STRSEP(3)

STRSEP(3) | Library Functions Manual | STRSEP(3)

# NAME

`strsep`, `stresep` —
separate strings

# LIBRARY

Standard C Library (libc, -lc)

# SYNOPSIS

`#include <string.h>`

char *
`strsep`(char **stringp, const char *delim);

char *
`stresep`(char **stringp, const char *delim, int escape);

# DESCRIPTION

The `strsep`() function locates, in the nul-terminated 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 returned by `strsep`() to ‘`\0`’.

If *stringp is initially `NULL`, `strsep`() returns `NULL`. The `stresep`() function also takes an escape character that allows quoting the delimiter character so that it can be part of the source string.

# EXAMPLES

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 < &argv[9] &&
        (*ap = strsep(&inputstring, " \t")) != NULL;) {
    	if (**ap != '\0')
    		ap++;
    }

# HISTORY

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 ANSI X3.159-1989 (“ANSI C89”)) 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.

August 12, 2006 | NetBSD 9.0