data.esc

#include <stdio.h>$
#include <stdlib.h>$
#include <unistd.h>$
#include <sys/types.h>$
#include <sys/stat.h>$
#include <fcntl.h>$
$
static void do_cat(const char *path);$
static void die(const char *s);$
$
int$
main(int argc, char *argv[])$
{$
    int i;$
$
    if (argc < 2) {$
\tfprintf(stderr, "%s: file name not given\n", argv[0]);$
\texit(1);$
    }$
    for (i = 1; i < argc; i++) {$
\tdo_cat(argv[i]);$
    }$
    exit(0);$
}$
$
#define BUFFER_SIZE 2048$
$
static void$
do_cat(const char *path)$
{$
    int fd;$
    unsigned char buf[BUFFER_SIZE];$
    int n;$
$
    fd = open(path, O_RDONLY);$
    if (fd < 0) die(path);$
    for (;;) {$
\tn = read(fd, buf, sizeof buf);$
\tif (n < 0) die(path);$
\tif (n == 0) break;$
\tif (write(STDOUT_FILENO, buf, n) < 0) die(path);$
    }$
    if (close(fd) < 0) die(path);$
}$
$
static void$
die(const char *s)$
{$
    perror(s);$
    exit(1);$
}