ladybird/Userland/cat.cpp

#include <AK/Vector.h>
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

int main(int argc, char** argv)
{
    Vector<int> fds;
    if (argc > 1) {
        for (int i = 1; i < argc; i++) {
            int fd;
            if ((fd = open(argv[i], O_RDONLY)) == -1) {
                fprintf(stderr, "Failed to open %s: %s\n", argv[i], strerror(errno));
                continue;
            }
            fds.append(fd);
        }
    } else {
        fds.append(0);
    }
    for (auto& fd : fds) {
        for (;;) {
            char buf[32768];
            ssize_t nread = read(fd, buf, sizeof(buf));
            if (nread == 0)
                break;
            if (nread < 0) {
                perror("read");
                return 2;
            }
            ssize_t nwritten = write(1, buf, nread);
            if (nwritten < 0) {
                perror("write");
                return 3;
            }
            ASSERT(nwritten == nread);
        }
        close(fd);
    }
    return 0;
}