NAME

index — locate character in string

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <strings.h>

char *
index(const char *s, int c);

DESCRIPTION

The index() function locates the first character matching c (converted to a char) in the nul-terminated string s.

RETURN VALUES

A pointer to the character is returned if it is found; otherwise NULL is returned. If c is '\0', index() locates the terminating '\0'.

SEE ALSO

memchr(3), rindex(3), strchr(3), strcspn(3), strpbrk(3), strrchr(3), strsep(3), strspn(3), strstr(3), strtok(3)

STANDARDS

The index() function conforms to IEEE Std 1003.1-2001 (“POSIX.1”). The IEEE Std 1003.1-2004 (“POSIX.1”) revision marked it as legacy and recommended the use of strchr(3) instead. The IEEE Std 1003.1-2008 (“POSIX.1”) revision removed index() from the specification.

HISTORY

An index() function appeared in Version 6 AT&T UNIX.