CS456 - Systems Programming Spring 2026

Displaying ./code/jan28/wc_simple.c

/*

a simple implentation of the wc command

this takes a file and prints the count of lines, words and characters in a file

*/
#include <stdio.h>
#include <stdlib.h>
#include <errno.h> //needed for perror
int main(int argc, char **argv){

	//check if file was provided , otherwise print usage statement and exit
	if(argc < 2){
		fprintf(stderr, "Usage: %s file\n", argv[0]);
		exit(1);
	}	

	//read in a file from the command line using fopen
	FILE *fp = fopen(argv[1], "r");

	// checking return value of fopen
	// if fopen returns NULL, then it failed, so print error message and exit
	if (fp == NULL){
		perror("fopen");
		exit(-1);
	}	

	int c; //fgetc returns an int, hence declaring c as an int
	
	//variable declarations for things we're keeping a count of
	int lines = 0;
	int words = 0;
	int chars = 0;
	

	
	//loop through entire file
	while((c =fgetc(fp))!= EOF){
		if(c == '\n'){ //see a new line. so increment the count of lines and words
	           lines++;
	           words++;
		}
		if(c == ' ') words++; //see a space character, so we probably have a word, so increment the count
		
		chars++; //increment the count of characters

	}	

	
	fclose(fp); //closing the file as we're done with it

	//printing the results
	printf("%s has %d lines, %d words, and %d characters\n", argv[1], lines, words, chars);

	return 0;

}