strsep(3) -- Linux man page
NAMEstrsep - extract token from string
#include <string.h> char *strsep(char **stringp, const char *delim);
DESCRIPTIONIf *stringp is NULL, the strsep() function returns NULL and does nothing else. Otherwise, this function finds the first token in the string *stringp, where tokens are delimited by symbols in the string delim. This token is terminated with a `\0' character (by overwriting the delimiter) and *stringp is updated to point past the token. In case no delimiter was found, the token is taken to be the entire string *stringp, and *stringp is made NULL.
RETURN VALUEThe strsep() function returns a pointer to the token, that is, it returns the original value of *stringp.
NOTESThe strsep() function was introduced as a replacement for strtok(), since the latter cannot handle empty fields. However, strtok() conforms to ANSI-C and hence is more portable.
BUGSThis function suffers from the same problems as strtok(). In particular, it modifies the original string. Avoid it.
CONFORMING TOBSD 4.4
SEE ALSOindex(3), memchr(3), rindex(3), strchr(3), strpbrk(3), strspn(3), strstr(3), strtok(3)