strstr()

Find one string inside another

Synopsis:

#include <string.h>

char* strstr(char* str,
             char* substr );

Arguments:

str: The string that you want to search.
substr: The string that you're looking for.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The strstr() function locates the first occurrence in the string pointed to by str of the sequence of characters (excluding the terminating null character) in the string pointed to by substr. If substr is an empty string, the function returns str.

The non-POSIX strcasestr() function is similar, but it ignores the case of both arguments.

Returns:

A pointer to the located string, or NULL if the string isn't found.

Examples:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main( void )
  {
    printf( "%s\n", strstr("This is an example", "is") );
    return EXIT_SUCCESS;
  }

produces the output:

is is an example

Classification:

ANSI, POSIX 1003.1

Safety:
Cancellation point	No
Interrupt handler	Yes
Signal handler	Yes
Thread	Yes