C string library function memchr( )

In this tutorial, you will learn in-depth about C string library function memchr( ) with explanation and explicit example.

memchr( ) is the built in standard library function that is defined in the string library string.h. Therefore, we should include string header library before using it.

#include<string.h>

Function prototype of C string library function memchr( )

void *memchr( const void *str, int ch, size_t n );

where,

               str = Pointer to the object or block of the memory that needs to be scanned

              ch = value that needs to be passed that is represented as unsigned char

               n = Size of content in bytes to be scanned

This function searches for the first occurrence of a character ch in the n bytes of characters in the block of memory pointed by str.

It returns a pointer to the matching byte if the searched byte was found, otherwise, a NULL pointer is returned.

Let’s get a clear idea from the following example:

C program to demonstrate the use of string library function memchr( )

/*Use of string library function memchr*/

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

int main()
{
   //initializing character pointer
   const char *str = "Learn C from trytoprogram.com";
   const char ch = 't';

   //displaying str
   printf("str = %s\n\n", str);

   printf("Remaining string after '%c' : %s\n", ch, (char *) memchr( str, ch, strlen(str)));

   return 0;
}//end

Output

Explanation

In the above program, we have searched for 't' in the block of memory pointed by str.

strlen( ) is used to determine the length of str.

It locates the first occurrence of ch and displays the remaining string as shown in the output.