Luna/apps/src/stat.c

#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>

const char* mode_to_string(mode_t mode)
{
    static char mode_string[12];

    char mode_set[12] = {'s', 'g', 'r', 'w', 'x', 'r', 'w', 'x', 'r', 'w', 'x', 0};
    mode_t mode_val[12] = {S_ISUID, S_ISGID, S_IRUSR, S_IWUSR, S_IXUSR, S_IRGRP,
                           S_IWGRP, S_IXGRP, S_IROTH, S_IWOTH, S_IXOTH, S_IFMT};

    for (int i = 0; i < 12; i++)
    {
        if (mode & mode_val[i]) mode_string[i] = mode_set[i];
        else
            mode_string[i] = '-';
    }

    return mode_string;
}

int main(int argc, char** argv)
{
    if (argc == 1)
    {
        fprintf(stderr, "Usage: stat [file]\n");
        return EXIT_FAILURE;
    }

    struct stat st;
    if (stat(argv[1], &st) < 0)
    {
        perror("stat");
        return EXIT_FAILURE;
    }

    printf("Type: ");

    switch (st.st_mode & S_IFMT)
    {
    case S_IFREG: puts("Regular file"); break;
    case S_IFDIR: puts("Directory"); break;
    case S_IFCHR: puts("Character device"); break;
    default: puts("Unknown"); break;
    }

    struct passwd* own = getpwuid(st.st_uid);

    printf("Length: %ld\n", st.st_size);
    printf("Inode: %ld\n", st.st_ino);
    if (!own) printf("Owned by: UID %d\n", st.st_uid);
    else
        printf("Owned by: %s\n", own->pw_name);
    printf("Mode: %s\n", mode_to_string(st.st_mode));

    endpwent();

    return EXIT_SUCCESS;
}