NAME

index, rindex, strchr, strrchr − Search for character in string

LIBRARY

Standard C Library (libc.so, libc.a)

SYNOPSIS

#include <strings.h>

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

char ∗rindex(
        const char ∗s,
        int c);

#include <string.h>

char ∗strchr(
        const char ∗s,
        int c);

char ∗strrchr(
        const char ∗s,
        int c);

STANDARDS

Interfaces documented on this reference page conform to industry standards as follows:

index(), rindex():  XPG4−UNIX

strchr(), strrchr():  XPG4, XPG4−UNIX

Refer to the standards(5) reference page for more information about industry standards and associated tags. 

PARAMETERS

sSpecifies the string to search. 

cSpecifies a character, expressed as an int data type, to search for. 

DESCRIPTION

The index() function locates the first occurrence of the integer specified by the c parameter, which is converted to an unsigned char, in the string pointed to by the s parameter.  The terminating null byte is treated as part of the string pointed to by the s parameter. 

The rindex() function locates the last occurrence of the integer specified by the c parameter, which is converted to a char value, in the string pointed to by the s parameter.  The terminating null byte is treated as a part of the string pointed to by the s parameter. 

The strchr() and strrchr() functions provide the same functionality as the index() and rindex() functions, respectively. 

If c is a null byte (’\0’) in any of these functions, the function locates the terminating null byte of s. 

RETURN VALUES

Upon successful completion, these functions return a pointer to the byte in the scanned string. When the byte specified by parameter c is not found, a null pointer is returned. 

RELATED INFORMATION

Functions: string(3), wcschr(3)

Standards: standards(5)