wc.c

This is to bulid a sample linux shell.

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

int l=0,w=0,c=0,i;

int main(int argc, char *argv[])
{
	if(argc<2||argc>3)
	{
		printf("daemon: Insufficient or Extra Arguments.\n");
		return(0);
	}	
	FILE *fp;
	if(argv[1][0]=='-')	
		fp=fopen(argv[2],"r");
	else
		fp=fopen(argv[1],"r");
	if(fp==NULL)
	{
		if(argc==2)
			printf("daemon: %s file not found.\n",argv[1]);
		else
			printf("daemon: %s file not found.\n",argv[2]);
		return(0);
	}
	char ch;
	ch=getc(fp);
	while(ch!=EOF)
	{
		switch(ch)
		{
			case ' ' : w++; c++;i=1;break;
			case '\n': l++; w++;c++;i=0;break;
			default  : c++;i=1;break;
		}
		ch=getc(fp);
	}
	if(i)
		w++;
	if(argc==3)
	{
	if(strcmp(argv[1],"-l")==0)
		printf("\t%d\t%s\n",l,argv[2]);
	else if(strcmp(argv[1],"-w")==0)
		printf("\t%d\t%s\n",w,argv[2]);
	else if(strcmp(argv[1],"-c")==0)
		printf("\t%d\t%s\n",c,argv[2]);
	else
		printf("daemon: Invalid Option.\n");
	}
	if(argc==2)
		printf("\t%d\t%d\t%d\t%s\n",l,w,c,argv[1]);
	fclose(fp);
	return 1;
}