STRSEP(3) BSD Programmer's Manual STRSEP(3)
strsep - separate strings
#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., one caused by two adjacent delimiter characters, can be detected by comparing the location referenced by the pointer re- turned by strsep() to '\0'. If *stringp is initially NULL, strsep() returns NULL.
The following uses strsep() to parse a string, containing tokens delimit- ed by whitespace, into an argument vector: char **ap, *argv[10], *inputstring; for (ap = argv; ap < &argv[9] && (*ap = strsep(&inputstring, " \t")) != NULL;) { if (**ap != '\0') ap++; } *ap = NULL;
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 ANSI X3.159-1989 ("ANSI C89")) 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. MirBSD #10-current June 9, 1993 1