STRSEP(3) | Library Functions Manual | STRSEP(3) |
strsep
— separate
strings
Standard C Library (libc, -lc)
#include
<string.h>
char *
strsep
(char
**stringp, const char
*delim);
The
strsep
()
function locates, in the string referenced by
*stringp, the first occurrence of any character in the
string delim (or the terminating
‘\0
’ character) and replaces it with a
‘\0
’. The location of the next
character after the delimiter character (or NULL, if the end of the string
was reached) is stored in *stringp. The original value
of *stringp is returned.
An “empty” field (i.e., a character in the string
delim occurs as the first character of
*stringp) can be detected by comparing the location
referenced by the returned pointer to
‘\0
’.
If *stringp is initially
NULL
,
strsep
()
returns NULL
.
The following uses strsep
() to parse a
string, and prints each token in separate line:
char *token, *string, *tofree; tofree = string = strdup("abc,def,ghi"); assert(string != NULL); while ((token = strsep(&string, ",")) != NULL) printf("%s\n", token); free(tofree);
The following uses strsep
() to parse a
string, containing tokens delimited by white space, into an argument
vector:
char **ap, *argv[10], *inputstring; for (ap = argv; (*ap = strsep(&inputstring, " \t")) != NULL;) if (**ap != '\0') if (++ap >= &argv[10]) break;
memchr(3), strchr(3), strcspn(3), strpbrk(3), strrchr(3), strspn(3), strstr(3), strtok(3)
The strsep
() function is intended as a
replacement for the strtok
() function. While the
strtok
() function should be preferred for
portability reasons (it conforms to ISO/IEC 9899:1990
(“ISO C90”)) it is unable to handle empty
fields, i.e., detect fields delimited by two adjacent delimiter characters,
or to be used for more than a single string at a time. The
strsep
() function first appeared in
4.4BSD.
December 5, 2008 | macOS 14.6 |