/ strGT(s1,s2)
strncmp(s1, s2, n) strnNE(s1, s2, n) / strnEQ(s1, s2, n)
+ memcmp(p1, p2, n) memNE(p1, p2, n)
+ !memcmp(p1, p2, n) memEQ(p1, p2, n)
+
Notice the different order of arguments to C<Copy> and C<Move> than used
in C<memcpy> and C<memmove>.
=head2 Character Class Tests
-There are two types of character class tests that Perl implements: one
-type deals in C<char>s and are thus B<not> Unicode aware (and hence
-deprecated unless you B<know> you should use them) and the other type
-deal in C<UV>s and know about Unicode properties. In the following
-table, C<c> is a C<char>, and C<u> is a Unicode codepoint.
-
- Instead Of: Use: But better use:
-
- isalnum(c) isALNUM(c) isALNUM_uni(u)
- isalpha(c) isALPHA(c) isALPHA_uni(u)
- iscntrl(c) isCNTRL(c) isCNTRL_uni(u)
- isdigit(c) isDIGIT(c) isDIGIT_uni(u)
- isgraph(c) isGRAPH(c) isGRAPH_uni(u)
- islower(c) isLOWER(c) isLOWER_uni(u)
- isprint(c) isPRINT(c) isPRINT_uni(u)
- ispunct(c) isPUNCT(c) isPUNCT_uni(u)
- isspace(c) isSPACE(c) isSPACE_uni(u)
- isupper(c) isUPPER(c) isUPPER_uni(u)
- isxdigit(c) isXDIGIT(c) isXDIGIT_uni(u)
-
- tolower(c) toLOWER(c) toLOWER_uni(u)
- toupper(c) toUPPER(c) toUPPER_uni(u)
+There are several types of character class tests that Perl implements.
+The only ones described here are those that directly correspond to C
+library functions that operate on 8-bit characters, but there are
+equivalents that operate on wide characters, and UTF-8 encoded strings.
+All are more fully described in L<perlapi/Character classification> and
+L<perlapi/Character case changing>.
+
+The C library routines listed in the table below return values based on
+the current locale. Use the entries in the final column for that
+functionality. The other two columns always assume a POSIX (or C)
+locale. The entries in the ASCII column are only meaningful for ASCII
+inputs, returning FALSE for anything else. Use these only when you
+B<know> that is what you want. The entries in the Latin1 column assume
+that the non-ASCII 8-bit characters are as Unicode defines, them, the
+same as ISO-8859-1, often called Latin 1.
+
+ Instead Of: Use for ASCII: Use for Latin1: Use for locale:
+
+ isalnum(c) isALPHANUMERIC(c) isALPHANUMERIC_L1(c) isALPHANUMERIC_LC(c)
+ isalpha(c) isALPHA(c) isALPHA_L1(c) isALPHA_LC(u )
+ isascii(c) isASCII(c) isASCII_LC(c)
+ isblank(c) isBLANK(c) isBLANK_L1(c) isBLANK_LC(c)
+ iscntrl(c) isCNTRL(c) isCNTRL_L1(c) isCNTRL_LC(c)
+ isdigit(c) isDIGIT(c) isDIGIT_L1(c) isDIGIT_LC(c)
+ isgraph(c) isGRAPH(c) isGRAPH_L1(c) isGRAPH_LC(c)
+ islower(c) isLOWER(c) isLOWER_L1(c) isLOWER_LC(c)
+ isprint(c) isPRINT(c) isPRINT_L1(c) isPRINT_LC(c)
+ ispunct(c) isPUNCT(c) isPUNCT_L1(c) isPUNCT_LC(c)
+ isspace(c) isSPACE(c) isSPACE_L1(c) isSPACE_LC(c)
+ isupper(c) isUPPER(c) isUPPER_L1(c) isUPPER_LC(c)
+ isxdigit(c) isXDIGIT(c) isXDIGIT_L1(c) isXDIGIT_LC(c)
+
+ tolower(c) toLOWER(c) toLOWER_L1(c) toLOWER_LC(c)
+ toupper(c) toUPPER(c) toUPPER_LC(c)
+
+To emphasize that you are operating only on ASCII characters, you can
+append C<_A> to each of the macros in the ASCII column: C<isALPHA_A>,
+C<isDIGIT_A>, and so on.
+
+(There is no entry in the Latin1 column for C<isascii> even though there
+is an C<isASCII_L1>, which is identical to C<isASCII>; the
+latter name is clearer. There is no entry in the Latin1 column for
+C<toupper> because the result can be non-Latin1. You have to use
+C<toUPPER_uni>, as described in L<perlapi/Character case changing>.)
=head2 F<stdlib.h> functions
Instead Of: Use:
atof(s) Atof(s)
- atol(s) Atol(s)
+ atoi(s) grok_atoUV(s, &uv, &e)
+ atol(s) grok_atoUV(s, &uv, &e)
strtod(s, &p) Nothing. Just don't use it.
- strtol(s, &p, n) Strtol(s, &p, n)
- strtoul(s, &p, n) Strtoul(s, &p, n)
+ strtol(s, &p, n) grok_atoUV(s, &uv, &e)
+ strtoul(s, &p, n) grok_atoUV(s, &uv, &e)
+
+Typical use is to do range checks on C<uv> before casting:
+
+ int i; UV uv; char* end_ptr;
+ if (grok_atoUV(input, &uv, &end_ptr)
+ && uv <= INT_MAX)
+ i = (int)uv;
+ ... /* continue parsing from end_ptr */
+ } else {
+ ... /* parse error: not a decimal integer in range 0 .. MAX_IV */
+ }
Notice also the C<grok_bin>, C<grok_hex>, and C<grok_oct> functions in
F<numeric.c> for converting strings representing numbers in the respective
-bases into C<NV>s.
+bases into C<NV>s. Note that grok_atoUV() doesn't handle negative inputs,
+or leading whitespace (being purposefully strict).
+
+Note that strtol() and strtoul() may be disguised as Strtol(), Strtoul(),
+Atol(), Atoul(). Avoid those, too.
In theory C<Strtol> and C<Strtoul> may not be defined if the machine perl is
built on doesn't actually have strtol and strtoul. But as those 2
PL_srand_called = TRUE; }
exit(n) my_exit(n)
- system(s) Don't. Look at pp_system or use my_popen
+ system(s) Don't. Look at pp_system or use my_popen.
getenv(s) PerlEnv_getenv(s)
- setenv(s, val) my_putenv(s, val)
+ setenv(s, val) my_setenv(s, val)
=head2 Miscellaneous functions
https://perl5.git.perl.org / perl5.git / blobdiff