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2 .\" Copyright 2014 Garrett D'Amore <garrett@damore.org>
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15 .TH STRING 3C "Jun 21, 2013"
16 .SH NAME
17 string, strcasecmp, strcasecmp_l, strncasecmp, strncasecmp_l, strcat, strncat,
18 strlcat, strchr, strrchr,
19 strcmp, strncmp, strcpy, strncpy, strlcpy, strcspn, strspn, strdup, strlen,
20 strnlen, strpbrk, strsep, strstr, strtok, strtok_r \- string operations
21 .SH SYNOPSIS
22 .LP
23 .nf
24 #include <strings.h>
25
26 \fBint\fR \fBstrcasecmp\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR);
27 .fi
28 .LP
29 .nf
30 \fBint\fR \fBstrcasecmp_l\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR, \fBlocale_t\fR \fIloc\fR);
31 .fi
32 .LP
33 .nf
34 \fBint\fR \fBstrncasecmp\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR, \fBsize_t\fR \fIn\fR);
35 .fi
36 .LP
37 .nf
38 \fBint\fR \fBstrncasecmp_l\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR, \fBsize_t\fR \fIn\fR, \fBlocale_t\fR \fIloc\fR);
39 .fi
40 .LP
41 .nf
42 #include <string.h>
43
44 \fBchar *\fR\fBstrcat\fR(\fBchar *restrict\fR \fIs1\fR, \fBconst char *restrict\fR \fIs2\fR);
45 .fi
46 .LP
47 .nf
48 \fBchar *\fR\fBstrncat\fR(\fBchar *restrict\fR \fIs1\fR, \fBconst char *restrict\fR \fIs2\fR, \fBsize_t\fR \fIn\fR);
49 .fi
50 .LP
51 .nf
52 \fBsize_t\fR \fBstrlcat\fR(\fBchar *\fR\fIdst\fR, \fBconst char *\fR\fIsrc\fR, \fBsize_t\fR \fIdstsize\fR);
53 .fi
54 .LP
55 .nf
56 \fBchar *\fR\fBstrchr\fR(\fBconst char *\fR\fIs\fR, \fBint\fR \fIc\fR);
57 .fi
58 .LP
59 .nf
60 \fBchar *\fR\fBstrrchr\fR(\fBconst char *\fR\fIs\fR, \fBint\fR \fIc\fR);
61 .fi
62 .LP
63 .nf
64 \fBint\fR \fBstrcmp\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR);
65 .fi
66 .LP
67 .nf
68 \fBint\fR \fBstrncmp\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR, \fBsize_t\fR \fIn\fR);
69 .fi
70 .LP
71 .nf
72 \fBchar *\fR\fBstrcpy\fR(\fBchar *restrict\fR \fIs1\fR, \fBconst char *restrict\fR \fIs2\fR);
73 .fi
74 .LP
75 .nf
76 \fBchar *\fR\fBstrncpy\fR(\fBchar *restrict\fR \fIs1\fR, \fBconst char *restrict\fR \fIs2\fR, \fBsize_t\fR \fIn\fR);
77 .fi
78 .LP
79 .nf
80 \fBsize_t\fR \fBstrlcpy\fR(\fBchar *\fR\fIdst\fR, \fBconst char *\fR\fIsrc\fR, \fBsize_t\fR \fIdstsize\fR);
81 .fi
82 .LP
83 .nf
84 \fBsize_t\fR \fBstrcspn\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR);
85 .fi
86 .LP
87 .nf
88 \fBsize_t\fR \fBstrspn\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR);
89 .fi
90 .LP
91 .nf
92 \fBchar *\fR\fBstrdup\fR(\fBconst char *\fR\fIs1\fR);
93 .fi
94 .LP
95 .nf
96 \fBsize_t\fR \fBstrlen\fR(\fBconst char *\fR\fIs\fR);
97 .fi
98 .LP
99 .nf
100 \fBsize_t\fR \fBstrnlen\fR(\fBconst char *\fR\fIs\fR, \fBsize_t\fR \fIn\fR);
101 .fi
102 .LP
103 .nf
104 \fBchar *\fR\fBstrpbrk\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR);
105 .fi
106 .LP
107 .nf
108 \fBchar *\fR\fBstrsep\fR(\fBchar **\fR\fIstringp\fR, \fBconst char *\fR\fIdelim\fR);
109 .fi
110 .LP
111 .nf
112 \fBchar *\fR\fBstrstr\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR);
113 .fi
114 .LP
115 .nf
116 \fBchar *\fR\fBstrtok\fR(\fBchar *restrict\fR \fIs1\fR, \fBconst char *restrict\fR \fIs2\fR);
117 .fi
118 .LP
119 .nf
120 \fBchar *\fR\fBstrtok_r\fR(\fBchar *restrict\fR \fIs1\fR, \fBconst char *restrict\fR \fIs2\fR,
121 \fBchar **restrict\fR \fIlasts\fR);
122 .fi
123 .SS "ISO C++"
124 .LP
125 .nf
126 #include <string.h>
127
128 \fBconst char *\fR\fBstrchr\fR(\fBconst char *\fR\fIs\fR, \fBint\fR \fIc\fR);
129 .fi
130 .LP
131 .nf
132 \fBconst char *\fR\fBstrpbrk\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR);
133 .fi
134 .LP
135 .nf
136 \fBconst char *\fR\fBstrrchr\fR(\fBconst char *\fR\fIs\fR, \fBint\fR \fIc\fR);
137 .fi
138 .LP
139 .nf
140 \fBconst char *\fR\fBstrstr\fR(\fBconst char *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR);
141 .fi
142 .LP
143 .nf
144 #include <cstring>
145
146 \fBchar *std::\fR\fBstrchr\fR(\fBchar *\fR\fIs\fR, \fBint\fR \fIc\fR);
147 .fi
148 .LP
149 .nf
150 \fBchar *std::\fR\fBstrpbrk\fR(\fBchar *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR);
151 .fi
152 .LP
153 .nf
154 \fBchar *std::\fR\fBstrrchr\fR(\fBchar *\fR\fIs\fR, \fBint\fR \fIc\fR);
155 .fi
156 .LP
157 .nf
158 \fBchar *std::\fR\fBstrstr\fR(\fBchar *\fR\fIs1\fR, \fBconst char *\fR\fIs2\fR);
159 .fi
160 .SH DESCRIPTION
161 .LP
162 The arguments \fIs\fR, \fIs1\fR, and \fIs2\fR point to strings (arrays of
163 characters terminated by a null character). The \fBstrcat()\fR,
164 \fBstrncat()\fR, \fBstrlcat()\fR, \fBstrcpy()\fR, \fBstrncpy()\fR,
165 \fBstrlcpy()\fR, \fBstrsep()\fR, \fBstrtok()\fR, and \fBstrtok_r()\fR functions
166 all alter their first argument. Additionally, the \fBstrcat()\fR and
167 \fBstrcpy()\fR functions do not check for overflow of the array.
168 .SS "\fBstrcasecmp()\fR, \fBstrncasecmp()\fR"
169 .sp
170 .LP
171 The \fBstrcasecmp()\fR and \fBstrncasecmp()\fR functions are case-insensitive
172 versions of \fBstrcmp()\fR and \fBstrncmp()\fR respectively, described below.
173 .LP
174 The \fBstrcasecmp()\fR and \fBstrncasecmp()\fR functions compare two strings
175 byte-by-byte, after
176 converting each upper-case character to lower-case (as determined by the
177 \fBLC_CTYPE\fR category of the current locale). Note that neither the contents
178 pointed to by \fIs1\fR nor \fIs2\fR are modified.
179 .LP
180 The functions return an integer
181 greater than, equal to, or less than 0, if the string pointed to by \fIs1\fR
182 is greater than, equal to, or less than the string pointed to by \fIs2\fR
183 respectively. The sign of a non-zero return value is determined by the sign of
184 the difference between the values of the first pair of bytes that differ in the
185 .LP
186 The \fBstrncasecmp()\fR function examines at most \fIn\fR bytes from each
187 string.
188 .SS "\fBstrcasecmp_l()\fR, \fBstrncasecmp_l()\fR"
189 .LP
190 The \fBstrcasecmp_l()\fR and \fBstrncasecmp_l()\fR functions behave identically
191 to \fBstrcasecmp()\fR and \fBstrncasecmp()\fR, except instead of operating in
192 the current locale, they instead operate in the locale specified by \fIloc\fR.
193 .SS "\fBstrcat()\fR, \fBstrncat()\fR, \fBstrlcat()\fR"
194 .LP
195 The \fBstrcat()\fR function appends a copy of string \fIs2\fR, including the
196 terminating null character, to the end of string \fIs1\fR. The \fBstrncat()\fR
197 function appends at most \fIn\fR characters. Each returns a pointer to the
198 null-terminated result. The initial character of \fIs2\fR overrides the null
199 character at the end of \fIs1\fR. If copying takes place between objects that
200 overlap, the behavior of \fBstrcat()\fR, \fBstrncat()\fR, and \fBstrlcat()\fR
201 is undefined.
202 .LP
203 The \fBstrlcat()\fR function appends at most
204 (\fIdstsize\fR-\fBstrlen\fR(\fIdst\fR)-1) characters of \fIsrc\fR to \fIdst\fR
205 (\fIdstsize\fR being the size of the string buffer \fIdst\fR). If the string
206 pointed to by \fIdst\fR contains a null-terminated string that fits into
207 \fIdstsize\fR bytes when \fBstrlcat()\fR is called, the string pointed to by
208 \fIdst\fR will be a null-terminated string that fits in \fIdstsize\fR bytes
209 (including the terminating null character) when it completes, and the initial
210 character of \fIsrc\fR will override the null character at the end of
211 \fIdst\fR. If the string pointed to by \fIdst\fR is longer than \fIdstsize\fR
212 bytes when \fBstrlcat()\fR is called, the string pointed to by \fIdst\fR will
213 not be changed. The function returns
214 \fBmin\fR{\fIdstsize\fR,\fBstrlen\fR(\fIdst\fR)}+\fBstrlen\fR(\fIsrc\fR).
215 Buffer overflow can be checked as follows:
216 .sp
217 .in +2
218 .nf
219 if (strlcat(dst, src, dstsize) >= dstsize)
220 return \(mi1;
221 .fi
222 .in -2
223 .SS "\fBstrchr()\fR, \fBstrrchr()\fR"
224 .LP
225 The \fBstrchr()\fR function returns a pointer to the first occurrence of
226 \fIc\fR (converted to a \fBchar\fR) in string \fIs\fR, or a null pointer if
227 \fIc\fR does not occur in the string. The \fBstrrchr()\fR function returns a
228 pointer to the last occurrence of \fIc\fR. The null character terminating a
229 string is considered to be part of the string.
230 .SS "\fBstrcmp()\fR, \fBstrncmp()\fR"
231 .LP
232 The \fBstrcmp()\fR function compares two strings byte-by-byte, according to the
233 ordering of your machine's character set. The function returns an integer
234 greater than, equal to, or less than 0, if the string pointed to by \fIs1\fR
235 is greater than, equal to, or less than the string pointed to by \fIs2\fR
236 respectively. The sign of a non-zero return value is determined by the sign of
237 the difference between the values of the first pair of bytes that differ in the
238 strings being compared. The \fBstrncmp()\fR function makes the same comparison
239 but looks at a maximum of \fIn\fR bytes. Bytes following a null byte are not
240 compared.
241 .SS "\fBstrcpy()\fR, \fBstrncpy()\fR, \fBstrlcpy()\fR"
242 .LP
243 The \fBstrcpy()\fR function copies string \fIs2\fR to \fIs1\fR, including the
244 terminating null character, stopping after the null character has been copied.
245 The \fBstrncpy()\fR function copies exactly \fIn\fR bytes, truncating \fIs2\fR
246 or adding null characters to \fIs1\fR if necessary. The result will not be
247 null-terminated if the length of \fIs2\fR is \fIn\fR or more. Each function
248 returns \fIs1\fR. If copying takes place between objects that overlap, the
249 behavior of \fBstrcpy()\fR, \fBstrncpy()\fR, and \fBstrlcpy()\fR is undefined.
250 .LP
251 The \fBstrlcpy()\fR function copies at most \fIdstsize\fR\(mi1 characters
252 (\fIdstsize\fR being the size of the string buffer \fIdst\fR) from \fIsrc\fR
253 to \fIdst\fR, truncating \fIsrc\fR if necessary. The result is always
254 null-terminated. The function returns \fBstrlen\fR(\fIsrc\fR). Buffer overflow
255 can be checked as follows:
256 .sp
257 .in +2
258 .nf
259 if (strlcpy(dst, src, dstsize) >= dstsize)
260 return \(mi1;
261 .fi
262 .in -2
263
264 .SS "\fBstrcspn()\fR, \fBstrspn()\fR"
265 .LP
266 The \fBstrcspn()\fR function returns the length of the initial segment of
267 string \fIs1\fR that consists entirely of characters not from string \fIs2\fR.
268 The \fBstrspn()\fR function returns the length of the initial segment of string
269 \fIs1\fR that consists entirely of characters from string \fIs2\fR.
270 .SS "\fBstrdup()\fR"
271 .LP
272 The \fBstrdup()\fR function returns a pointer to a new string that is a
273 duplicate of the string pointed to by \fIs1\fR. The returned pointer can be
274 passed to \fBfree()\fR. The space for the new string is obtained using
275 \fBmalloc\fR(3C). If the new string cannot be created, a null pointer is
276 returned and \fBerrno\fR may be set to \fBENOMEM\fR to indicate that the
277 storage space available is insufficient.
278 .SS "\fBstrlen()\fR, \fBstrnlen()\fR"
279 .sp
280 The \fBstrlen()\fR function returns the number of bytes in \fIs\fR, not
281 including the terminating null character.
282 .LP
283 The \fBstrnlen()\fR function returns the smaller of \fIn\fR or the number of
284 bytes in \fIs\fR, not including the terminating null character. The
285 \fBstrnlen()\fR function never examines more than \fIn\fR bytes of the string
286 pointed to by \fIs\fR.
287 .SS "\fBstrpbrk()\fR"
288 .LP
289 The \fBstrpbrk()\fR function returns a pointer to the first occurrence in
290 string \fIs1\fR of any character from string \fIs2\fR, or a null pointer if no
291 character from \fIs2\fR exists in \fIs1\fR.
292 .SS "\fBstrsep()\fR"
293 .LP
294 The \fBstrsep()\fR function locates, in the null-terminated string referenced
295 by *\fIstringp\fR, the first occurrence of any character in the string
296 \fIdelim\fR (or the terminating `\e0' character) and replaces it with a `\e0'.
297 The location of the next character after the delimiter character (or
298 \fINULL\fR, if the end of the string was reached) is stored in *\fIstringp\fR.
299 The original value of *\fIstringp\fR is returned.
300 .LP
301 An ``empty'' field (one caused by two adjacent delimiter characters) can be
302 detected by comparing the location referenced by the pointer returned by
303 \fBstrsep()\fR to `\e0'.
304 .LP
305 If *\fIstringp\fR is initially \fINULL\fR, \fBstrsep()\fR returns \fINULL\fR.
306 .SS "\fBstrstr()\fR"
307 .LP
308 The \fBstrstr()\fR function locates the first occurrence of the string \fIs2\fR
309 (excluding the terminating null character) in string \fIs1\fR and returns a
310 pointer to the located string, or a null pointer if the string is not found. If
311 \fIs2\fR points to a string with zero length (that is, the string \fB""\fR),
312 the function returns \fIs1\fR.
313 .SS "\fBstrtok()\fR"
314 .LP
315 A sequence of calls to \fBstrtok()\fR breaks the string pointed to by \fIs1\fR
316 into a sequence of tokens, each of which is delimited by a byte from the string
317 pointed to by \fIs2\fR. The first call in the sequence has \fIs1\fR as its
318 first argument, and is followed by calls with a null pointer as their first
319 argument. The separator string pointed to by \fIs2\fR can be different from
320 call to call.
321 .LP
322 The first call in the sequence searches the string pointed to by \fIs1\fR for
323 the first byte that is not contained in the current separator string pointed to
324 by \fIs2\fR. If no such byte is found, then there are no tokens in the string
325 pointed to by \fIs1\fR and \fBstrtok()\fR returns a null pointer. If such a
326 byte is found, it is the start of the first token.
327 .LP
328 The \fBstrtok()\fR function then searches from there for a byte that is
329 contained in the current separator string. If no such byte is found, the
330 current token extends to the end of the string pointed to by \fIs1\fR, and
331 subsequent searches for a token return a null pointer. If such a byte is found,
332 it is overwritten by a null byte that terminates the current token. The
333 \fBstrtok()\fR function saves a pointer to the following byte in
334 thread-specific data, from which the next search for a token starts.
335 .LP
336 Each subsequent call, with a null pointer as the value of the first argument,
337 starts searching from the saved pointer and behaves as described above.
338 .LP
339 See Example 1, 2, and 3 in the \fBEXAMPLES\fR section for examples of
340 \fBstrtok()\fR usage and the explanation in \fBNOTES\fR.
341 .SS "\fBstrtok_r()\fR"
342 .LP
343 The \fBstrtok_r()\fR function considers the null-terminated string \fIs1\fR as
344 a sequence of zero or more text tokens separated by spans of one or more
345 characters from the separator string \fIs2\fR. The argument \fIlasts\fR points
346 to a user-provided pointer which points to stored information necessary for
347 \fBstrtok_r()\fR to continue scanning the same string.
348 .LP
349 In the first call to \fBstrtok_r()\fR, \fIs1\fR points to a null-terminated
350 string, \fIs2\fR to a null-terminated string of separator characters, and the
351 value pointed to by \fIlasts\fR is ignored. The \fBstrtok_r()\fR function
352 returns a pointer to the first character of the first token, writes a null
353 character into \fIs1\fR immediately following the returned token, and updates
354 the pointer to which \fIlasts\fR points.
355 .LP
356 In subsequent calls, \fIs1\fR is a null pointer and \fIlasts\fR is unchanged
357 from the previous call so that subsequent calls move through the string
358 \fIs1\fR, returning successive tokens until no tokens remain. The separator
359 string \fIs2\fR can be different from call to call. When no token remains in
360 \fIs1\fR, a null pointer is returned.
361 .LP
362 See Example 3 in the \fBEXAMPLES\fR section for an example of \fBstrtok_r()\fR
363 usage and the explanation in \fBNOTES\fR.
364 .SH EXAMPLES
365 .LP
366 \fBExample 1 \fRSearch for word separators.
367 .LP
368 The following example searches for tokens separated by space characters.
369
370 .sp
371 .in +2
372 .nf
373 #include <string.h>
374 \&...
375 char *token;
376 char line[] = "LINE TO BE SEPARATED";
377 char *search = " ";
378
379 /* Token will point to "LINE". */
380 token = strtok(line, search);
381
382 /* Token will point to "TO". */
383 token = strtok(NULL, search);
384 .fi
385 .in -2
386
387 .LP
388 \fBExample 2 \fRBreak a Line.
389 .LP
390 The following example uses strtok to break a line into two character strings
391 separated by any combination of SPACEs, TABs, or NEWLINEs.
392
393 .sp
394 .in +2
395 .nf
396 #include <string.h>
397 \&...
398 struct element {
399 char *key;
400 char *data;
401 };
402 \&...
403 char line[LINE_MAX];
404 char *key, *data;
405 \&...
406 key = strtok(line, " \en");
407 data = strtok(NULL, " \en");
408 .fi
409 .in -2
410
411 .LP
412 \fBExample 3 \fRSearch for tokens.
413 .LP
414 The following example uses both \fBstrtok()\fR and \fBstrtok_r()\fR to search
415 for tokens separated by one or more characters from the string pointed to by
416 the second argument, "/".
417
418 .sp
419 .in +2
420 .nf
421 #define __EXTENSIONS__
422 #include <stdio.h>
423 #include <string.h>
424
425 int
426 main() {
427 char *buf="5/90/45";
428 char *token;
429 char *lasts;
430
431 printf("tokenizing \e"%s\e" with strtok():\en", buf);
432 if ((token = strtok(buf, "/")) != NULL) {
433 printf("token = "%s\e"\en", token);
434 while ((token = strtok(NULL, "/")) != NULL) {
435 printf("token = \e"%s\e"\en", token);
436 }
437 }
438
439 buf = "//5//90//45//";
440 printf("\entokenizing \e"%s\e" with strtok_r():\en", buf);
441 if ((token = strtok_r(buf, "/", &lasts)) != NULL) {
442 printf("token = \e"%s\e"\en", token);
443 while ((token = strtok_r(NULL, "/", &lasts)) != NULL) {
444 printf("token = \e"%s\e"\en", token);
445 }
446 }
447 }
448 .fi
449 .in -2
450
451 .LP
452 When compiled and run, this example produces the following output:
453
454 .sp
455 .in +2
456 .nf
457 tokenizing "5/90/45" with \fBstrtok()\fR:
458 token = "5"
459 token = "90"
460 token = "45"
461
462 tokenizing "//5//90//45//" with \fBstrtok_r()\fR:
463 token = "5"
464 token = "90"
465 token = "45"
466 .fi
467 .in -2
468
469 .SH ATTRIBUTES
470 .LP
471 See \fBattributes\fR(5) for descriptions of the following attributes:
472 .TS
473 box;
474 c | c
475 l | l .
476 ATTRIBUTE TYPE ATTRIBUTE VALUE
477 _
478 Interface Stability See below.
479 _
480 MT-Level See below.
481 _
482 Standard See below.
483 .TE
484
485 .LP
486 The
487 \fBstrlcat()\fR, \fBstrlcpy()\fR, and \fBstrsep()\fR functions are Committed.
488 All the rest are Standard.
489 .LP
490 The \fBstrtok()\fR and \fBstrdup()\fR functions are MT-Safe. The remaining
491 functions are Async-Signal-Safe.
492 .LP
493 For all except \fBstrlcat()\fR, \fBstrlcpy()\fR, and \fBstrsep()\fR, see
494 \fBstandards\fR(5).
495 .SH SEE ALSO
496 .LP
497 \fBmalloc\fR(3C),
498 \fBnewlocale(3C), \fBsetlocale\fR(3C), \fBstrxfrm\fR(3C), \fBuselocale\fR(3C),
499 \fBattributes\fR(5), \fBstandards\fR(5)
500 .SH NOTES
501 .LP
502 When compiling multithreaded applications, the \fB_REENTRANT\fR flag must be
503 defined on the compile line. This flag should only be used in multithreaded
504 applications.
505 .LP
506 A single-threaded application can gain access to \fBstrtok_r()\fR only by
507 defining \fB__EXTENSIONS__\fR or by defining \fB_POSIX_C_SOURCE\fR to a value
508 greater than or equal to 199506L.
509 .LP
510 Except where noted otherwise, all of these functions assume the default
511 locale ``C.'' For some locales,
512 \fBstrxfrm\fR(3C) should be applied to the strings before they are passed to
513 the functions.
514 .LP
515 The \fBstrtok()\fR function is safe to use in multithreaded applications
516 because it saves its internal state in a thread-specific data area. However,
517 its use is discouraged, even for single-threaded applications. The
518 \fBstrtok_r()\fR function should be used instead.
519 .LP
520 Do not pass the address of a character string literal as the argument \fIs1\fR
521 to either \fBstrtok()\fR or \fBstrtok_r()\fR. Similarly, do not pass a pointer
522 to the address of a character string literal as the argument \fIstringp\fR to
523 \fBstrsep()\fR. These functions can modify the storage pointed to by \fIs1\fR
524 in the case of \fBstrtok()\fR and \fBstrtok_r()\fR or *\fIstringp\fR in the
525 case of \fBstrsep()\fR. The C99 standard specifies that attempting to modify
526 the storage occupied by a string literal results in undefined behavior. This
527 allows compilers (including \fBgcc\fR and the Sun Studio compilers when the
528 \fB-xstrconst\fR flag is used) to place string literals in read-only memory.
529 Note that in Example 1 above, this problem is avoided because the variable
530 \fIline\fR is declared as a writable array of type \fBchar\fR that is
531 initialized by a string literal rather than a pointer to \fBchar\fR that points
532 to a string literal.