This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
Add hints for new users, and miscellaneous updates from Andy Dougherty
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1=head1 NAME
2
3Install - Build and Installation guide for perl5.
4
5=head1 SYNOPSIS
6
7The basic steps to build and install perl5 are:
8
9 rm -f config.sh
10 sh Configure
11 make
12 make test
13 make install
14
15Each of these is explained in further detail below.
16
edb1cbcb 17You should probably at least skim through this entire document before
18proceeding. Special notes specific to this release are identified
19by B<NOTE>.
20
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21=head1 BUILDING PERL5
22
23=head1 Start with a Fresh Distribution.
24
edb1cbcb 25If you have built perl before, you should clean out the build directory
26with the command
27
28 make realclean
29
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30The results of a Configure run are stored in the config.sh file. If
31you are upgrading from a previous version of perl, or if you change
32systems or compilers or make other significant changes, or if you are
33experiencing difficulties building perl, you should probably I<not>
34re-use your old config.sh. Simply remove it or rename it, e.g.
35
36 mv config.sh config.sh.old
4633a7c4 37
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38Then run Configure.
39
40=head1 Run Configure.
41
42Configure will figure out various things about your system. Some
43things Configure will figure out for itself, other things it will ask
44you about. To accept the default, just press C<RETURN>. The default
45is almost always ok.
46
47After it runs, Configure will perform variable substitution on all the
48F<*.SH> files and offer to run B<make depend>.
49
50Configure supports a number of useful options. Run B<Configure -h>
51to get a listing. To compile with gcc, for example, you can run
52
53 sh Configure -Dcc=gcc
54
55This is the preferred way to specify gcc (or another alternative
56compiler) so that the hints files can set appropriate defaults.
57
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58If you want to use your old config.sh but override some of the items
59with command line options, you need to use B<Configure -O>.
60
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61If you are willing to accept all the defaults, and you want terse
62output, you can run
63
64 sh Configure -des
65
66By default, for most systems, perl will be installed in
67/usr/local/{bin, lib, man}. You can specify a different 'prefix' for
68the default installation directory, when Configure prompts you or by
69using the Configure command line option -Dprefix='/some/directory',
70e.g.
71
25f94b33 72 sh Configure -Dprefix=/opt/perl
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73
74If your prefix contains the string "perl", then the directories
75are simplified. For example, if you use prefix=/opt/perl,
76then Configure will suggest /opt/perl/lib instead of
77/usr/local/lib/perl5/.
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78
79By default, Configure will compile perl to use dynamic loading, if
80your system supports it. If you want to force perl to be compiled
81statically, you can either choose this when Configure prompts you or by
82using the Configure command line option -Uusedl.
83
24b3df7f 84=head2 Extensions
85
edb1cbcb 86By default, Configure will offer to build every extension which appears
87to be supported. For example, Configure will offer to build GDBM_File
88only if it is able to find the gdbm library. (See examples below.)
89DynaLoader, Fcntl and FileHandle are always built by default.
90Configure does not contain code to test for POSIX compliance, so POSIX
91is always built by default as well. If you wish to skip POSIX, you can
92set the Configure variable useposix=false either in a hint file or from
93the Configure command line. Similarly, the Safe extension is always
94built by default, but you can skip it by setting the Configure variable
24b3df7f 95usesafe=false either in a hint file for from the command line.
96
97In summary, here are the Configure command-line variables you can set
98to turn off each extension:
99
100 DB_File i_db
101 DynaLoader (Must always be included)
102 Fcntl (Always included by default)
edb1cbcb 103 FileHandle (Always included by default)
24b3df7f 104 GDBM_File i_gdbm
105 NDBM_File i_ndbm
106 ODBM_File i_dbm
107 POSIX useposix
108 SDBM_File (Always included by default)
109 Safe usesafe
110 Socket d_socket
111
112Thus to skip the NDBM_File extension, you can use
113
114 sh Configure -Ui_ndbm
115
116Again, this is taken care of automatically if you don't have the ndbm
117library.
118
119Of course, you may always run Configure interactively and select only
120the Extensions you want.
121
122Finally, if you have dynamic loading (most modern Unix systems do)
123remember that these extensions do not increase the size of your perl
124executable, nor do they impact start-up time, so you probably might as
125well build all the ones that will work on your system.
126
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127=head2 GNU-style configure
128
129If you prefer the GNU-style B<configure> command line interface, you can
130use the supplied B<configure> command, e.g.
131
132 CC=gcc ./configure
133
134The B<configure> script emulates several of the more common configure
135options. Try
136
137 ./configure --help
138
139for a listing.
140
141Cross compiling is currently not supported.
142
143=head2 Including locally-installed libraries
144
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145Perl5 comes with interfaces to number of database extensions, including
146dbm, ndbm, gdbm, and Berkeley db. For each extension, if
147Configure can find the appropriate header files and libraries, it will
148automatically include that extension. The gdbm and db libraries
149are B<not> included with perl. See the library documentation for
150how to obtain the libraries.
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151
152I<Note:> If your database header (.h) files are not in a
153directory normally searched by your C compiler, then you will need to
154include the appropriate B<-I/your/directory> option when prompted by
155Configure. If your database library (.a) files are not in a directory
156normally searched by your C compiler and linker, then you will need to
157include the appropriate B<-L/your/directory> option when prompted by
158Configure. See the examples below.
159
160=head2 Examples
161
162=over 4
163
164=item gdbm in /usr/local.
165
166Suppose you have gdbm and want Configure to find it and build the
167GDBM_File extension. This examples assumes you have F<gdbm.h>
168installed in F</usr/local/include/gdbm.h> and F<libgdbm.a> installed in
169F</usr/local/lib/libgdbm.a>. Configure should figure all the
170necessary steps out automatically.
171
172Specifically, when Configure prompts you for flags for
173your C compiler, you should include C<-I/usr/local/include>.
174
175When Configure prompts you for linker flags, you should include
176C<-L/usr/local/lib>.
177
178If you are using dynamic loading, then when Configure prompts you for
179linker flags for dynamic loading, you should again include
180C<-L/usr/local/lib>.
181
182Again, this should all happen automatically. If you want to accept the
183defaults for all the questions and have Configure print out only terse
184messages, then you can just run
185
186 sh Configure -des
187
188and Configure should include the GDBM_File extension automatically.
189
190This should actually work if you have gdbm installed in any of
191(/usr/local, /opt/local, /usr/gnu, /opt/gnu, /usr/GNU, or /opt/GNU).
192
193=item gdbm in /usr/you
194
195Suppose you have gdbm installed in some place other than /usr/local/,
196but you still want Configure to find it. To be specific, assume you
197have F</usr/you/include/gdbm.h> and F</usr/you/lib/libgdbm.a>. You
198still have to add B<-I/usr/you/include> to cc flags, but you have to take
199an extra step to help Configure find F<libgdbm.a>. Specifically, when
200Configure prompts you for library directories, you have to add
201F</usr/you/lib> to the list.
202
203It is possible to specify this from the command line too (all on one
204line):
205
206 sh Configure -des \
207 -Dlocincpth="/usr/you/include" \
208 -Dloclibpth="/usr/you/lib"
209
210C<locincpth> is a space-separated list of include directories to search.
211Configure will automatically add the appropriate B<-I> directives.
212
213C<loclibpth> is a space-separated list of library directories to search.
214Configure will automatically add the appropriate B<-L> directives. If
215you have some libraries under F</usr/local/> and others under
216F</usr/you>, then you have to include both, namely
217
218 sh Configure -des \
219 -Dlocincpth="/usr/you/include /usr/local/include" \
220 -Dloclibpth="/usr/you/lib /usr/local/lib"
221
222=back
223
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224=head2 Installation Directories.
225
226The installation directories can all be changed by answering the
227appropriate questions in Configure. For convenience, all the
228installation questions are near the beginning of Configure.
229
230By default, Configure uses the following directories for
231library files (archname is a string like sun4-sunos, determined
232by Configure)
233
234 /usr/local/lib/perl5/archname/5.002
235 /usr/local/lib/perl5/
24b3df7f 236 /usr/local/lib/perl5/site_perl/archname
237 /usr/local/lib/perl5/site_perl
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238
239and the following directories for manual pages:
240
241 /usr/local/man/man1
242 /usr/local/lib/perl5/man/man3
243
244(Actually, Configure recognizes the SVR3-style
245/usr/local/man/l_man/man1 directories, if present, and uses those
246instead.) The module man pages are stuck in that strange spot so that
247they don't collide with other man pages stored in /usr/local/man/man3,
248and so that Perl's man pages don't hide system man pages. On some
249systems, B<man less> would end up calling up Perl's less.pm module man
250page, rather than the B<less> program.
251
252If you specify a prefix that contains the string "perl", then the
253directory structure is simplified. For example, if you Configure
254with -Dprefix=/opt/perl, then the defaults are
255
256 /opt/perl/lib/archname/5.002
257 /opt/perl/lib
258 /opt/perl/lib/site_perl/archname
259 /opt/perl/lib/site_perl
260
261 /opt/perl/man/man1
262 /opt/perl/man/man3
263
264The perl executable will search the libraries in the order given
265above.
266
267The directories site_perl and site_perl/archname are empty, but are
268intended to be used for installing local or site-wide extensions. Perl
269will automatically look in these directories. Previously, most sites
270just put their local extensions in with the standard distribution.
271
272In order to support using things like #!/usr/local/bin/perl5.002 after
273a later version is released, architecture-dependent libraries are
274stored in a version-specific directory, such as
275/usr/local/lib/perl5/archname/5.002/. In 5.000 and 5.001, these files
276were just stored in /usr/local/lib/perl5/archname/. If you will not be
277using 5.001 binaries, you can delete the standard extensions from the
278/usr/local/lib/perl5/archname/ directory. Locally-added extensions can
279be moved to the site_perl and site_perl/archname directories.
280
281Again, these are just the defaults, and can be changed as you run
282Configure.
283
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284=head2 Changing the installation directory
285
286Configure distinguishes between the directory in which perl (and its
287associated files) should be installed and the directory in which it
288will eventually reside. For most sites, these two are the same; for
289sites that use AFS, this distinction is handled automatically.
290However, sites that use software such as B<depot> to manage software
291packages may also wish to install perl into a different directory and
292use that management software to move perl to its final destination.
293This section describes how to do this. Someday, Configure may support
294an option C<-Dinstallprefix=/foo> to simplify this.
295
296Suppose you want to install perl under the F</tmp/perl5> directory.
297You can edit F<config.sh> and change all the install* variables to
298point to F</tmp/perl5> instead of F</usr/local/wherever>. You could
299also set them all from the Configure command line. Or, you can
300automate this process by placing the following lines in a file
301F<config.over> B<before> you run Configure (replace /tmp/perl5 by a
302directory of your choice):
303
304 installprefix=/tmp/perl5
305 test -d $installprefix || mkdir $installprefix
306 test -d $installprefix/bin || mkdir $installprefix/bin
307 installarchlib=`echo $installarchlib | sed "s!$prefix!$installprefix!"`
308 installbin=`echo $installbin | sed "s!$prefix!$installprefix!"`
309 installman1dir=`echo $installman1dir | sed "s!$prefix!$installprefix!"`
310 installman3dir=`echo $installman3dir | sed "s!$prefix!$installprefix!"`
311 installprivlib=`echo $installprivlib | sed "s!$prefix!$installprefix!"`
312 installscript=`echo $installscript | sed "s!$prefix!$installprefix!"`
313 installsitelib=`echo $installsitelib | sed "s!$prefix!$installprefix!"`
4633a7c4 314 installsitearch=`echo $installsitearch | sed "s!$prefix!$installprefix!"`
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315
316Then, you can Configure and install in the usual way:
317
25f94b33 318 sh Configure -des
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319 make
320 make test
321 make install
322
323=head2 Creating an installable tar archive
324
325If you need to install perl on many identical systems, it is
326convenient to compile it once and create an archive that can be
327installed on multiple systems. Here's one way to do that:
328
329 # Set up config.over to install perl into a different directory,
330 # e.g. /tmp/perl5 (see previous part).
25f94b33 331 sh Configure -des
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332 make
333 make test
334 make install
335 cd /tmp/perl5
336 tar cvf ../perl5-archive.tar .
337 # Then, on each machine where you want to install perl,
338 cd /usr/local # Or wherever you specified as $prefix
339 tar xvf perl5-archive.tar
340
341=head2 What if it doesn't work?
342
343=over 4
344
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345=item Running Configure Interactively
346
347If Configure runs into trouble, remember that you can always run
348Configure interactively so that you can check (and correct) its
349guesses.
350
351All the installation questions have been moved to the top, so you don't
352have to wait for them. Once you've handled them (and your C compiler &
353flags) you can type '&-d' at the next Configure prompt and Configure
354will use the defaults from then on.
355
356If you find yourself trying obscure command line incantations and
357config.over tricks, I recommend you run Configure interactively
358instead. You'll probably save yourself time in the long run.
359
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360=item Hint files.
361
362The perl distribution includes a number of system-specific hints files
363in the hints/ directory. If one of them matches your system, Configure
364will offer to use that hint file.
365
366Several of the hint files contain additional important information.
367If you have any problems, it is a good idea to read the relevant hint
368file for further information. See F<hints/solaris_2.sh> for an
369extensive example.
370
edb1cbcb 371=item *** WHOA THERE!!! ***
372
373Occasionally, Configure makes a wrong guess. For example, on SunOS
3744.1.3, Configure incorrectly concludes that tzname[] is in the
375standard C library. The hint file is set up to correct for this. You
376will see a message:
377
378 *** WHOA THERE!!! ***
379 The recommended value for $d_tzname on this machine was "undef"!
380 Keep the recommended value? [y]
381
382You should always keep the recommended value unless, after reading the
383relevant section of the hint file, you are sure you want to try
384overriding it.
385
386If you are re-using an old config.sh, the word "previous" will be
387used instead of "recommended". Again, you will almost always want
388to keep the previous value, unless you have changed something on your
389system.
390
391For example, suppose you have added libgdbm.a to your system
392and you decide to reconfigure perl to use GDBM_File. When you run
393Configure again, you will need to add -lgdbm to the list of libraries.
394Now, Configure will find your gdbm library and will issue a message:
395
396 *** WHOA THERE!!! ***
397 The previous value for $i_gdbm on this machine was "undef"!
398 Keep the previous value? [y]
399
400In this case, you do I<not> want to keep the previous value, so you
401should answer 'n'. (You'll also have to manuually add GDBM_File to
402the list of dynamic extensions to build.)
403
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404=item Changing Compilers
405
406If you change compilers or make other significant changes, you should
407probably I<not> re-use your old config.sh. Simply remove it or
408rename it, e.g. mv config.sh config.sh.old. Then rerun Configure
409with the options you want to use.
410
411This is a common source of problems. If you change from B<cc> to
412B<gcc>, you should almost always remove your old config.sh.
413
414=item Propagating your changes
415
416If you later make any changes to F<config.sh>, you should propagate
25f94b33 417them to all the .SH files by running B<sh Configure -S>.
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418
419=item config.over
420
421You can also supply a shell script config.over to over-ride Configure's
422guesses. It will get loaded up at the very end, just before config.sh
423is created. You have to be careful with this, however, as Configure
d52d4e46 424does no checking that your changes make sense. See the section on
425changing the installation directory for an example.
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426
427=item config.h
428
429Many of the system dependencies are contained in F<config.h>.
430F<Configure> builds F<config.h> by running the F<config_h.SH> script.
431The values for the variables are taken from F<config.sh>.
432
433If there are any problems, you can edit F<config.h> directly. Beware,
434though, that the next time you run B<Configure>, your changes will be
435lost.
436
437=item cflags
438
439If you have any additional changes to make to the C compiler command
440line, they can be made in F<cflags.SH>. For instance, to turn off the
441optimizer on F<toke.c>, find the line in the switch structure for
442F<toke.c> and put the command C<optimize='-g'> before the C<;;>. You
443can also edit F<cflags> directly, but beware that your changes will be
444lost the next time you run B<Configure>.
445
446To change the C flags for all the files, edit F<config.sh>
447and change either C<$ccflags> or C<$optimize>,
25f94b33 448and then re-run B<sh Configure -S ; make depend>.
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449
450=item No sh.
451
452If you don't have sh, you'll have to copy the sample file config_H to
453config.h and edit the config.h to reflect your system's peculiarities.
454You'll probably also have to extensively modify the extension building
455mechanism.
456
457=back
458
459=head1 make depend
460
461This will look for all the includes.
462The output is stored in F<makefile>. The only difference between
463F<Makefile> and F<makefile> is the dependencies at the bottom of
464F<makefile>. If you have to make any changes, you should edit
465F<makefile>, not F<Makefile> since the Unix B<make> command reads
4633a7c4 466F<makefile> first.
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467
468Configure will offer to do this step for you, so it isn't listed
469explicitly above.
470
471=head1 make
472
473This will attempt to make perl in the current directory.
474
475If you can't compile successfully, try some of the following ideas.
476
477=over 4
478
479=item *
480
481If you used a hint file, try reading the comments in the hint file
482for further tips and information.
483
484=item *
485
486If you can't compile successfully, try adding a C<-DCRIPPLED_CC> flag.
487(Just because you get no errors doesn't mean it compiled right!)
488This simplifies some complicated expressions for compilers that
489get indigestion easily. If that has no effect, try turning off
490optimization. If you have missing routines, you probably need to
491add some library or other, or you need to undefine some feature that
492Configure thought was there but is defective or incomplete.
493
494=item *
495
496Some compilers will not compile or optimize the larger files without
497some extra switches to use larger jump offsets or allocate larger
498internal tables. You can customize the switches for each file in
499F<cflags>. It's okay to insert rules for specific files into
500F<makefile> since a default rule only takes effect in the absence of a
501specific rule.
502
503=item *
504
505If you can successfully build F<miniperl>, but the process crashes
506during the building of extensions, you should run
507
508 make minitest
509
510to test your version of miniperl.
511
512=item *
513
514Some additional things that have been reported for either perl4 or perl5:
515
516Genix may need to use libc rather than libc_s, or #undef VARARGS.
517
518NCR Tower 32 (OS 2.01.01) may need -W2,-Sl,2000 and #undef MKDIR.
519
520UTS may need one or more of B<-DCRIPPLED_CC>, B<-K> or B<-g>, and undef LSTAT.
521
522If you get syntax errors on '(', try -DCRIPPLED_CC.
523
524Machines with half-implemented dbm routines will need to #undef I_ODBM
525
526SCO prior to 3.2.4 may be missing dbmclose(). An upgrade to 3.2.4
527that includes libdbm.nfs (which includes dbmclose()) may be available.
528
529If you get duplicates upon linking for malloc et al, say -DHIDEMYMALLOC.
530
531If you get duplicate function definitions (a perl function has the
532same name as another function on your system) try -DEMBED.
533
534If you get varags problems with gcc, be sure that gcc is installed
535correctly. When using gcc, you should probably have i_stdarg='define'
536and i_varags='undef' in config.sh. The problem is usually solved
537by running fixincludes correctly.
538
539If you wish to use dynamic loading on SunOS or Solaris, and you
540have GNU as and GNU ld installed, you may need to add B<-B/bin/> to
541your $ccflags and $ldflags so that the system's versions of as
542and ld are used.
543
544If you run into dynamic loading problems, check your setting of
545the LD_LIBRARY_PATH environment variable. Perl should build
546fine with LD_LIBRARY_PATH unset, though that may depend on details
547of your local set-up.
548
24b3df7f 549If Configure seems to be having trouble finding library functions,
550try not using nm extraction. You can do this from the command line
551with
552
553 sh Configure -Uusenm
554
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555=back
556
557=head1 make test
558
559This will run the regression tests on the perl you just made. If it
560doesn't say "All tests successful" then something went wrong. See the
561file F<t/README> in the F<t> subdirectory. Note that you can't run it
562in background if this disables opening of /dev/tty. If B<make test>
563bombs out, just B<cd> to the F<t> directory and run B<TEST> by hand
564to see if it makes any difference.
565If individual tests bomb, you can run them by hand, e.g.,
566
567 ./perl op/groups.t
568
edb1cbcb 569B<Note>: one possible reason for errors is that some external programs
c07a80fd 570may be broken due to the combination of your environment and the way
571C<make test> exercises them. This may happen for example if you have
572one or more of these environment variables set:
573C<LC_ALL LC_CTYPE LANG>. In certain UNIXes especially the non-English
574locales are known to cause programs to exhibit mysterious errors.
575If you have any of the above environment variables set, please try
576C<setenv LC_ALL C> or <LC_ALL=C;export LC_ALL>, for C<csh>-style and
577C<Bourne>-style shells, respectively, from the command line and then
578retry C<make test>. If the tests then succeed, you may have a broken
579program that is confusing the testing. Please run the troublesome test
580by hand as shown above and see whether you can locate the program.
581Look for things like:
582C<exec, `backquoted command`, system, open("|...")> or C<open("...|")>.
583All these mean that Perl is trying to run some external program.
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584=head1 INSTALLING PERL5
585
586=head1 make install
587
588This will put perl into the public directory you specified to
589B<Configure>; by default this is F</usr/local/bin>. It will also try
590to put the man pages in a reasonable place. It will not nroff the man
591page, however. You may need to be root to run B<make install>. If you
592are not root, you must own the directories in question and you should
593ignore any messages about chown not working.
594
edb1cbcb 595B<NOTE:> In the 5.002 release, you will see some harmless error
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596messages and warnings from pod2man. You may safely ignore them. (Yes,
597they should be fixed, but they didn't seem important enough to warrant
598holding up the entire 5.002 release.)
599
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600If you want to see exactly what will happen without installing
601anything, you can run
4633a7c4 602
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603 ./perl installperl -n
604 ./perl installman -n
605
606B<make install> will install the following:
607
608 perl,
609 perl5.nnn where nnn is the current release number. This
610 will be a link to perl.
611 suidperl,
612 sperl5.nnn If you requested setuid emulation.
613 a2p awk-to-perl translator
614 cppstdin This is used by perl -P, if your cc -E can't
615 read from stdin.
616 c2ph, pstruct Scripts for handling C structures in header files.
617 s2p sed-to-perl translator
618 find2perl find-to-perl translator
619 h2xs Converts C .h header files to Perl extensions.
24b3df7f 620 perlbug Tool to report bugs in Perl.
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621 perldoc Tool to read perl's pod documentation.
622 pod2html, Converters from perl's pod documentation format
623 pod2latex, and to other useful formats.
624 pod2man
625
626 library files in $privlib and $archlib specified to
627 Configure, usually under /usr/local/lib/perl5/.
628 man pages in the location specified to Configure, usually
629 something like /usr/local/man/man1.
630 module in the location specified to Configure, usually
631 man pages under /usr/local/lib/perl5/man/man3.
632 pod/*.pod in $privlib/pod/.
633
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634Installperl will also create the library directories $siteperl and
635$sitearch listed in config.sh. Usually, these are something like
24b3df7f 636 /usr/local/lib/perl5/site_perl/
637 /usr/local/lib/perl5/site_perl/$archname
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638where $archname is something like sun4-sunos. These directories
639will be used for installing extensions.
640
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641Perl's *.h header files and the libperl.a library are also
642installed under $archlib so that any user may later build new
643extensions even if the Perl source is no longer available.
644
645The libperl.a library is only needed for building new
646extensions and linking them statically into a new perl executable.
647If you will not be doing that, then you may safely delete
648$archlib/libperl.a after perl is installed.
649
650make install may also offer to install perl in a "standard" location.
651
652Most of the documentation in the pod/ directory is also available
653in HTML and LaTeX format. Type
654
655 cd pod; make html; cd ..
656
657to generate the html versions, and
658
659 cd pod; make tex; cd ..
660
661to generate the LaTeX versions.
662
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663=head1 Coexistence with earlier versions of perl5.
664
665You can safely install the current version of perl5 and still run
666scripts under the old binaries. Instead of starting your script with
667#!/usr/local/bin/perl, just start it with #!/usr/local/bin/perl5.001
668(or whatever version you want to run.)
669
670The architecture-dependent files are stored in a version-specific
671directory (such as F</usr/local/lib/perl5/sun4-sunos/5.002>) so that
672they are still accessible. I<Note:> perl5.000 and perl5.001 did not
673put their architecture-dependent libraries in a version-specific
674directory. They are simply in F</usr/local/lib/perl5/$archname>. If
675you will not be using 5.000 or 5.001, you may safely remove those
676files.
677
678The standard library files in F</usr/local/lib/perl5>
679should be useable by all versions of perl5.
680
d52d4e46 681Most extensions will probably not need to be recompiled to use with a newer
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682version of perl. If you do run into problems, and you want to continue
683to use the old version of perl along with your extension, simply move
684those extension files to the appropriate version directory, such as
685F</usr/local/lib/perl/archname/5.002>. Then perl5.002 will find your
686files in the 5.002 directory, and newer versions of perl will find your
687newer extension in the site_perl directory.
688
d52d4e46 689Some users may prefer to keep all versions of perl in completely
690separate directories. One convenient way to do this is by
691using a separate prefix for each version, such as
692
693 sh Configure -Dprefix=/opt/perl5.002
694
695and adding /opt/perl5.002/bin to the shell PATH variable. Such users
696may also wish to add a symbolic link /usr/local/bin/perl so that
697scripts can still start with #!/usr/local/bin/perl.
698
edb1cbcb 699B<NOTE>: Starting with 5.002_01, all functions in the perl C source
700code are protected by default by the prefix Perl_ (or perl_) so that
701you may link with third-party libraries without fear of namespace
702collisons. This breaks compatability with the initially released
703version of 5.002, so once you install 5.002_01 (or higher) you will
704need to re-build and install all of your dynamically loadable
705extensions. (The standard extensions supplied with Perl are handled
706automatically). You can turn off this namespace protection by adding
707-DNO_EMBED to your ccflags variable in config.sh. This is a one-time
708change. In the future, we certainly hope that most extensions won't
709need to be recompiled for use with a newer version of perl.
710
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711=head1 Coexistence with perl4
712
713You can safely install perl5 even if you want to keep perl4 around.
714
715By default, the perl5 libraries go into F</usr/local/lib/perl5/>, so
716they don't override the perl4 libraries in F</usr/local/lib/perl/>.
717
718In your /usr/local/bin directory, you should have a binary named
719F<perl4.036>. That will not be touched by the perl5 installation
720process. Most perl4 scripts should run just fine under perl5.
721However, if you have any scripts that require perl4, you can replace
722the C<#!> line at the top of them by C<#!/usr/local/bin/perl4.036>
edb1cbcb 723(or whatever the appropriate pathname is). See pod/perltrap.pod
724for possible problems running perl4 scripts under perl5.
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725
726=head1 DOCUMENTATION
727
728Read the manual entries before running perl. The main documentation is
729in the pod/ subdirectory and should have been installed during the
730build process. Type B<man perl> to get started. Alternatively, you
731can type B<perldoc perl> to use the supplied B<perldoc> script. This
732is sometimes useful for finding things in the library modules.
733
734=head1 AUTHOR
735
736Andy Dougherty <doughera@lafcol.lafayette.edu>, borrowing I<very> heavily
737from the original README by Larry Wall.
738
a5f75d66 739=head1 LAST MODIFIED
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edb1cbcb 74119 March 1996