C program using command line arguments to search for a word in a file and replace it with the specified word.

Write a ‘C’ program using command line arguments to search for a word in a file and replace it with the specified word.

#include<stdio.h>
#include<conio.h>
void main(int argc,char *argv[])
{
FILE *fp,*fq;
char ch;
clrscr();
if(argc!=4)
{
printf("improper no of argument");
exit(0);
}
fp=fopen(argv[1],"r");
if(fp==NULL)
{
printf("file does not exist");
exit(0);
}
fq=fopen("b.txt","w");
if(fq==NULL)
{
printf("file does not exist");
exit(0);
}
while(1)
{
ch=fgetc(fp);
if(ch==EOF)
 break;
if(ch==*argv[2])
{
  fputc(*argv[3],fq);
}
else
{
 fputc(ch,fq);
}
}
 fclose(fp);
 fclose(fq);
 fp=fopen("b.txt","r");
 fq=fopen(argv[1],"w");
 while(1)
 {
   ch=fgetc(fp);
   if(ch==EOF)
      break;
   fputc(ch,fq);
 }
 getch();
       }