strstr [C++ Reference]
Keywords: c,string,strstr
Date: 2010-03-08T05:15:23-0800

## strstr

Syntax:

        #include <cstring>
        const char *strstr( const char *str1, const char *str2 );
              char *strstr(       char *str1, const char *str2 );

The function `strstr` returns a pointer to the first occurrence of `str2` in `str1`, or `NULL` if no match is found. If the length of `str2` is zero, then `strstr` will simply return `str1`.

For example, the following code checks for the existence of one string within another string:

        char* str1 = "this is a string of characters";
        char* str2 = "a string";
        char* result = strstr( str1, str2 );
        if( result == NULL ) printf( "Could not find '%s' in '%s'\n", str2, str1 );
        else printf( "Found a substring: '%s'\n", result );

When run, the above code displays this output:

        Found a substring: 'a string of characters'

Related Topics: memchr, strchr, strcspn, strpbrk, strrchr, strspn, strtok