strstr function(Search String for Substring) in C Language – example and detail

In the C Programming Language, the strstr function searches inside the string pointed to by way of s1 for the string pointed to with the aid of s2. It returns a pointer to the first occurrence in s1 of s2.


The syntax for the strstr function in the C Language is:

char *strstr(const char *s1, const char *s2);

Parameters or Arguments

s1 A string to search within. s2 The substring that you prefer to find.


The strstr function returns a pointer to the first incidence s2 within the string pointed to via s1. If s2 isn’t always found, it returns a null pointer.

Required Header

In the C Language, the required header for the strstr characteristic is:

#include <string.h>

Applies To

In the C Language, the strstr feature can be used in the following versions:

ANSI/ISO 9899-1990

See Also

Other C features that are noteworthy when dealing with the strstr function:

memchr characteristic strchr function strpbrk characteristic strrchr function