wcat.c

// OS Assignment-1 Copyright@Amit_Kumar Singh Yadav - 16110011 
// Question-1 Replicating cat function of UNIX Shell
 
#include <stdio.h> // for standard input and output- fgets, fclose, fopen
#include <stdlib.h> // for exit
#define BUFFER_SIZE 1000 //Buffer size=1000 characters
 
int main (int argc, char *argv[]) // argc: number of arguments including first argument as file name itself

{
for (int i=1; i<argc;i++) // Loop to sequentially process each filepath passed and display it's content
	{
	FILE *filep = fopen(argv[i], "r");// open each file in Read mode with cursor at the beginning
	if (filep == NULL) // if file path doesn't exit- exit
		{
		    printf("wcat: cannot open file\n");
		    exit(1); // Exit with status code = 1 
		}

	else // else read line by line and print it 
		{


		char buffer[BUFFER_SIZE]; //
		fgets(buffer,BUFFER_SIZE,filep);
// first is char * type, second is size, third should be FILE type pointer; 1 fgets outside loop ensure wcat not print previous buffer (last line) twice if passed with multiple files. 
			
		while (!feof(filep)) // print till eof is reached - "\0"
			{
			
			printf("%s", buffer);
			fgets(buffer,BUFFER_SIZE,filep);
			}
		fclose(filep); // close that file
		

		}
	}
exit(0); // exit if all files content displayed correctly or no file name passed with status code =0
}