Design, Develop and Implement a program in C for the following operations on Stringsa. The strcmp() function is used to compare two strings two strings str1 and str2 . How to print repeating substring/patterns in a given string using C - Quora Sub String can be found using while loop. strstr implementation in c without using library function strstr implementation in c without using library function your head. . String in C - Tutorial And Example Above is the source code for C Program to Compare Two Strings without using strcmp function which is successfully compiled . This program will implement substring function without using any string library function, this program will copy given number of characters from given number of bytes in one string to another string and that target string is called substring of source string.. s2 strstr, wcsstr, _mbsstr, _mbsstr_l | Microsoft Docs Implement strcpy() function in C - Techie Delight How to control and use string functions like strlen(), strcpy(), strcat(), strcmp() and know more about gets() or puts() as well as here you get string function examples with output results. Here you will get C++ program to find length of a string without using library function. Input : str [] = 'My name is Ayush', ch1 = 'A', ch2 = 'z'. You can probably hide the violation somehow (for example you could use memcpy () to copy the pointer value), but there's no point in doing so. We create a function and pass it four arguments original string array, substring array, position, and length of the required substring. string.h is the header file required for string functions.. In my opinion if you know a clever versions exists is enough (because in real life I would Google "efficient strstr implementation") if you happen to know the name even . The only library function you call is printf(), . then bet that you can write strstr without using any local variables or calling any other external routines.