INDEX(3) BSD Library Functions Manual INDEX(3)NAME
index, rindex — locate character in string
Standard C Library (libc, -lc)
index(const char *s, int c);
rindex(const char *s, int c);
The index() function locates the first occurrence of c (converted to a
char) in the string pointed to by s. The terminating null character is
considered part of the string; therefore if c is ‘\0’, the functions
locate the terminating ‘\0’.
The rindex() function is identical to index(), except it locates the last
occurrence of c.
The functions index() and rindex() return a pointer to the located char‐
acter, or NULL if the character does not appear in the string.
SEE ALSOmemchr(3), strchr(3), strcspn(3), strpbrk(3), strrchr(3), strsep(3),
strspn(3), strstr(3), strtok(3)HISTORY
The index() and rindex() functions appeared in Version 6 AT&T UNIX.
Their prototypes existed previously in <string.h> before they were moved
to <strings.h> for IEEE Std 1003.1-2001 (“POSIX.1”) compliance.
BSD June 4, 1993 BSD