DragonFly On-Line Manual Pages

Search: Section:  

STRSEP(3)	      DragonFly 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 delim- ited 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() func- tion. 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 delim- iter characters, or to be used for more than a single string at a time. The strsep() function first appeared in 4.4BSD. DragonFly 4.7 December 5, 2008 DragonFly 4.7

Search: Section: