c-string append (concat)

append.c

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

const char* append( const char* str1, const char* str2 ) {
	const size_t str1_length = strlen( str1 );
	const size_t str2_length = strlen( str2 );
	const size_t total_length = str1_length + str2_length;

	char *const str_buff =(char*) malloc( total_length + 1 );
	if ( str_buff == NULL ) {
		fprintf( stderr, "malloc failed\n" );
		exit( EXIT_FAILURE );
	}

	strcpy( str_buff, str1 );
	strcpy( str_buff + str1_length, str2 );

	return str_buff;
}


int main( void ) {

	puts( append( "Milad", " Khajavi" ) );

	return 0;
}