Simple implementation of tac (reverse cat)

tac.c

/* This is free and unencumbered software released into the public domain.
 * 
 * Anyone is free to copy, modify, publish, use, compile, sell, or
 * distribute this software, either in source code form or as a compiled
 * binary, for any purpose, commercial or non-commercial, and by any
 * means.
 * 
 * In jurisdictions that recognize copyright laws, the author or authors
 * of this software dedicate any and all copyright interest in the
 * software to the public domain. We make this dedication for the benefit
 * of the public at large and to the detriment of our heirs and
 * successors. We intend this dedication to be an overt act of
 * relinquishment in perpetuity of all present and future rights to this
 * software under copyright law.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 * 
 * For more information, please refer to <http://unlicense.org/> */


#include <sys/stat.h>

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

void tac(const char *file_name) 
{
	FILE *fp = fopen(file_name, "r");

	if (fp == NULL) {
		perror("Could not open file.\n");
		exit(EXIT_FAILURE);
	}

	int fd = fileno(fp);

	if (fd == -1) {
		perror("Could not get the file descriptor for file.\n");
		exit(EXIT_FAILURE);
	}

	struct stat buffer;

	int err = fstat(fd, &buffer);

	if (err == -1) {
		perror("Fstat returned an error.\n");
		exit(EXIT_FAILURE);
	}

	size_t file_size = buffer.st_size;
	char *reversed_file = (char*)malloc(sizeof(char) * file_size);

	file_size--;

	for (char ch = fgetc(fp); ch != EOF; ch = fgetc(fp), file_size--) 
		*(reversed_file + file_size) = ch;

	// Remove the newline at the start
	memmove(reversed_file, reversed_file + 1, strlen(reversed_file));

	printf("%s\n", reversed_file);

	fclose(fp);
	free(reversed_file);
}

int main(int argc, char* argv[])
{
	if (argc <= 1) {
		return EXIT_SUCCESS;
	}

	for (size_t i = 1; i < argc; i++) {
		tac(argv[i]);
	}
	
	return EXIT_SUCCESS;
}