 | =over 4 | |
795 | ||
c997b287 GS |
796 | =item * |
797 | ||
862b5365 | 798 | MacPerl Development, http://dev.macperl.org/ . |
c997b287 GS |
799 | |
800 | =item * | |
801 | ||
862b5365 | 802 | The MacPerl Pages, http://www.macperl.com/ . |
e41182b5 | 803 | |
c997b287 | 804 | =item * |
6ab3f9cb | 805 | |
862b5365 | 806 | The MacPerl mailing lists, http://lists.perl.org/ . |
e41182b5 GS |
807 | |
808 | =back | |
809 | ||
e41182b5 GS |
810 | =head2 VMS |
811 | ||
c997b287 | 812 | Perl on VMS is discussed in L<perlvms> in the perl distribution. |
b7df3edc | 813 | Perl on VMS can accept either VMS- or Unix-style file |
e41182b5 GS |
814 | specifications as in either of the following: |
815 | ||
816 | $ perl -ne "print if /perl_setup/i" SYS$LOGIN:LOGIN.COM | |
817 | $ perl -ne "print if /perl_setup/i" /sys$login/login.com | |
818 | ||
819 | but not a mixture of both as in: | |
820 | ||
821 | $ perl -ne "print if /perl_setup/i" sys$login:/login.com | |
822 | Can't open sys$login:/login.com: file specification syntax error | |
823 | ||
824 | Interacting with Perl from the Digital Command Language (DCL) shell | |
825 | often requires a different set of quotation marks than Unix shells do. | |
826 | For example: | |
827 | ||
828 | $ perl -e "print ""Hello, world.\n""" | |
829 | Hello, world. | |
830 | ||
b7df3edc | 831 | There are several ways to wrap your perl scripts in DCL F<.COM> files, if |
e41182b5 GS |
832 | you are so inclined. For example: |
833 | ||
834 | $ write sys$output "Hello from DCL!" | |
835 | $ if p1 .eqs. "" | |
836 | $ then perl -x 'f$environment("PROCEDURE") | |
837 | $ else perl -x - 'p1 'p2 'p3 'p4 'p5 'p6 'p7 'p8 | |
838 | $ deck/dollars="__END__" | |
839 | #!/usr/bin/perl | |
840 | ||
841 | print "Hello from Perl!\n"; | |
842 | ||
843 | __END__ | |
844 | $ endif | |
845 | ||
846 | Do take care with C<$ ASSIGN/nolog/user SYS$COMMAND: SYS$INPUT> if your | |
c47ff5f1 | 847 | perl-in-DCL script expects to do things like C<< $read = <STDIN>; >>. |
e41182b5 GS |
848 | |
849 | Filenames are in the format "name.extension;version". The maximum | |
850 | length for filenames is 39 characters, and the maximum length for | |
851 | extensions is also 39 characters. Version is a number from 1 to | |
852 | 32767. Valid characters are C</[A-Z0-9$_-]/>. | |
853 | ||
b7df3edc | 854 | VMS's RMS filesystem is case-insensitive and does not preserve case. |
e41182b5 | 855 | C<readdir> returns lowercased filenames, but specifying a file for |
b7df3edc | 856 | opening remains case-insensitive. Files without extensions have a |
e41182b5 | 857 | trailing period on them, so doing a C<readdir> with a file named F<A.;5> |
0a47030a GS |
858 | will return F<a.> (though that file could be opened with |
859 | C<open(FH, 'A')>). | |
e41182b5 | 860 | |
f34d0673 | 861 | RMS had an eight level limit on directory depths from any rooted logical |
dd9f0070 CN |
862 | (allowing 16 levels overall) prior to VMS 7.2. Hence |
863 | C<PERL_ROOT:[LIB.2.3.4.5.6.7.8]> is a valid directory specification but | |
864 | C<PERL_ROOT:[LIB.2.3.4.5.6.7.8.9]> is not. F<Makefile.PL> authors might | |
865 | have to take this into account, but at least they can refer to the former | |
f34d0673 | 866 | as C</PERL_ROOT/lib/2/3/4/5/6/7/8/>. |
e41182b5 | 867 | |
6ab3f9cb | 868 | The VMS::Filespec module, which gets installed as part of the build |
0a47030a GS |
869 | process on VMS, is a pure Perl module that can easily be installed on |
870 | non-VMS platforms and can be helpful for conversions to and from RMS | |
871 | native formats. | |
e41182b5 | 872 | |
5e12dbfa PP |
873 | What C<\n> represents depends on the type of file opened. It usually |
874 | represents C<\012> but it could also be C<\015>, C<\012>, C<\015\012>, | |
875 | C<\000>, C<\040>, or nothing depending on the file organiztion and | |
876 | record format. The VMS::Stdio module provides access to the | |
877 | special fopen() requirements of files with unusual attributes on VMS. | |
e41182b5 GS |
878 | |
879 | TCP/IP stacks are optional on VMS, so socket routines might not be | |
880 | implemented. UDP sockets may not be supported. | |
881 | ||
882 | The value of C<$^O> on OpenVMS is "VMS". To determine the architecture | |
883 | that you are running on without resorting to loading all of C<%Config> | |
884 | you can examine the content of the C<@INC> array like so: | |
885 | ||
886 | if (grep(/VMS_AXP/, @INC)) { | |
887 | print "I'm on Alpha!\n"; | |
6ab3f9cb | 888 | |
e41182b5 GS |
889 | } elsif (grep(/VMS_VAX/, @INC)) { |
890 | print "I'm on VAX!\n"; | |
6ab3f9cb | 891 | |
e41182b5 GS |
892 | } else { |
893 | print "I'm not so sure about where $^O is...\n"; | |
894 | } | |
895 | ||
b7df3edc GS |
896 | On VMS, perl determines the UTC offset from the C<SYS$TIMEZONE_DIFFERENTIAL> |
897 | logical name. Although the VMS epoch began at 17-NOV-1858 00:00:00.00, | |
6ab3f9cb | 898 | calls to C<localtime> are adjusted to count offsets from |
b7df3edc | 899 | 01-JAN-1970 00:00:00.00, just like Unix. |
6ab3f9cb | 900 | |
e41182b5 GS |
901 | Also see: |
902 | ||
903 | =over 4 | |
904 | ||
c997b287 GS |
905 | =item * |
906 | ||
907 | F<README.vms> (installed as L<README_vms>), L<perlvms> | |
908 | ||
909 | =item * | |
910 | ||
911 | vmsperl list, majordomo@perl.org | |
e41182b5 | 912 | |
c997b287 | 913 | (Put the words C<subscribe vmsperl> in message body.) |
e41182b5 | 914 | |
c997b287 | 915 | =item * |
e41182b5 | 916 | |
c997b287 | 917 | vmsperl on the web, http://www.sidhe.org/vmsperl/index.html |
e41182b5 GS |
918 | |
919 | =back | |
920 | ||
495c5fdc PG |
921 | =head2 VOS |
922 | ||
9a997319 JH |
923 | Perl on VOS is discussed in F<README.vos> in the perl distribution |
924 | (installed as L<perlvos>). Perl on VOS can accept either VOS- or | |
925 | Unix-style file specifications as in either of the following: | |
495c5fdc PG |
926 | |
927 | $ perl -ne "print if /perl_setup/i" >system>notices | |
928 | $ perl -ne "print if /perl_setup/i" /system/notices | |
929 | ||
930 | or even a mixture of both as in: | |
931 | ||
932 | $ perl -ne "print if /perl_setup/i" >system/notices | |
933 | ||
b7df3edc | 934 | Even though VOS allows the slash character to appear in object |
495c5fdc PG |
935 | names, because the VOS port of Perl interprets it as a pathname |
936 | delimiting character, VOS files, directories, or links whose names | |
937 | contain a slash character cannot be processed. Such files must be | |
a3dfe201 GS |
938 | renamed before they can be processed by Perl. Note that VOS limits |
939 | file names to 32 or fewer characters. | |
495c5fdc | 940 | |
5b8c1387 JH |
941 | See F<README.vos> for restrictions that apply when Perl is built |
942 | with the alpha version of VOS POSIX.1 support. | |
943 | ||
944 | Perl on VOS is built without any extensions and does not support | |
945 | dynamic loading. | |
495c5fdc PG |
946 | |
947 | The value of C<$^O> on VOS is "VOS". To determine the architecture that | |
948 | you are running on without resorting to loading all of C<%Config> you | |
c997b287 | 949 | can examine the content of the @INC array like so: |
495c5fdc | 950 | |
24e8e380 | 951 | if ($^O =~ /VOS/) { |
495c5fdc PG |
952 | print "I'm on a Stratus box!\n"; |
953 | } else { | |
954 | print "I'm not on a Stratus box!\n"; | |
955 | die; | |
956 | } | |
957 | ||
958 | if (grep(/860/, @INC)) { | |
959 | print "This box is a Stratus XA/R!\n"; | |
6ab3f9cb | 960 | |
495c5fdc | 961 | } elsif (grep(/7100/, @INC)) { |
24e8e380 | 962 | print "This box is a Stratus HP 7100 or 8xxx!\n"; |
6ab3f9cb | 963 | |
495c5fdc | 964 | } elsif (grep(/8000/, @INC)) { |
24e8e380 | 965 | print "This box is a Stratus HP 8xxx!\n"; |
6ab3f9cb | 966 | |
495c5fdc | 967 | } else { |
24e8e380 | 968 | print "This box is a Stratus 68K!\n"; |
495c5fdc PG |
969 | } |
970 | ||
971 | Also see: | |
972 | ||
973 | =over 4 | |
974 | ||
c997b287 | 975 | =item * |
495c5fdc | 976 | |
c997b287 GS |
977 | F<README.vos> |
978 | ||
979 | =item * | |
980 | ||
981 | The VOS mailing list. | |
495c5fdc PG |
982 | |
983 | There is no specific mailing list for Perl on VOS. You can post | |
984 | comments to the comp.sys.stratus newsgroup, or subscribe to the general | |
985 | Stratus mailing list. Send a letter with "Subscribe Info-Stratus" in | |
986 | the message body to majordomo@list.stratagy.com. | |
987 | ||
c997b287 GS |
988 | =item * |
989 | ||
990 | VOS Perl on the web at http://ftp.stratus.com/pub/vos/vos.html | |
495c5fdc PG |
991 | |
992 | =back | |
993 | ||
e41182b5 GS |
994 | =head2 EBCDIC Platforms |
995 | ||
996 | Recent versions of Perl have been ported to platforms such as OS/400 on | |
d1e3b762 GS |
997 | AS/400 minicomputers as well as OS/390, VM/ESA, and BS2000 for S/390 |
998 | Mainframes. Such computers use EBCDIC character sets internally (usually | |
0cc436d0 GS |
999 | Character Code Set ID 0037 for OS/400 and either 1047 or POSIX-BC for S/390 |
1000 | systems). On the mainframe perl currently works under the "Unix system | |
1001 | services for OS/390" (formerly known as OpenEdition), VM/ESA OpenEdition, or | |
1002 | the BS200 POSIX-BC system (BS2000 is supported in perl 5.6 and greater). | |
c997b287 | 1003 | See L<perlos390> for details. |
e41182b5 | 1004 | |
7c5ffed3 JH |
1005 | As of R2.5 of USS for OS/390 and Version 2.3 of VM/ESA these Unix |
1006 | sub-systems do not support the C<#!> shebang trick for script invocation. | |
1007 | Hence, on OS/390 and VM/ESA perl scripts can be executed with a header | |
1008 | similar to the following simple script: | |
e41182b5 GS |
1009 | |
1010 | : # use perl | |
1011 | eval 'exec /usr/local/bin/perl -S $0 ${1+"$@"}' | |
1012 | if 0; | |
1013 | #!/usr/local/bin/perl # just a comment really | |
1014 | ||
1015 | print "Hello from perl!\n"; | |
1016 | ||
d1e3b762 GS |
1017 | OS/390 will support the C<#!> shebang trick in release 2.8 and beyond. |
1018 | Calls to C<system> and backticks can use POSIX shell syntax on all | |
1019 | S/390 systems. | |
1020 | ||
b7df3edc | 1021 | On the AS/400, if PERL5 is in your library list, you may need |
6ab3f9cb GS |
1022 | to wrap your perl scripts in a CL procedure to invoke them like so: |
1023 | ||
1024 | BEGIN | |
1025 | CALL PGM(PERL5/PERL) PARM('/QOpenSys/hello.pl') | |
1026 | ENDPGM | |
1027 | ||
1028 | This will invoke the perl script F<hello.pl> in the root of the | |
1029 | QOpenSys file system. On the AS/400 calls to C<system> or backticks | |
1030 | must use CL syntax. | |
1031 | ||
e41182b5 | 1032 | On these platforms, bear in mind that the EBCDIC character set may have |
0a47030a GS |
1033 | an effect on what happens with some perl functions (such as C<chr>, |
1034 | C<pack>, C<print>, C<printf>, C<ord>, C<sort>, C<sprintf>, C<unpack>), as | |
1035 | well as bit-fiddling with ASCII constants using operators like C<^>, C<&> | |
1036 | and C<|>, not to mention dealing with socket interfaces to ASCII computers | |
6ab3f9cb | 1037 | (see L<"Newlines">). |
e41182b5 | 1038 | |
b7df3edc GS |
1039 | Fortunately, most web servers for the mainframe will correctly |
1040 | translate the C<\n> in the following statement to its ASCII equivalent | |
1041 | (C<\r> is the same under both Unix and OS/390 & VM/ESA): | |
e41182b5 GS |
1042 | |
1043 | print "Content-type: text/html\r\n\r\n"; | |
1044 | ||
d1e3b762 | 1045 | The values of C<$^O> on some of these platforms includes: |
e41182b5 | 1046 | |
d1e3b762 GS |
1047 | uname $^O $Config{'archname'} |
1048 | -------------------------------------------- | |
1049 | OS/390 os390 os390 | |
1050 | OS400 os400 os400 | |
1051 | POSIX-BC posix-bc BS2000-posix-bc | |
1052 | VM/ESA vmesa vmesa | |
3c075c7d | 1053 | |
e41182b5 GS |
1054 | Some simple tricks for determining if you are running on an EBCDIC |
1055 | platform could include any of the following (perhaps all): | |
1056 | ||
1057 | if ("\t" eq "\05") { print "EBCDIC may be spoken here!\n"; } | |
1058 | ||
1059 | if (ord('A') == 193) { print "EBCDIC may be spoken here!\n"; } | |
1060 | ||
1061 | if (chr(169) eq 'z') { print "EBCDIC may be spoken here!\n"; } | |
1062 | ||
b7df3edc | 1063 | One thing you may not want to rely on is the EBCDIC encoding |
0a47030a GS |
1064 | of punctuation characters since these may differ from code page to code |
1065 | page (and once your module or script is rumoured to work with EBCDIC, | |
1066 | folks will want it to work with all EBCDIC character sets). | |
e41182b5 GS |
1067 | |
1068 | Also see: | |
1069 | ||
1070 | =over 4 | |
1071 | ||
c997b287 GS |
1072 | =item * |
1073 | ||
1074 | * | |
d1e3b762 | 1075 | |
dc5c060f | 1076 | L<perlos390>, F<README.os390>, F<perlbs2000>, F<README.vmesa>, |
bb462878 | 1077 | L<perlebcdic>. |
c997b287 GS |
1078 | |
1079 | =item * | |
e41182b5 GS |
1080 | |
1081 | The perl-mvs@perl.org list is for discussion of porting issues as well as | |
1082 | general usage issues for all EBCDIC Perls. Send a message body of | |
1083 | "subscribe perl-mvs" to majordomo@perl.org. | |
1084 | ||
c997b287 GS |
1085 | =item * |
1086 | ||
1087 | AS/400 Perl information at | |
b1866b2d | 1088 | http://as400.rochester.ibm.com/ |
d1e3b762 | 1089 | as well as on CPAN in the F<ports/> directory. |
e41182b5 GS |
1090 | |
1091 | =back | |
1092 | ||
b8099c3d CN |
1093 | =head2 Acorn RISC OS |
1094 | ||
b7df3edc GS |
1095 | Because Acorns use ASCII with newlines (C<\n>) in text files as C<\012> like |
1096 | Unix, and because Unix filename emulation is turned on by default, | |
1097 | most simple scripts will probably work "out of the box". The native | |
6ab3f9cb | 1098 | filesystem is modular, and individual filesystems are free to be |
0a47030a | 1099 | case-sensitive or insensitive, and are usually case-preserving. Some |
b7df3edc | 1100 | native filesystems have name length limits, which file and directory |
6ab3f9cb GS |
1101 | names are silently truncated to fit. Scripts should be aware that the |
1102 | standard filesystem currently has a name length limit of B<10> | |
1103 | characters, with up to 77 items in a directory, but other filesystems | |
0a47030a | 1104 | may not impose such limitations. |
b8099c3d CN |
1105 | |
1106 | Native filenames are of the form | |
1107 | ||
6ab3f9cb | 1108 | Filesystem#Special_Field::DiskName.$.Directory.Directory.File |
dd9f0070 | 1109 | |
b8099c3d CN |
1110 | where |
1111 | ||
1112 | Special_Field is not usually present, but may contain . and $ . | |
1113 | Filesystem =~ m|[A-Za-z0-9_]| | |
1114 | DsicName =~ m|[A-Za-z0-9_/]| | |
1115 | $ represents the root directory | |
1116 | . is the path separator | |
1117 | @ is the current directory (per filesystem but machine global) | |
1118 | ^ is the parent directory | |
1119 | Directory and File =~ m|[^\0- "\.\$\%\&:\@\\^\|\177]+| | |
1120 | ||
1121 | The default filename translation is roughly C<tr|/.|./|;> | |
1122 | ||
6ab3f9cb | 1123 | Note that C<"ADFS::HardDisk.$.File" ne 'ADFS::HardDisk.$.File'> and that |
0a47030a GS |
1124 | the second stage of C<$> interpolation in regular expressions will fall |
1125 | foul of the C<$.> if scripts are not careful. | |
1126 | ||
1127 | Logical paths specified by system variables containing comma-separated | |
b7df3edc | 1128 | search lists are also allowed; hence C<System:Modules> is a valid |
0a47030a | 1129 | filename, and the filesystem will prefix C<Modules> with each section of |
6ab3f9cb | 1130 | C<System$Path> until a name is made that points to an object on disk. |
b7df3edc | 1131 | Writing to a new file C<System:Modules> would be allowed only if |
0a47030a GS |
1132 | C<System$Path> contains a single item list. The filesystem will also |
1133 | expand system variables in filenames if enclosed in angle brackets, so | |
c47ff5f1 | 1134 | C<< <System$Dir>.Modules >> would look for the file |
0a47030a | 1135 | S<C<$ENV{'System$Dir'} . 'Modules'>>. The obvious implication of this is |
c47ff5f1 | 1136 | that B<fully qualified filenames can start with C<< <> >>> and should |
0a47030a | 1137 | be protected when C<open> is used for input. |
b8099c3d CN |
1138 | |
1139 | Because C<.> was in use as a directory separator and filenames could not | |
1140 | be assumed to be unique after 10 characters, Acorn implemented the C | |
1141 | compiler to strip the trailing C<.c> C<.h> C<.s> and C<.o> suffix from | |
1142 | filenames specified in source code and store the respective files in | |
b7df3edc | 1143 | subdirectories named after the suffix. Hence files are translated: |
b8099c3d CN |
1144 | |
1145 | foo.h h.foo | |
1146 | C:foo.h C:h.foo (logical path variable) | |
1147 | sys/os.h sys.h.os (C compiler groks Unix-speak) | |
1148 | 10charname.c c.10charname | |
1149 | 10charname.o o.10charname | |
1150 | 11charname_.c c.11charname (assuming filesystem truncates at 10) | |
1151 | ||
1152 | The Unix emulation library's translation of filenames to native assumes | |
b7df3edc GS |
1153 | that this sort of translation is required, and it allows a user-defined list |
1154 | of known suffixes that it will transpose in this fashion. This may | |
1155 | seem transparent, but consider that with these rules C<foo/bar/baz.h> | |
0a47030a GS |
1156 | and C<foo/bar/h/baz> both map to C<foo.bar.h.baz>, and that C<readdir> and |
1157 | C<glob> cannot and do not attempt to emulate the reverse mapping. Other | |
6ab3f9cb | 1158 | C<.>'s in filenames are translated to C</>. |
0a47030a | 1159 | |
b7df3edc | 1160 | As implied above, the environment accessed through C<%ENV> is global, and |
0a47030a | 1161 | the convention is that program specific environment variables are of the |
6ab3f9cb GS |
1162 | form C<Program$Name>. Each filesystem maintains a current directory, |
1163 | and the current filesystem's current directory is the B<global> current | |
b7df3edc GS |
1164 | directory. Consequently, sociable programs don't change the current |
1165 | directory but rely on full pathnames, and programs (and Makefiles) cannot | |
0a47030a GS |
1166 | assume that they can spawn a child process which can change the current |
1167 | directory without affecting its parent (and everyone else for that | |
1168 | matter). | |
1169 | ||
b7df3edc GS |
1170 | Because native operating system filehandles are global and are currently |
1171 | allocated down from 255, with 0 being a reserved value, the Unix emulation | |
0a47030a GS |
1172 | library emulates Unix filehandles. Consequently, you can't rely on |
1173 | passing C<STDIN>, C<STDOUT>, or C<STDERR> to your children. | |
1174 | ||
1175 | The desire of users to express filenames of the form | |
c47ff5f1 | 1176 | C<< <Foo$Dir>.Bar >> on the command line unquoted causes problems, |
0a47030a | 1177 | too: C<``> command output capture has to perform a guessing game. It |
c47ff5f1 | 1178 | assumes that a string C<< <[^<>]+\$[^<>]> >> is a |
0a47030a | 1179 | reference to an environment variable, whereas anything else involving |
c47ff5f1 | 1180 | C<< < >> or C<< > >> is redirection, and generally manages to be 99% |
0a47030a GS |
1181 | right. Of course, the problem remains that scripts cannot rely on any |
1182 | Unix tools being available, or that any tools found have Unix-like command | |
1183 | line arguments. | |
1184 | ||
b7df3edc GS |
1185 | Extensions and XS are, in theory, buildable by anyone using free |
1186 | tools. In practice, many don't, as users of the Acorn platform are | |
1187 | used to binary distributions. MakeMaker does run, but no available | |
1188 | make currently copes with MakeMaker's makefiles; even if and when | |
1189 | this should be fixed, the lack of a Unix-like shell will cause | |
1190 | problems with makefile rules, especially lines of the form C<cd | |
1191 | sdbm && make all>, and anything using quoting. | |
b8099c3d CN |
1192 | |
1193 | "S<RISC OS>" is the proper name for the operating system, but the value | |
1194 | in C<$^O> is "riscos" (because we don't like shouting). | |
1195 | ||
e41182b5 GS |
1196 | =head2 Other perls |
1197 | ||
b7df3edc GS |
1198 | Perl has been ported to many platforms that do not fit into any of |
1199 | the categories listed above. Some, such as AmigaOS, Atari MiNT, | |
1200 | BeOS, HP MPE/iX, QNX, Plan 9, and VOS, have been well-integrated | |
1201 | into the standard Perl source code kit. You may need to see the | |
1202 | F<ports/> directory on CPAN for information, and possibly binaries, | |
1203 | for the likes of: aos, Atari ST, lynxos, riscos, Novell Netware, | |
1204 | Tandem Guardian, I<etc.> (Yes, we know that some of these OSes may | |
1205 | fall under the Unix category, but we are not a standards body.) | |
e41182b5 | 1206 | |
d1e3b762 GS |
1207 | Some approximate operating system names and their C<$^O> values |
1208 | in the "OTHER" category include: | |
1209 | ||
1210 | OS $^O $Config{'archname'} | |
1211 | ------------------------------------------ | |
1212 | Amiga DOS amigaos m68k-amigos | |
1213 | MPE/iX mpeix PA-RISC1.1 | |
1214 | ||
e41182b5 GS |
1215 | See also: |
1216 | ||
1217 | =over 4 | |
1218 | ||
c997b287 GS |
1219 | =item * |
1220 | ||
1221 | Amiga, F<README.amiga> (installed as L<perlamiga>). | |
1222 | ||
1223 | =item * | |
d1e3b762 | 1224 | |
c997b287 GS |
1225 | Atari, F<README.mint> and Guido Flohr's web page |
1226 | http://stud.uni-sb.de/~gufl0000/ | |
e41182b5 | 1227 | |
c997b287 | 1228 | =item * |
d1e3b762 | 1229 | |
c997b287 | 1230 | Be OS, F<README.beos> |
e41182b5 | 1231 | |
c997b287 GS |
1232 | =item * |
1233 | ||
1234 | HP 300 MPE/iX, F<README.mpeix> and Mark Bixby's web page | |
34aaaa84 | 1235 | http://www.bixby.org/mark/perlix.html |
c997b287 GS |
1236 | |
1237 | =item * | |
e41182b5 | 1238 | |
6ab3f9cb | 1239 | A free perl5-based PERL.NLM for Novell Netware is available in |
c997b287 | 1240 | precompiled binary and source code form from http://www.novell.com/ |
6ab3f9cb | 1241 | as well as from CPAN. |
e41182b5 | 1242 | |
13a2d996 | 1243 | =item * |
c997b287 GS |
1244 | |
1245 | Plan 9, F<README.plan9> | |
d1e3b762 | 1246 | |
e41182b5 GS |
1247 | =back |
1248 | ||
e41182b5 GS |
1249 | =head1 FUNCTION IMPLEMENTATIONS |
1250 | ||
b7df3edc GS |
1251 | Listed below are functions that are either completely unimplemented |
1252 | or else have been implemented differently on various platforms. | |
1253 | Following each description will be, in parentheses, a list of | |
1254 | platforms that the description applies to. | |
e41182b5 | 1255 | |
b7df3edc GS |
1256 | The list may well be incomplete, or even wrong in some places. When |
1257 | in doubt, consult the platform-specific README files in the Perl | |
1258 | source distribution, and any other documentation resources accompanying | |
1259 | a given port. | |
e41182b5 | 1260 | |
0a47030a | 1261 | Be aware, moreover, that even among Unix-ish systems there are variations. |
e41182b5 | 1262 | |
b7df3edc GS |
1263 | For many functions, you can also query C<%Config>, exported by |
1264 | default from the Config module. For example, to check whether the | |
1265 | platform has the C<lstat> call, check C<$Config{d_lstat}>. See | |
1266 | L<Config> for a full description of available variables. | |
e41182b5 GS |
1267 | |
1268 | =head2 Alphabetical Listing of Perl Functions | |
1269 | ||
1270 | =over 8 | |
1271 | ||
1272 | =item -X FILEHANDLE | |
1273 | ||
1274 | =item -X EXPR | |
1275 | ||
1276 | =item -X | |
1277 | ||
b7df3edc | 1278 | C<-r>, C<-w>, and C<-x> have a limited meaning only; directories |
e41182b5 | 1279 | and applications are executable, and there are no uid/gid |
b7df3edc | 1280 | considerations. C<-o> is not supported. (S<Mac OS>) |
e41182b5 | 1281 | |
b7df3edc GS |
1282 | C<-r>, C<-w>, C<-x>, and C<-o> tell whether the file is accessible, |
1283 | which may not reflect UIC-based file protections. (VMS) | |
e41182b5 | 1284 | |
b8099c3d CN |
1285 | C<-s> returns the size of the data fork, not the total size of data fork |
1286 | plus resource fork. (S<Mac OS>). | |
1287 | ||
1288 | C<-s> by name on an open file will return the space reserved on disk, | |
1289 | rather than the current extent. C<-s> on an open filehandle returns the | |
b7df3edc | 1290 | current size. (S<RISC OS>) |
b8099c3d | 1291 | |
e41182b5 | 1292 | C<-R>, C<-W>, C<-X>, C<-O> are indistinguishable from C<-r>, C<-w>, |
b8099c3d | 1293 | C<-x>, C<-o>. (S<Mac OS>, Win32, VMS, S<RISC OS>) |
e41182b5 GS |
1294 | |
1295 | C<-b>, C<-c>, C<-k>, C<-g>, C<-p>, C<-u>, C<-A> are not implemented. | |
1296 | (S<Mac OS>) | |
1297 | ||
1298 | C<-g>, C<-k>, C<-l>, C<-p>, C<-u>, C<-A> are not particularly meaningful. | |
b8099c3d | 1299 | (Win32, VMS, S<RISC OS>) |
e41182b5 GS |
1300 | |
1301 | C<-d> is true if passed a device spec without an explicit directory. | |
1302 | (VMS) | |
1303 | ||
1304 | C<-T> and C<-B> are implemented, but might misclassify Mac text files | |
0a47030a | 1305 | with foreign characters; this is the case will all platforms, but may |
b7df3edc | 1306 | affect S<Mac OS> often. (S<Mac OS>) |
e41182b5 GS |
1307 | |
1308 | C<-x> (or C<-X>) determine if a file ends in one of the executable | |
b7df3edc | 1309 | suffixes. C<-S> is meaningless. (Win32) |
e41182b5 | 1310 | |
b8099c3d CN |
1311 | C<-x> (or C<-X>) determine if a file has an executable file type. |
1312 | (S<RISC OS>) | |
1313 | ||
63f87e49 GS |
1314 | =item alarm SECONDS |
1315 | ||
1316 | =item alarm | |
1317 | ||
1318 | Not implemented. (Win32) | |
1319 | ||
e41182b5 GS |
1320 | =item binmode FILEHANDLE |
1321 | ||
b7df3edc | 1322 | Meaningless. (S<Mac OS>, S<RISC OS>) |
e41182b5 GS |
1323 | |
1324 | Reopens file and restores pointer; if function fails, underlying | |
1325 | filehandle may be closed, or pointer may be in a different position. | |
1326 | (VMS) | |
1327 | ||
1328 | The value returned by C<tell> may be affected after the call, and | |
1329 | the filehandle may be flushed. (Win32) | |
1330 | ||
1331 | =item chmod LIST | |
1332 | ||
b7df3edc | 1333 | Only limited meaning. Disabling/enabling write permission is mapped to |
e41182b5 GS |
1334 | locking/unlocking the file. (S<Mac OS>) |
1335 | ||
1336 | Only good for changing "owner" read-write access, "group", and "other" | |
1337 | bits are meaningless. (Win32) | |
1338 | ||
b8099c3d CN |
1339 | Only good for changing "owner" and "other" read-write access. (S<RISC OS>) |
1340 | ||
495c5fdc PG |
1341 | Access permissions are mapped onto VOS access-control list changes. (VOS) |
1342 | ||
e41182b5 GS |
1343 | =item chown LIST |
1344 | ||
495c5fdc | 1345 | Not implemented. (S<Mac OS>, Win32, Plan9, S<RISC OS>, VOS) |
e41182b5 GS |
1346 | |
1347 | Does nothing, but won't fail. (Win32) | |
1348 | ||
1349 | =item chroot FILENAME | |
1350 | ||
1351 | =item chroot | |
1352 | ||
7c5ffed3 | 1353 | Not implemented. (S<Mac OS>, Win32, VMS, Plan9, S<RISC OS>, VOS, VM/ESA) |
e41182b5 GS |
1354 | |
1355 | =item crypt PLAINTEXT,SALT | |
1356 | ||
1357 | May not be available if library or source was not provided when building | |
b8099c3d | 1358 | perl. (Win32) |
e41182b5 | 1359 | |
495c5fdc PG |
1360 | Not implemented. (VOS) |
1361 | ||
e41182b5 GS |
1362 | =item dbmclose HASH |
1363 | ||
495c5fdc | 1364 | Not implemented. (VMS, Plan9, VOS) |
e41182b5 GS |
1365 | |
1366 | =item dbmopen HASH,DBNAME,MODE | |
1367 | ||
495c5fdc | 1368 | Not implemented. (VMS, Plan9, VOS) |
e41182b5 GS |
1369 | |
1370 | =item dump LABEL | |
1371 | ||
b8099c3d | 1372 | Not useful. (S<Mac OS>, S<RISC OS>) |
e41182b5 GS |
1373 | |
1374 | Not implemented. (Win32) | |
1375 | ||
b8099c3d | 1376 | Invokes VMS debugger. (VMS) |
e41182b5 GS |
1377 | |
1378 | =item exec LIST | |
1379 | ||
1380 | Not implemented. (S<Mac OS>) | |
1381 | ||
7c5ffed3 | 1382 | Implemented via Spawn. (VM/ESA) |
3c075c7d | 1383 | |
0f897271 GS |
1384 | Does not automatically flush output handles on some platforms. |
1385 | (SunOS, Solaris, HP-UX) | |
1386 | ||
e41182b5 GS |
1387 | =item fcntl FILEHANDLE,FUNCTION,SCALAR |
1388 | ||
1389 | Not implemented. (Win32, VMS) | |
1390 | ||
1391 | =item flock FILEHANDLE,OPERATION | |
1392 | ||
495c5fdc | 1393 | Not implemented (S<Mac OS>, VMS, S<RISC OS>, VOS). |
e41182b5 GS |
1394 | |
1395 | Available only on Windows NT (not on Windows 95). (Win32) | |
1396 | ||
1397 | =item fork | |
1398 | ||
0f897271 GS |
1399 | Not implemented. (S<Mac OS>, AmigaOS, S<RISC OS>, VOS, VM/ESA) |
1400 | ||
1401 | Emulated using multiple interpreters. See L<perlfork>. (Win32) | |
1402 | ||
1403 | Does not automatically flush output handles on some platforms. | |
1404 | (SunOS, Solaris, HP-UX) | |
e41182b5 GS |
1405 | |
1406 | =item getlogin | |
1407 | ||
b8099c3d | 1408 | Not implemented. (S<Mac OS>, S<RISC OS>) |
e41182b5 GS |
1409 | |
1410 | =item getpgrp PID | |
1411 | ||
495c5fdc | 1412 | Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS) |
e41182b5 GS |
1413 | |
1414 | =item getppid | |
1415 | ||
b8099c3d | 1416 | Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>) |
e41182b5 GS |
1417 | |
1418 | =item getpriority WHICH,WHO | |
1419 | ||
7c5ffed3 | 1420 | Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS, VM/ESA) |
e41182b5 GS |
1421 | |
1422 | =item getpwnam NAME | |
1423 | ||
1424 | Not implemented. (S<Mac OS>, Win32) | |
1425 | ||
b8099c3d CN |
1426 | Not useful. (S<RISC OS>) |
1427 | ||
e41182b5 GS |
1428 | =item getgrnam NAME |
1429 | ||
b8099c3d | 1430 | Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>) |
e41182b5 GS |
1431 | |
1432 | =item getnetbyname NAME | |
1433 | ||
1434 | Not implemented. (S<Mac OS>, Win32, Plan9) | |
1435 | ||
1436 | =item getpwuid UID | |
1437 | ||
1438 | Not implemented. (S<Mac OS>, Win32) | |
1439 | ||
b8099c3d CN |
1440 | Not useful. (S<RISC OS>) |
1441 | ||
e41182b5 GS |
1442 | =item getgrgid GID |
1443 | ||
b8099c3d | 1444 | Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>) |
e41182b5 GS |
1445 | |
1446 | =item getnetbyaddr ADDR,ADDRTYPE | |
1447 | ||
1448 | Not implemented. (S<Mac OS>, Win32, Plan9) | |
1449 | ||
1450 | =item getprotobynumber NUMBER | |
1451 | ||
1452 | Not implemented. (S<Mac OS>) | |
1453 | ||
1454 | =item getservbyport PORT,PROTO | |
1455 | ||
1456 | Not implemented. (S<Mac OS>) | |
1457 | ||
1458 | =item getpwent | |
1459 | ||
7c5ffed3 | 1460 | Not implemented. (S<Mac OS>, Win32, VM/ESA) |
e41182b5 GS |
1461 | |
1462 | =item getgrent | |
1463 | ||
7c5ffed3 | 1464 | Not implemented. (S<Mac OS>, Win32, VMS, VM/ESA) |
e41182b5 GS |
1465 | |
1466 | =item gethostent | |
1467 | ||
1468 | Not implemented. (S<Mac OS>, Win32) | |
1469 | ||
1470 | =item getnetent | |
1471 | ||
1472 | Not implemented. (S<Mac OS>, Win32, Plan9) | |
1473 | ||
1474 | =item getprotoent | |
1475 | ||
1476 | Not implemented. (S<Mac OS>, Win32, Plan9) | |
1477 | ||
1478 | =item getservent | |
1479 | ||
1480 | Not implemented. (Win32, Plan9) | |
1481 | ||
1482 | =item setpwent | |
1483 | ||
b8099c3d | 1484 | Not implemented. (S<Mac OS>, Win32, S<RISC OS>) |
e41182b5 GS |
1485 | |
1486 | =item setgrent | |
1487 | ||
b8099c3d | 1488 | Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>) |
e41182b5 GS |
1489 | |
1490 | =item sethostent STAYOPEN | |
1491 | ||
b8099c3d | 1492 | Not implemented. (S<Mac OS>, Win32, Plan9, S<RISC OS>) |
e41182b5 GS |
1493 | |
1494 | =item setnetent STAYOPEN | |
1495 | ||
b8099c3d | 1496 | Not implemented. (S<Mac OS>, Win32, Plan9, S<RISC OS>) |
e41182b5 GS |
1497 | |
1498 | =item setprotoent STAYOPEN | |
1499 | ||
b8099c3d | 1500 | Not implemented. (S<Mac OS>, Win32, Plan9, S<RISC OS>) |
e41182b5 GS |
1501 | |
1502 | =item setservent STAYOPEN | |
1503 | ||
b8099c3d | 1504 | Not implemented. (Plan9, Win32, S<RISC OS>) |
e41182b5 GS |
1505 | |
1506 | =item endpwent | |
1507 | ||
a3dfe201 | 1508 | Not implemented. (S<Mac OS>, MPE/iX, VM/ESA, Win32) |
e41182b5 GS |
1509 | |
1510 | =item endgrent | |
1511 | ||
a3dfe201 | 1512 | Not implemented. (S<Mac OS>, MPE/iX, S<RISC OS>, VM/ESA, VMS, Win32) |
e41182b5 GS |
1513 | |
1514 | =item endhostent | |
1515 | ||
1516 | Not implemented. (S<Mac OS>, Win32) | |
1517 | ||
1518 | =item endnetent | |
1519 | ||
1520 | Not implemented. (S<Mac OS>, Win32, Plan9) | |
1521 | ||
1522 | =item endprotoent | |
1523 | ||
1524 | Not implemented. (S<Mac OS>, Win32, Plan9) | |
1525 | ||
1526 | =item endservent | |
1527 | ||
1528 | Not implemented. (Plan9, Win32) | |
1529 | ||
1530 | =item getsockopt SOCKET,LEVEL,OPTNAME | |
1531 | ||
1532 | Not implemented. (S<Mac OS>, Plan9) | |
1533 | ||
1534 | =item glob EXPR | |
1535 | ||
1536 | =item glob | |
1537 | ||
63f87e49 GS |
1538 | This operator is implemented via the File::Glob extension on most |
1539 | platforms. See L<File::Glob> for portability information. | |
b8099c3d | 1540 | |
e41182b5 GS |
1541 | =item ioctl FILEHANDLE,FUNCTION,SCALAR |
1542 | ||
1543 | Not implemented. (VMS) | |
1544 | ||
1545 | Available only for socket handles, and it does what the ioctlsocket() call | |
1546 | in the Winsock API does. (Win32) | |
1547 | ||
b8099c3d CN |
1548 | Available only for socket handles. (S<RISC OS>) |
1549 | ||
b350dd2f | 1550 | =item kill SIGNAL, LIST |
e41182b5 | 1551 | |
862b5365 JH |
1552 | C<kill(0, LIST)> is implemented for the sake of taint checking; |
1553 | use with other signals is unimplemented. (S<Mac OS>) | |
1554 | ||
1555 | Not implemented, hence not useful for taint checking. (S<RISC OS>) | |
e41182b5 | 1556 | |
63f87e49 GS |
1557 | C<kill()> doesn't have the semantics of C<raise()>, i.e. it doesn't send |
1558 | a signal to the identified process like it does on Unix platforms. | |
1559 | Instead C<kill($sig, $pid)> terminates the process identified by $pid, | |
1560 | and makes it exit immediately with exit status $sig. As in Unix, if | |
1561 | $sig is 0 and the specified process exists, it returns true without | |
1562 | actually terminating it. (Win32) | |
e41182b5 GS |
1563 | |
1564 | =item link OLDFILE,NEWFILE | |
1565 | ||
a3dfe201 | 1566 | Not implemented. (S<Mac OS>, MPE/iX, VMS, S<RISC OS>) |
e41182b5 | 1567 | |
433acd8a JH |
1568 | Link count not updated because hard links are not quite that hard |
1569 | (They are sort of half-way between hard and soft links). (AmigaOS) | |
1570 | ||
a3dfe201 GS |
1571 | Hard links are implemented on Win32 (Windows NT and Windows 2000) |
1572 | under NTFS only. | |
1573 | ||
e41182b5 GS |
1574 | =item lstat FILEHANDLE |
1575 | ||
1576 | =item lstat EXPR | |
1577 | ||
1578 | =item lstat | |
1579 | ||
b8099c3d | 1580 | Not implemented. (VMS, S<RISC OS>) |
e41182b5 | 1581 | |
63f87e49 | 1582 | Return values (especially for device and inode) may be bogus. (Win32) |
e41182b5 GS |
1583 | |
1584 | =item msgctl ID,CMD,ARG | |
1585 | ||
1586 | =item msgget KEY,FLAGS | |
1587 | ||
1588 | =item msgsnd ID,MSG,FLAGS | |
1589 | ||
1590 | =item msgrcv ID,VAR,SIZE,TYPE,FLAGS | |
1591 | ||
495c5fdc | 1592 | Not implemented. (S<Mac OS>, Win32, VMS, Plan9, S<RISC OS>, VOS) |
e41182b5 GS |
1593 | |
1594 | =item open FILEHANDLE,EXPR | |
1595 | ||
1596 | =item open FILEHANDLE | |
1597 | ||
b7df3edc | 1598 | The C<|> variants are supported only if ToolServer is installed. |
e41182b5 GS |
1599 | (S<Mac OS>) |
1600 | ||
c47ff5f1 | 1601 | open to C<|-> and C<-|> are unsupported. (S<Mac OS>, Win32, S<RISC OS>) |
e41182b5 | 1602 | |
0f897271 GS |
1603 | Opening a process does not automatically flush output handles on some |
1604 | platforms. (SunOS, Solaris, HP-UX) | |
1605 | ||
e41182b5 GS |
1606 | =item pipe READHANDLE,WRITEHANDLE |
1607 | ||
433acd8a JH |
1608 | Very limited functionality. (MiNT) |
1609 | ||
e41182b5 GS |
1610 | =item readlink EXPR |
1611 | ||
1612 | =item readlink | |
1613 | ||
b8099c3d | 1614 | Not implemented. (Win32, VMS, S<RISC OS>) |
e41182b5 GS |
1615 | |
1616 | =item select RBITS,WBITS,EBITS,TIMEOUT | |
1617 | ||
1618 | Only implemented on sockets. (Win32) | |
1619 | ||
b8099c3d CN |
1620 | Only reliable on sockets. (S<RISC OS>) |
1621 | ||
63f87e49 GS |
1622 | Note that the C<socket FILEHANDLE> form is generally portable. |
1623 | ||
e41182b5 GS |
1624 | =item semctl ID,SEMNUM,CMD,ARG |
1625 | ||
1626 | =item semget KEY,NSEMS,FLAGS | |
1627 | ||
1628 | =item semop KEY,OPSTRING | |
1629 | ||
495c5fdc | 1630 | Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS) |
e41182b5 | 1631 | |
a3dfe201 GS |
1632 | =item setgrent |
1633 | ||
1634 | Not implemented. (MPE/iX, Win32) | |
1635 | ||
e41182b5 GS |
1636 | =item setpgrp PID,PGRP |
1637 | ||
495c5fdc | 1638 | Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS) |
e41182b5 GS |
1639 | |
1640 | =item setpriority WHICH,WHO,PRIORITY | |
1641 | ||
495c5fdc | 1642 | Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS) |
e41182b5 | 1643 | |
a3dfe201 GS |
1644 | =item setpwent |
1645 | ||
1646 | Not implemented. (MPE/iX, Win32) | |
1647 | ||
e41182b5 GS |
1648 | =item setsockopt SOCKET,LEVEL,OPTNAME,OPTVAL |
1649 | ||
1650 | Not implemented. (S<Mac OS>, Plan9) | |
1651 | ||
1652 | =item shmctl ID,CMD,ARG | |
1653 | ||
1654 | =item shmget KEY,SIZE,FLAGS | |
1655 | ||
1656 | =item shmread ID,VAR,POS,SIZE | |
1657 | ||
1658 | =item shmwrite ID,STRING,POS,SIZE | |
1659 | ||
495c5fdc | 1660 | Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS) |
e41182b5 | 1661 | |
80cbd5ad JH |
1662 | =item sockatmark SOCKET |
1663 | ||
1664 | A relatively recent addition to socket functions, may not | |
1665 | be implemented even in UNIX platforms. | |
1666 | ||
e41182b5 GS |
1667 | =item socketpair SOCKET1,SOCKET2,DOMAIN,TYPE,PROTOCOL |
1668 | ||
862b5365 | 1669 | Not implemented. (Win32, VMS, S<RISC OS>, VOS, VM/ESA) |
e41182b5 GS |
1670 | |
1671 | =item stat FILEHANDLE | |
1672 | ||
1673 | =item stat EXPR | |
1674 | ||
1675 | =item stat | |
1676 | ||
d62e1b7f JH |
1677 | Platforms that do not have rdev, blksize, or blocks will return these |
1678 | as '', so numeric comparison or manipulation of these fields may cause | |
1679 | 'not numeric' warnings. | |
1680 | ||
e41182b5 GS |
1681 | mtime and atime are the same thing, and ctime is creation time instead of |
1682 | inode change time. (S<Mac OS>) | |
1683 | ||
1684 | device and inode are not meaningful. (Win32) | |
1685 | ||
1686 | device and inode are not necessarily reliable. (VMS) | |
1687 | ||
b8099c3d CN |
1688 | mtime, atime and ctime all return the last modification time. Device and |
1689 | inode are not necessarily reliable. (S<RISC OS>) | |
1690 | ||
d62e1b7f JH |
1691 | dev, rdev, blksize, and blocks are not available. inode is not |
1692 | meaningful and will differ between stat calls on the same file. (os2) | |
1693 | ||
e41182b5 GS |
1694 | =item symlink OLDFILE,NEWFILE |
1695 | ||
b8099c3d | 1696 | Not implemented. (Win32, VMS, S<RISC OS>) |
e41182b5 GS |
1697 | |
1698 | =item syscall LIST | |
1699 | ||
7c5ffed3 | 1700 | Not implemented. (S<Mac OS>, Win32, VMS, S<RISC OS>, VOS, VM/ESA) |
e41182b5 | 1701 | |
f34d0673 GS |
1702 | =item sysopen FILEHANDLE,FILENAME,MODE,PERMS |
1703 | ||
dd9f0070 | 1704 | The traditional "0", "1", and "2" MODEs are implemented with different |
322422de GS |
1705 | numeric values on some systems. The flags exported by C<Fcntl> |
1706 | (O_RDONLY, O_WRONLY, O_RDWR) should work everywhere though. (S<Mac | |
7c5ffed3 | 1707 | OS>, OS/390, VM/ESA) |
f34d0673 | 1708 | |
e41182b5 GS |
1709 | =item system LIST |
1710 | ||
1711 | Only implemented if ToolServer is installed. (S<Mac OS>) | |
1712 | ||
1713 | As an optimization, may not call the command shell specified in | |
b7df3edc | 1714 | C<$ENV{PERL5SHELL}>. C<system(1, @args)> spawns an external |
e41182b5 GS |
1715 | process and immediately returns its process designator, without |
1716 | waiting for it to terminate. Return value may be used subsequently | |
63f87e49 GS |
1717 | in C<wait> or C<waitpid>. Failure to spawn() a subprocess is indicated |
1718 | by setting $? to "255 << 8". C<$?> is set in a way compatible with | |
1719 | Unix (i.e. the exitstatus of the subprocess is obtained by "$? >> 8", | |
1720 | as described in the documentation). (Win32) | |
e41182b5 | 1721 | |
b8099c3d CN |
1722 | There is no shell to process metacharacters, and the native standard is |
1723 | to pass a command line terminated by "\n" "\r" or "\0" to the spawned | |
c47ff5f1 | 1724 | program. Redirection such as C<< > foo >> is performed (if at all) by |
b8099c3d CN |
1725 | the run time library of the spawned program. C<system> I<list> will call |
1726 | the Unix emulation library's C<exec> emulation, which attempts to provide | |
1727 | emulation of the stdin, stdout, stderr in force in the parent, providing | |
1728 | the child program uses a compatible version of the emulation library. | |
1729 | I<scalar> will call the native command line direct and no such emulation | |
1730 | of a child Unix program will exists. Mileage B<will> vary. (S<RISC OS>) | |
1731 | ||
433acd8a JH |
1732 | Far from being POSIX compliant. Because there may be no underlying |
1733 | /bin/sh tries to work around the problem by forking and execing the | |
9b63e9ec | 1734 | first token in its argument string. Handles basic redirection |
c47ff5f1 | 1735 | ("<" or ">") on its own behalf. (MiNT) |
433acd8a | 1736 | |
0f897271 GS |
1737 | Does not automatically flush output handles on some platforms. |
1738 | (SunOS, Solaris, HP-UX) | |
1739 | ||
e41182b5 GS |
1740 | =item times |
1741 | ||
1742 | Only the first entry returned is nonzero. (S<Mac OS>) | |
1743 | ||
63f87e49 GS |
1744 | "cumulative" times will be bogus. On anything other than Windows NT |
1745 | or Windows 2000, "system" time will be bogus, and "user" time is | |
1746 | actually the time returned by the clock() function in the C runtime | |
1747 | library. (Win32) | |
e41182b5 | 1748 | |
b8099c3d CN |
1749 | Not useful. (S<RISC OS>) |
1750 | ||
e41182b5 GS |
1751 | =item truncate FILEHANDLE,LENGTH |
1752 | ||
1753 | =item truncate EXPR,LENGTH | |
1754 | ||
6d738113 | 1755 | Not implemented. (Older versions of VMS) |
e41182b5 | 1756 | |
495c5fdc PG |
1757 | Truncation to zero-length only. (VOS) |
1758 | ||
4cfdb94f | 1759 | If a FILEHANDLE is supplied, it must be writable and opened in append |
e71a7dc8 | 1760 | mode (i.e., use C<<< open(FH, '>>filename') >>> |
4cfdb94f GS |
1761 | or C<sysopen(FH,...,O_APPEND|O_RDWR)>. If a filename is supplied, it |
1762 | should not be held open elsewhere. (Win32) | |
1763 | ||
e41182b5 GS |
1764 | =item umask EXPR |
1765 | ||
1766 | =item umask | |
1767 | ||
1768 | Returns undef where unavailable, as of version 5.005. | |
1769 | ||
b7df3edc GS |
1770 | C<umask> works but the correct permissions are set only when the file |
1771 | is finally closed. (AmigaOS) | |
433acd8a | 1772 | |
e41182b5 GS |
1773 | =item utime LIST |
1774 | ||
b8099c3d | 1775 | Only the modification time is updated. (S<Mac OS>, VMS, S<RISC OS>) |
e41182b5 | 1776 | |
322422de GS |
1777 | May not behave as expected. Behavior depends on the C runtime |
1778 | library's implementation of utime(), and the filesystem being | |
1779 | used. The FAT filesystem typically does not support an "access | |
1780 | time" field, and it may limit timestamps to a granularity of | |
1781 | two seconds. (Win32) | |
e41182b5 GS |
1782 | |
1783 | =item wait | |
1784 | ||
1785 | =item waitpid PID,FLAGS | |
1786 | ||
495c5fdc | 1787 | Not implemented. (S<Mac OS>, VOS) |
e41182b5 GS |
1788 | |
1789 | Can only be applied to process handles returned for processes spawned | |
a6f858fb | 1790 | using C<system(1, ...)> or pseudo processes created with C<fork()>. (Win32) |
e41182b5 | 1791 | |
b8099c3d CN |
1792 | Not useful. (S<RISC OS>) |
1793 | ||
e41182b5 GS |
1794 | =back |
1795 | ||
b8099c3d CN |
1796 | =head1 CHANGES |
1797 | ||
1798 | =over 4 | |
1799 | ||
fd46a41b JH |
1800 | =item v1.48, 02 February 2001 |
1801 | ||
1802 | Various updates from perl5-porters over the past year, supported | |
1803 | platforms update from Jarkko Hietaniemi. | |
1804 | ||
c997b287 GS |
1805 | =item v1.47, 22 March 2000 |
1806 | ||
1807 | Various cleanups from Tom Christiansen, including migration of | |
1808 | long platform listings from L<perl>. | |
1809 | ||
56d7751a GS |
1810 | =item v1.46, 12 February 2000 |
1811 | ||
1812 | Updates for VOS and MPE/iX. (Peter Prymmer) Other small changes. | |
1813 | ||
0cc436d0 GS |
1814 | =item v1.45, 20 December 1999 |
1815 | ||
1816 | Small changes from 5.005_63 distribution, more changes to EBCDIC info. | |
1817 | ||
d1e3b762 GS |
1818 | =item v1.44, 19 July 1999 |
1819 | ||
1820 | A bunch of updates from Peter Prymmer for C<$^O> values, | |
1821 | endianness, File::Spec, VMS, BS2000, OS/400. | |
1822 | ||
b7df3edc GS |
1823 | =item v1.43, 24 May 1999 |
1824 | ||
1825 | Added a lot of cleaning up from Tom Christiansen. | |
1826 | ||
19799a22 | 1827 | =item v1.42, 22 May 1999 |
b7df3edc | 1828 | |
19799a22 | 1829 | Added notes about tests, sprintf/printf, and epoch offsets. |
b7df3edc | 1830 | |
6ab3f9cb GS |
1831 | =item v1.41, 19 May 1999 |
1832 | ||
1833 | Lots more little changes to formatting and content. | |
1834 | ||
d1e3b762 | 1835 | Added a bunch of C<$^O> and related values |
6ab3f9cb GS |
1836 | for various platforms; fixed mail and web addresses, and added |
1837 | and changed miscellaneous notes. (Peter Prymmer) | |
1838 | ||
1839 | =item v1.40, 11 April 1999 | |
1840 | ||
1841 | Miscellaneous changes. | |
1842 | ||
1843 | =item v1.39, 11 February 1999 | |
2ee0eb3c CN |
1844 | |
1845 | Changes from Jarkko and EMX URL fixes Michael Schwern. Additional | |
1846 | note about newlines added. | |
1847 | ||
9b63e9ec CN |
1848 | =item v1.38, 31 December 1998 |
1849 | ||
1850 | More changes from Jarkko. | |
1851 | ||
3c075c7d CN |
1852 | =item v1.37, 19 December 1998 |
1853 | ||
1854 | More minor changes. Merge two separate version 1.35 documents. | |
1855 | ||
1856 | =item v1.36, 9 September 1998 | |
1857 | ||
1858 | Updated for Stratus VOS. Also known as version 1.35. | |
1859 | ||
1860 | =item v1.35, 13 August 1998 | |
495c5fdc | 1861 | |
3c075c7d CN |
1862 | Integrate more minor changes, plus addition of new sections under |
1863 | L<"ISSUES">: L<"Numbers endianness and Width">, | |
1864 | L<"Character sets and character encoding">, | |
1865 | L<"Internationalisation">. | |
495c5fdc | 1866 | |
3c075c7d | 1867 | =item v1.33, 06 August 1998 |
0a47030a GS |
1868 | |
1869 | Integrate more minor changes. | |
1870 | ||
3c075c7d | 1871 | =item v1.32, 05 August 1998 |
dd9f0070 CN |
1872 | |
1873 | Integrate more minor changes. | |
1874 | ||
3c075c7d | 1875 | =item v1.30, 03 August 1998 |
b8099c3d CN |
1876 | |
1877 | Major update for RISC OS, other minor changes. | |
1878 | ||
3c075c7d | 1879 | =item v1.23, 10 July 1998 |
b8099c3d CN |
1880 | |
1881 | First public release with perl5.005. | |
1882 | ||
1883 | =back | |
e41182b5 | 1884 | |
ba58ab26 JH |
1885 | =head1 Supported Platforms |
1886 | ||
9ca74005 JH |
1887 | As of early 2001 (the Perl releases 5.6.1 and 5.7.1), the following |
1888 | platforms are able to build Perl from the standard source code | |
1889 | distribution available at http://www.perl.com/CPAN/src/index.html | |
ba58ab26 JH |
1890 | |
1891 | AIX | |
fd46a41b | 1892 | AmigaOS |
b787fad4 | 1893 | Darwin (Mac OS X) |
fd46a41b | 1894 | DG/UX |
ba58ab26 | 1895 | DOS DJGPP 1) |
fd46a41b | 1896 | DYNIX/ptx |
6ba81f13 | 1897 | EPOC |
ba58ab26 JH |
1898 | FreeBSD |
1899 | HP-UX | |
1900 | IRIX | |
1901 | Linux | |
ba58ab26 | 1902 | MachTen |
fd46a41b JH |
1903 | MacOS Classic 2) |
1904 | NonStop-UX | |
1905 | ReliantUNIX (SINIX) | |
ba58ab26 | 1906 | OpenBSD |
fd46a41b | 1907 | OpenVMS (VMS) |
ba58ab26 | 1908 | OS/2 |
fd46a41b | 1909 | OS X |
ba58ab26 | 1910 | QNX |
ba58ab26 | 1911 | Solaris |
fd46a41b | 1912 | Tru64 UNIX (DEC OSF/1, Digital UNIX) |
ba58ab26 JH |
1913 | UNICOS |
1914 | UNICOS/mk | |
ba58ab26 | 1915 | VOS |
fd46a41b | 1916 | Win32/NT/2K 3) |
ba58ab26 JH |
1917 | |
1918 | 1) in DOS mode either the DOS or OS/2 ports can be used | |
fd46a41b JH |
1919 | 2) Mac OS Classic (pre-X) is almost 5.6.1-ready; building from |
1920 | the source does work with 5.6.1, but additional MacOS specific | |
862b5365 JH |
1921 | source code is needed for a complete build. See the web |
1922 | site http://dev.macperl.org/ for more information. | |
fd46a41b | 1923 | 3) compilers: Borland, Cygwin, Mingw32 EGCS/GCC, VC++ |
ba58ab26 | 1924 | |
9ca74005 JH |
1925 | The following platforms worked for the previous releases (5.6.0 and 5.7.0), |
1926 | but we did not manage to test these in time for the 5.7.1 release. | |
1927 | There is a very good chance that these will work fine with the 5.7.1. | |
ba58ab26 | 1928 | |
ba58ab26 JH |
1929 | DomainOS |
1930 | Hurd | |
fd46a41b JH |
1931 | LynxOS |
1932 | MinGW | |
1933 | MPE/iX | |
1934 | NetBSD | |
ba58ab26 | 1935 | PowerMAX |
fd46a41b | 1936 | SCO SV |
ba58ab26 | 1937 | SunOS |
fd46a41b JH |
1938 | SVR4 |
1939 | Unixware | |
1940 | Windows 3.1 | |
1941 | Windows 95 | |
1942 | Windows 98 | |
1943 | Windows Me | |
ba58ab26 | 1944 | |
fd46a41b | 1945 | The following platform worked for the 5.005_03 major release but not |
9ca74005 JH |
1946 | for 5.6.0. Standardization on UTF-8 as the internal string |
1947 | representation in 5.6.0 and 5.6.1 introduced incompatibilities in this | |
1948 | EBCDIC platform. While Perl 5.7.1 will build on this platform some | |
fd46a41b | 1949 | regression tests may fail and the C<use utf8;> pragma typically |
9ca74005 | 1950 | introduces text handling errors. |
ba58ab26 | 1951 | |
fd46a41b | 1952 | OS/390 1) |
ba58ab26 | 1953 | |
fd46a41b | 1954 | 1) previously known as MVS, about to become z/OS. |
ba58ab26 | 1955 | |
fd46a41b | 1956 | Strongly related to the OS/390 platform by also being EBCDIC-based |
ba58ab26 JH |
1957 | mainframe platforms are the following platforms: |
1958 | ||
fd46a41b | 1959 | POSIX-BC (BS2000) |
ba58ab26 JH |
1960 | VM/ESA |
1961 | ||
fd46a41b JH |
1962 | These are also expected to work, albeit with no UTF-8 support, under 5.6.1 |
1963 | for the same reasons as OS/390. Contact the mailing list perl-mvs@perl.org | |
1964 | for more details. | |
ba58ab26 JH |
1965 | |
1966 | The following platforms have been known to build Perl from source in | |
fd46a41b JH |
1967 | the past (5.005_03 and earlier), but we haven't been able to verify |
1968 | their status for the current release, either because the | |
1969 | hardware/software platforms are rare or because we don't have an | |
1970 | active champion on these platforms--or both. They used to work, | |
1971 | though, so go ahead and try compiling them, and let perlbug@perl.org | |
1972 | of any trouble. | |
ba58ab26 JH |
1973 | |
1974 | 3b1 | |
fd46a41b JH |
1975 | A/UX |
1976 | BeOS | |
1977 | BSD/OS | |
ba58ab26 JH |
1978 | ConvexOS |
1979 | CX/UX | |
1980 | DC/OSx | |
1981 | DDE SMES | |
1982 | DOS EMX | |
1983 | Dynix | |
1984 | EP/IX | |
1985 | ESIX | |
1986 | FPS | |
1987 | GENIX | |
1988 | Greenhills | |
1989 | ISC | |
1990 | MachTen 68k | |
1991 | MiNT | |
1992 | MPC | |
1993 | NEWS-OS | |
fd46a41b JH |
1994 | NextSTEP |
1995 | OpenSTEP | |
ba58ab26 JH |
1996 | Opus |
1997 | Plan 9 | |
1998 | PowerUX | |
1999 | RISC/os | |
fd46a41b | 2000 | SCO ODT/OSR |
ba58ab26 JH |
2001 | Stellar |
2002 | SVR2 | |
2003 | TI1500 | |
2004 | TitanOS | |
fd46a41b | 2005 | Ultrix |
ba58ab26 JH |
2006 | Unisys Dynix |
2007 | Unixware | |
fd46a41b | 2008 | UTS |
ba58ab26 JH |
2009 | |
2010 | Support for the following platform is planned for a future Perl release: | |
2011 | ||
2012 | Netware | |
2013 | ||
2014 | The following platforms have their own source code distributions and | |
2015 | binaries available via http://www.perl.com/CPAN/ports/index.html: | |
2016 | ||
2017 | Perl release | |
2018 | ||
ba58ab26 | 2019 | Netware 5.003_07 |
fd46a41b | 2020 | OS/400 5.005_02 |
ba58ab26 JH |
2021 | Tandem Guardian 5.004 |
2022 | ||
2023 | The following platforms have only binaries available via | |
c997b287 | 2024 | http://www.perl.com/CPAN/ports/index.html : |
ba58ab26 JH |
2025 | |
2026 | Perl release | |
2027 | ||
2028 | Acorn RISCOS 5.005_02 | |
2029 | AOS 5.002 | |
2030 | LynxOS 5.004_02 | |
2031 | ||
2032 | Although we do suggest that you always build your own Perl from | |
2033 | the source code, both for maximal configurability and for security, | |
2034 | in case you are in a hurry you can check | |
2035 | http://www.perl.com/CPAN/ports/index.html for binary distributions. | |
2036 | ||
c997b287 GS |
2037 | =head1 SEE ALSO |
2038 | ||
a83b6f46 | 2039 | L<perlaix>, L<perlapollo>, L<perlamiga>, L<perlbeos>, L<perlbs200>, |
a1f19229 | 2040 | L<perlce>, L<perlcygwin>, L<perldgux>, L<perldos>, L<perlepoc>, L<perlebcdic>, |
a83b6f46 | 2041 | L<perlhurd>, L<perlhpux>, L<perlmachten>, L<perlmacos>, L<perlmint>, |
9038e305 JH |
2042 | L<perlmpeix>, L<perlnetware>, L<perlos2>, L<perlos390>, L<perlplan9>, |
2043 | L<perlqnx>, L<perlsolaris>, L<perltru64>, L<perlunicode>, | |
2044 | L<perlvmesa>, L<perlvms>, L<perlvos>, L<perlwin32>, and L<Win32>. | |
c997b287 | 2045 | |
e41182b5 GS |
2046 | =head1 AUTHORS / CONTRIBUTORS |
2047 | ||
06e9666b | 2048 | Abigail <abigail@foad.org>, |
c47ff5f1 GS |
2049 | Charles Bailey <bailey@newman.upenn.edu>, |
2050 | Graham Barr <gbarr@pobox.com>, | |
2051 | Tom Christiansen <tchrist@perl.com>, | |
06e9666b | 2052 | Nicholas Clark <nick@ccl4.org>, |
c47ff5f1 | 2053 | Thomas Dorner <Thomas.Dorner@start.de>, |
06e9666b A |
2054 | Andy Dougherty <doughera@lafayette.edu>, |
2055 | Dominic Dunlop <domo@computer.org>, | |
2056 | Neale Ferguson <neale@vma.tabnsw.com.au>, | |
c47ff5f1 GS |
2057 | David J. Fiander <davidf@mks.com>, |
2058 | Paul Green <Paul_Green@stratus.com>, | |
06e9666b | 2059 | M.J.T. Guy <mjtg@cam.ac.uk>, |
61f30a5e | 2060 | Jarkko Hietaniemi <jhi@iki.fi>, |
c47ff5f1 | 2061 | Luther Huffman <lutherh@stratcom.com>, |
06e9666b A |
2062 | Nick Ing-Simmons <nick@ing-simmons.net>, |
2063 | Andreas J. KE<ouml>nig <a.koenig@mind.de>, | |
c47ff5f1 GS |
2064 | Markus Laker <mlaker@contax.co.uk>, |
2065 | Andrew M. Langmead <aml@world.std.com>, | |
2066 | Larry Moore <ljmoore@freespace.net>, | |
2067 | Paul Moore <Paul.Moore@uk.origin-it.com>, | |
2068 | Chris Nandor <pudge@pobox.com>, | |
2069 | Matthias Neeracher <neeri@iis.ee.ethz.ch>, | |
e71a7dc8 | 2070 | Philip Newton <pne@cpan.org>, |
c47ff5f1 GS |
2071 | Gary Ng <71564.1743@CompuServe.COM>, |
2072 | Tom Phoenix <rootbeer@teleport.com>, | |
2073 | AndrE<eacute> Pirard <A.Pirard@ulg.ac.be>, | |
2074 | Peter Prymmer <pvhp@forte.com>, | |
2075 | Hugo van der Sanden <hv@crypt0.demon.co.uk>, | |
2076 | Gurusamy Sarathy <gsar@activestate.com>, | |
2077 | Paul J. Schinder <schinder@pobox.com>, | |
2078 | Michael G Schwern <schwern@pobox.com>, | |
06e9666b | 2079 | Dan Sugalski <dan@sidhe.org>, |
c47ff5f1 | 2080 | Nathan Torkington <gnat@frii.com>. |
e41182b5 | 2081 | |
e41182b5 GS |
2082 | =head1 VERSION |
2083 | ||
b787fad4 | 2084 | Version 1.50, last modified 10 Jul 2001 |