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Annotated edit history of perlclib(1) version 2, including all changes. View license author blame.
Rev Author # Line
1 perry 1 PERLCLIB
2 !!!PERLCLIB
3 NAME
4 DESCRIPTION
5 SEE ALSO
6 ----
7 !!NAME
8
9
10 perlclib - Internal replacements for standard C library functions
11 !!DESCRIPTION
12
13
14 One thing Perl porters should note is that ''perl''
15 doesn't tend to use that much of the C standard library
16 internally; you'll see very little use of, for example, the
17 ''ctype.h'' functions in there. This is because Perl
18 tends to reimplement or abstract standard library functions,
19 so that we know exactly how they're going to
20 operate.
21
22
23 This is a reference card for people who are familiar with
24 the C library and who want to do things the Perl way; to
25 tell them which functions they ought to use instead of the
26 more normal C functions.
27
28
29 __Conventions__
30
31
32 In the following tables:
33
34
35 t
36
37
38 is a type.
39
40
41 p
42
43
44 is a pointer.
45
46
47 n
48
49
50 is a number.
51
52
53 s
54
55
56 is a string.
57
58
59 sv, av, hv, etc. represent
60 variables of their respective types.
61
62
63 __File Operations__
64
65
66 Instead of the ''stdio.h'' functions, you should use the
67 Perl abstraction layer. Instead of FILE* types, you
68 need to be handling PerlIO* types. Don't forget
69 that with the new PerlIO layered I/O abstraction
70 FILE* types may not even be available. See also the
71 perlapio documentation for more information about
72 the following functions:
73
74
75 Instead Of: Use:
76 stdin PerlIO_stdin()
77 stdout PerlIO_stdout()
78 stderr PerlIO_stderr()
79 fopen(fn, mode) PerlIO_open(fn, mode)
80 freopen(fn, mode, stream) PerlIO_reopen(fn, mode, perlio) (Deprecated)
81 fflush(stream) PerlIO_flush(perlio)
82 fclose(stream) PerlIO_close(perlio)
83
84
85 __File Input and Output__
86
87
88 Instead Of: Use:
89 fprintf(stream, fmt, ...) PerlIO_printf(perlio, fmt, ...)
90 [[f]getc(stream) PerlIO_getc(perlio)
91 [[f]putc(stream, n) PerlIO_putc(perlio, n)
92 ungetc(n, stream) PerlIO_ungetc(perlio, n)
93 Note that the PerlIO equivalents of fread and fwrite are slightly different from their C library counterparts:
94
95
96 fread(p, size, n, stream) PerlIO_read(perlio, buf, numbytes)
97 fwrite(p, size, n, stream) PerlIO_write(perlio, buf, numbytes)
98 fputs(s, stream) PerlIO_puts(perlio, s)
99 There is no equivalent to fgets; one should use sv_gets instead:
100
101
102 fgets(s, n, stream) sv_gets(sv, perlio, append)
103
104
105 __File Positioning__
106
107
108 Instead Of: Use:
109 feof(stream) PerlIO_eof(perlio)
110 fseek(stream, n, whence) PerlIO_seek(perlio, n, whence)
111 rewind(stream) PerlIO_rewind(perlio)
112 fgetpos(stream, p) PerlIO_getpos(perlio, sv)
113 fsetpos(stream, p) PerlIO_setpos(perlio, sv)
114 ferror(stream) PerlIO_error(perlio)
115 clearerr(stream) PerlIO_clearerr(perlio)
116
117
118 __Memory Management and String Handling__
119
120
121 Instead Of: Use:
122 t* p = malloc(n) New(id, p, n, t)
123 t* p = calloc(n, s) Newz(id, p, n, t)
124 p = realloc(p, n) Renew(p, n, t)
125 memcpy(dst, src, n) Copy(src, dst, n, t)
126 memmove(dst, src, n) Move(src, dst, n, t)
2 perry 127 memcpy/*(struct foo *) !StructCopy(src, dst, t)
1 perry 128 free(p) Safefree(p)
129 strdup(p) savepv(p)
130 strndup(p, n) savepvn(p, n) (Hey, strndup doesn't exist!)
131 strstr(big, little) instr(big, little)
132 strcmp(s1, s2) strLE(s1, s2) / strEQ(s1, s2) / strGT(s1,s2)
133 strncmp(s1, s2, n) strnNE(s1, s2, n) / strnEQ(s1, s2, n)
134 Notice the different order of arguments to Copy and Move than used in memcpy and memmove.
135
136
137 Most of the time, though, you'll want to be dealing with SVs
138 internally instead of raw char *
139 strings:
140
141
142 strlen(s) sv_len(sv)
143 strcpy(dt, src) sv_setpv(sv, s)
144 strncpy(dt, src, n) sv_setpvn(sv, s, n)
145 strcat(dt, src) sv_catpv(sv, s)
146 strncat(dt, src) sv_catpvn(sv, s)
147 sprintf(s, fmt, ...) sv_setpvf(sv, fmt, ...)
148 Note also the existence of sv_catpvf and sv_catpvfn, combining concatenation with formatting.
149
150
151 __Character Class Tests__
152
153
154 There are two types of character class tests that Perl
155 implements: one type deals in chars and are thus
156 __not__ Unicode aware (and hence deprecated unless you
157 __know__ you should use them) and the other type deal in
158 UVs and know about Unicode properties. In the
159 following table, c is a char, and
160 u is a Unicode codepoint.
161
162
163 Instead Of: Use: But better use:
164 isalnum(c) isALNUM(c) isALNUM_uni(u)
165 isalpha(c) isALPHA(c) isALPHA_uni(u)
166 iscntrl(c) isCNTRL(c) isCNTRL_uni(u)
167 isdigit(c) isDIGIT(c) isDIGIT_uni(u)
168 isgraph(c) isGRAPH(c) isGRAPH_uni(u)
169 islower(c) isLOWER(c) isLOWER_uni(u)
170 isprint(c) isPRINT(c) isPRINT_uni(u)
171 ispunct(c) isPUNCT(c) isPUNCT_uni(u)
172 isspace(c) isSPACE(c) isSPACE_uni(u)
173 isupper(c) isUPPER(c) isUPPER_uni(u)
174 isxdigit(c) isXDIGIT(c) isXDIGIT_uni(u)
175 tolower(c) toLOWER(c) toLOWER_uni(u)
176 toupper(c) toUPPER(c) toUPPER_uni(u)
177
178
179 ''stdlib.h'' __functions__
180
181
182 Instead Of: Use:
183 atof(s) Atof(s)
184 atol(s) Atol(s)
185 strtod(s, *p) Nothing. Just don't use it.
186 strtol(s, *p, n) Strtol(s, *p, n)
187 strtoul(s, *p, n) Strtoul(s, *p, n)
188 Notice also the scan_bin, scan_hex, and scan_oct functions in ''util.c'' for converting strings representing numbers in the respective bases into NVs.
189
190
191 In theory Strtol and Strtoul may not be
192 defined if the machine perl is built on doesn't actually
193 have strtol and strtoul. But as those 2 functions are part
194 of the 1989 ANSI C spec we suspect you'll
195 find them everywhere by now.
196
197
198 int rand() double Drand01()
199 srand(n) { seedDrand01((Rand_seed_t)n);
200 PL_srand_called = TRUE; }
201 exit(n) my_exit(n)
202 system(s) Don't. Look at pp_system or use my_popen
2 perry 203 getenv(s) !PerlEnv_getenv(s)
1 perry 204 setenv(s, val) my_putenv(s, val)
205
206
207 __Miscellaneous functions__
208
209
210 You should not even __want__ to use ''setjmp.h''
211 functions, but if you think you do, use the JMPENV
212 stack in ''scope.h'' instead.
213
214
215 For signal/sigaction, use
216 rsignal(signo, handler).
217 !!SEE ALSO
218
219
220 perlapi, perlapio,
221 perlguts
222 ----
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