#include <stdio.h>
#include <string.h>
#define MAX 256
int main()
{
FILE *fptr1, *fptr2;
int lno, linectr = 0;
char str[MAX],fname[MAX] = "text.txt";
char newln[MAX], temp[] = "temp.txt";
printf("\n\nC Program to Replace a Specific Line in a Text File.\n\n");
printf("-------------------------------------------------------------\n");
printf("-------------------------------------------------------------\n\n");
fptr1 = fopen(fname, "r");
if (!fptr1)
{
printf("Unable to open the input file!!\n");
return 0;
}
fptr2 = fopen(temp, "w");
if (!fptr2)
{
printf("Unable to open a temporary file to write!!\n");
fclose(fptr1);
return 0;
}
printf("\t-Input the content of the new line: ");
fgets(newln, MAX, stdin);
printf("\n\t-Input the number of line you want to replace: ");
scanf("%d", &lno);
while (!feof(fptr1))
{
strcpy(str, "\0");
fgets(str, MAX, fptr1);
if (!feof(fptr1))
{
linectr++;
if (linectr != lno)
{
fprintf(fptr2, "%s", str);
}
else
{
fprintf(fptr2, "%s", newln);
}
}
}
fclose(fptr1);
fclose(fptr2);
remove(fname);
rename(temp, fname);
printf("\n\nReplacement did successfully..!! \n");
return 0;
}