CODEWITHSUNDEEP
c
Tincan
Tincan

Reputation: 1

No content using fputc

I am attempting to complete a lab. When I run this code nothing is written to the text file that is created. According to the lab it should write A thru Z to the text file.

//Example program #1. Chapter 29
// File Chapter29exl.c

/* The program open a file named letters.txt and prints A through Z in the file.
It then loops backward through the file printing each of the letters from z to A. */

#include <stdio.h>
#include <stdlib.h>
FILE * fptr;

main()
{
char letter;
int i;

fptr = fopen("letters.txt", "w+");

if (fptr == 0)
{
    printf(" There was an error while opening the file.\n");
    exit(1);
}

for (letter = 'A'; letter <= 'Z'; letter++)
{
    fputc(letter, fptr);
}

puts("Just wrote the letters A through Z");

//Now read the file backwards

fseek(fptr, -1, SEEK_END);  // Minus 1 byte from the end
printf("Here is the file backwards:\n");
for (i = 26; i > 0; i--)
{
    letter = fgetc(fptr);
    //Reads a letter, then backs up 2
    fseek(fptr, -2, SEEK_CUR);
    printf("The next letter is %c/\n, leeter");
}

fclose(fptr);
return(0);
}

The code created the file but it is blank. Thanks

Upvotes: 0

Views: 53

Answers (1)

Aziz
Aziz

Reputation: 20745

In line, you're not passing the variable for %c, only a string

printf("The next letter is %c/\n, leeter");

It should be:

printf("The next letter is %c/\n", letter);

You can detect this easily if you look at the compiler warnings. By default, GCC produces the following warning for your code:

 warning: format '%c' expects a matching 'int' argument [-Wformat=]
       printf("The next letter is %c/\n, leeter");

Indicating the argument is missing.

Upvotes: 1

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