write a file to stdout

[narniat]

Just for exercising some new things I've learned, I wrote this [useless] code which does actually the same thing "ls >> ..." does:

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

int main()
{

  system("ls > list_of_files.txt");
  FILE *f = fopen("list_of_files.txt", "r");
  char *content;
  fseek(f, 0L, SEEK_END);
  long size = ftell(f);
  rewind(f);
  content = malloc(sizeof(char) * size);
  fread(content, sizeof(char), size, f);
  puts(content);
  printf("%lu\n", size);

  return 0;
}

however, then I thought that might also be possible to remove some lines by just straightly reading from the file and writing to the stdout. the code inside main:

system("ls -la > list_of_files.txt");
FILE *f = fopen("list_of_files.txt", "r");
fseek(f, 0L, SEEK_END);
long size = ftell(f);
rewind(f);
fread(stdout, sizeof(char), size, f);

which gives an error: segmentation fault(core dump). So I searched this error and it's when OS detects a program is trying to access a memory address that does not belong to it, so where have I done such a thing? Thanks in advance.

[Salem]

Because you don't write to stdout just by using it as a random pointer in some other API.

fread(stdout, sizeof(char), size, f);
no more writes to stdout than
strcat(stdout,"hello world")
would.

The first one is better, but you can improve by using popen() to read the output of "ls -la" directly.

[narniat]

Because you don't write to stdout just by using it as a random pointer in some other API.

Excuse me I don't understand that... I also don't know why you gave that example, strcat is for concatenating two c strings, right?

[Salem]

You're the one who came up with the nonsense of passing stdout as the first parameter of fread.

[narniat]

Sorry now I've got it. That was a mistake in reading the manual. Thanks for pointing out it's nonesense.