June 4, 1993 INDEX 3

### NAME

index - locate character in string

### LIBRARY

Standard C Library (libc, -lc)

### SYNOPSIS

```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)

### HISTORY

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