Replace A Word In A File

Replace a word in a file

Find a specific word from an existing file and replace that word with another.

Code

/******Word replace in a file******/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main()
{
 FILE *fp,*fp1;
 char str[15],str1[15],fname[20],ch;
 int i=0,len,flag,x=0;
 //Creating a file
 printf("\nEnter a file name:");
 gets(fname);
 fp=fopen(fname,"w");
 if(fp==NULL){
  printf("\nFile cannot be created.");
  exit(0);
 }
 if(ferror(fp)!=0){
  printf("\nFile become damage or corrupt.");
  exit(0);
 }
 //Enter the content in the file
 printf("\nEnter the content of the file. press ctrl+z after compulsion.\n\n");
 while((ch=getchar())!=EOF)
  putc(ch,fp);
 fclose(fp);
 //Open the file in read mode
 fp=fopen(fname,"r");
 if(fp==NULL){
  printf("\nFile cannot be created.");
  exit(0);
 }
 if(ferror(fp)!=0){
  printf("\nFile become damage or corrupt.");
  exit(0);
 }
 //Print the content of the file
 printf("\nThe content of the current file is:\n");
 while((ch=getc(fp))!=EOF)
  printf("%c",ch);
 fclose(fp);
 //Open the file in read mode
 fp=fopen(fname,"r");
 if(fp==NULL){
  printf("\nFile cannot be created.");
  exit(0);
 }
 if(ferror(fp)!=0){
  printf("\nFile become damage or corrupt.");
  exit(0);
 }
 //Taking input of the word to be replace
 printf("\nEnter the word you want to replace: ");
 scanf("%s",str);
 len=strlen(str);
 printf("\nEnter replaced word: ");
 scanf("%s",str1);
 //Open a new file to copy all the content of the old file with the replace word
 fp1=fopen("new.txt","w");
 if(fp==NULL){
  printf("\nFile cannot be created.");
  exit(0);
 }
 if(ferror(fp)!=0){
  printf("\nFile become damage or corrupt.");
  exit(0);
 }
 while((ch=getc(fp))!=EOF){
  if((ch!=32) && (ch!='\n')){
   flag=0; 
   i=0;
   do{
    if((ch==str[i]) && (i<len))
     i++;
    else{
     flag=1;
     break;
    }   
   }while(((ch=getc(fp))!=EOF) && (ch!=32) && (ch!='.') && (ch!='\n') && (ch!='?') && (ch!='!'));
  
   if(flag==0){
    fprintf(fp1,"%s",str1);
    if(ch==32) putc(ch,fp1);
    if(ch=='\n') putc(ch,fp1);
    if(ch=='?') fprintf(fp1,"%c ",ch);
    if(ch=='!') fprintf(fp1,"%c ",ch);
    if(ch=='.') fprintf(fp1,"%c ",ch);
    x++;
   }
   else{
    if(i!=0)
     fseek(fp,-(i+1),SEEK_CUR);
    do{
     putc(ch,fp1);
    }while(((ch=getc(fp))!=EOF) && (ch!=32) && (ch!='.') && (ch!='\n') && (ch!='?') && (ch!='!'));
    if(ch==32) putc(ch,fp1);
    if(ch=='\n') putc(ch,fp1);
    if(ch=='?') fprintf(fp1,"%c ",ch);
    if(ch=='!') fprintf(fp1,"%c ",ch);
    if(ch=='.') fprintf(fp1,"%c ",ch);
   }
  }
 }
 printf("\n%d word(s) are found and replace successfully.",x);
 fclose(fp);
 fclose(fp1);

 fp1=fopen("new.txt","r");
 printf("\nThe content of the new file is:\n");
 while((ch=getc(fp1))!=EOF)
  printf("%c",ch);
 
 fclose(fp1);
 return 0;
}

Output

Enter a file name:temp.txt
Enter the content of the file. press ctrl+z after compulsion.
This is a temp file. This file is for testing.
^Z
The content of the current file is:
This is a temp file. This file is for testing.
Enter the word you want to replace: file
Enter replaced word: program
2 word(s) are found and replace successfully.
The content of the new file is:
This is a temp program. This program is for testing.