NAME
strsep, stresep
— separate strings
LIBRARY
library “libc”
SYNOPSIS
#include
<string.h>
char *
strsep(char
**stringp, const char
*delim);
char *
stresep(char
**stringp, const char
*delim, int
escape);
DESCRIPTION
Thestrsep()
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.