ls.c

#include "types.h"
#include "stat.h"
#include "user.h"
#include "fs.h"

char *
fmtname(char *path) {
    static char buf[DIRSIZ + 1];
    char *p;

    // Find first character after last slash.
    for (p = path + strlen(path); p >= path && *p != '/'; p--);
    p++;

    // Return blank-padded name.
    if (strlen(p) >= DIRSIZ)
        return p;
    memmove(buf, p, strlen(p));
    memset(buf + strlen(p), ' ', DIRSIZ - strlen(p));
    return buf;
}

void
ls(char *path) {
    char buf[512], *p;
    int fd;
    struct dirent de;
    struct stat st;

    if ((fd = open(path, 0)) < 0) {
        printf(2, "ls: cannot open %s\n", path);
        return;
    }

    if (fstat(fd, &st) < 0) {
        printf(2, "ls: cannot stat %s\n", path);
        close(fd);
        return;
    }

    switch (st.type) {
        case T_FILE:
            printf(1, "%s %d %d %d\n", fmtname(path), st.type, st.ino, st.size);
            break;

        case T_DIR:
            if (strlen(path) + 1 + DIRSIZ + 1 > sizeof buf) {
                printf(1, "ls: path too long\n");
                break;
            }
            strcpy(buf, path);
            p = buf + strlen(buf);
            *p++ = '/';
            while (read(fd, &de, sizeof(de)) == sizeof(de)) {
                if (de.inum == 0)
                    continue;
                memmove(p, de.name, DIRSIZ);
                p[DIRSIZ] = 0;
                if (stat(buf, &st) < 0) {
                    printf(1, "ls: cannot stat %s\n", buf);
                    continue;
                }
                printf(1, "%s %d %d %d\n", fmtname(buf), st.type, st.ino, st.size);
            }
            break;
    }
    close(fd);
}

int
main(int argc, char *argv[]) {
    int i;

    if (argc < 2) {
        ls(".");
        exit();
    }
    for (i = 1; i < argc; i++)
        ls(argv[i]);
    exit();
}