C Strings:
Write a C program to replace the sub string in a string with another string.
In this program, We replace string with another string, if the entered string is the sub string of main string, otherwise function replace_str returns the original string as it is. Read more about C Programming Language .

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

char *replace_str(char *str, char *orig, char *rep)
{
    static char buffer[4096];
    char *p;

    if(!(p = strstr(str, orig)))
    return str;

    strncpy(buffer, str, p-str);
    buffer[p-str] = '