userland(ls): add -l option

userland/ls.c

@@ -1,108 +1,172 @@
 #include <dirent.h>
 #include <errno.h>
-#include <extra.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/ioctl.h>
+#include <sys/limits.h>
 #include <sys/stat.h>
+#include <sys/sysmacros.h>
 #include <unistd.h>
 
-static int get_format(const struct dirent* dent, const char** out_format,
-                      size_t* out_len) {
-    struct stat stat_buf;
-    if (stat(dent->d_name, &stat_buf) < 0) {
-        perror("stat");
-        return -1;
-    }
-    switch (stat_buf.st_mode & S_IFMT) {
+static const char* get_format(const char* name, mode_t mode, size_t* out_len) {
+    switch (mode & S_IFMT) {
     case S_IFDIR:
-        *out_format = "\x1b[01;34m%s\x1b[m/";
-        *out_len = strlen(dent->d_name) + 1;
-        break;
+        *out_len = strlen(name) + 1;
+        return "\x1b[01;34m%s\x1b[m/";
     case S_IFCHR:
     case S_IFBLK:
-        *out_format = "\x1b[01;33m%s\x1b[m";
-        *out_len = strlen(dent->d_name);
-        break;
+        *out_len = strlen(name);
+        return "\x1b[01;33m%s\x1b[m";
     case S_IFIFO:
-        *out_format = "\x1b[33m%s\x1b[m|";
-        *out_len = strlen(dent->d_name) + 1;
-        break;
+        *out_len = strlen(name) + 1;
+        return "\x1b[33m%s\x1b[m|";
     case S_IFLNK:
-        *out_format = "\x1b[01;36m%s\x1b[m@";
-        *out_len = strlen(dent->d_name) + 1;
-        break;
+        *out_len = strlen(name) + 1;
+        return "\x1b[01;36m%s\x1b[m@";
     case S_IFSOCK:
-        *out_format = "\x1b[01;35m%s\x1b[m=";
-        *out_len = strlen(dent->d_name) + 1;
-        break;
+        *out_len = strlen(name) + 1;
+        return "\x1b[01;35m%s\x1b[m=";
     case S_IFREG:
     default:
-        if (stat_buf.st_mode & S_IXUSR) {
-            *out_format = "\x1b[01;32m%s\x1b[m*";
-            *out_len = strlen(dent->d_name) + 1;
+        if (mode & S_IXUSR) {
+            *out_len = strlen(name) + 1;
+            return "\x1b[01;32m%s\x1b[m*";
         } else {
-            *out_format = "%s";
-            *out_len = strlen(dent->d_name);
+            *out_len = strlen(name);
+            return "%s";
         }
-        break;
     }
-    return 0;
+}
+
+static char get_file_type_char(mode_t mode) {
+    switch (mode & S_IFMT) {
+    case S_IFDIR:
+        return 'd';
+    case S_IFCHR:
+        return 'c';
+    case S_IFBLK:
+        return 'b';
+    case S_IFIFO:
+        return 'p';
+    case S_IFLNK:
+        return 'l';
+    case S_IFSOCK:
+        return 's';
+    case S_IFREG:
+    default:
+        return '-';
+    }
 }
 
 #define TAB_STOP 8
 
-int main(int argc, char* argv[]) {
-    const char* path;
-    if (argc < 2) {
-        static char path_buf[1024];
-        getcwd(path_buf, 1024);
-        path = path_buf;
-    } else if (argc == 2) {
-        path = argv[1];
-    } else {
-        dprintf(STDERR_FILENO, "Usage: ls [DIRECTORY]\n");
-        return EXIT_FAILURE;
-    }
+static int list_dir(const char* path, size_t terminal_width, bool long_format) {
+    int ret = -1;
+    DIR* dirp = NULL;
 
-    DIR* dirp = opendir(path);
+    dirp = opendir(path);
     if (!dirp) {
         perror("opendir");
-        return EXIT_FAILURE;
+        goto fail;
     }
-    chdir(path);
 
-    size_t width = 0;
+    size_t path_len = strlen(path);
+    size_t x_pos = 0;
     for (;;) {
         errno = 0;
         struct dirent* dent = readdir(dirp);
         if (!dent) {
             if (errno == 0)
                 break;
             perror("readdir");
-            closedir(dirp);
-            return EXIT_FAILURE;
+            goto fail;
         }
 
-        const char* format;
-        size_t len;
-        if (get_format(dent, &format, &len) < 0) {
-            closedir(dirp);
-            return EXIT_FAILURE;
+        size_t name_len = strlen(dent->d_name);
+        char* full_path = malloc(path_len + 1 + name_len + 1);
+        if (!full_path) {
+            perror("malloc");
+            goto fail;
+        }
+        strcpy(full_path, path);
+        full_path[path_len] = '/';
+        strcpy(full_path + path_len + 1, dent->d_name);
+
+        struct stat st;
+        ret = stat(full_path, &st);
+        free(full_path);
+        if (ret < 0) {
+            perror("stat");
+            goto fail;
         }
-        size_t next_pos = round_up(width + len + 1, TAB_STOP);
-        if (next_pos >= 80) {
-            width = round_up(len + 1, TAB_STOP);
+
+        size_t len;
+        const char* format = get_format(dent->d_name, st.st_mode, &len);
+        if (long_format) {
+            if (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode)) {
+                printf("%c %3d,%6d ", get_file_type_char(st.st_mode),
+                       major(st.st_rdev), minor(st.st_rdev));
+            } else {
+                printf("%c %10u ", get_file_type_char(st.st_mode), st.st_size);
+            }
+            printf(format, dent->d_name);
             putchar('\n');
         } else {
-            width = next_pos;
+            size_t next_pos = round_up(x_pos + len + 1, TAB_STOP);
+            if (next_pos >= terminal_width) {
+                x_pos = round_up(len + 1, TAB_STOP);
+                putchar('\n');
+            } else {
+                x_pos = next_pos;
+            }
+            printf(format, dent->d_name);
+            putchar('\t');
         }
-        printf(format, dent->d_name);
-        putchar('\t');
     }
-    if (width > 0)
+    if (x_pos > 0)
         putchar('\n');
 
-    closedir(dirp);
-    return EXIT_SUCCESS;
+    ret = 0;
+fail:
+    putchar('\n');
+    if (dirp)
+        closedir(dirp);
+    return ret;
+}
+
+int main(int argc, char* argv[]) {
+    bool long_format = false;
+    size_t num_dirs = 0;
+    for (int i = 1; i < argc; i++) {
+        if (!strcmp(argv[i], "-l"))
+            long_format = true;
+        else
+            ++num_dirs;
+    }
+
+    size_t terminal_width = 80;
+    struct winsize winsize;
+    if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &winsize) >= 0)
+        terminal_width = winsize.ws_col;
+
+    if (num_dirs == 0) {
+        static char path_buf[PATH_MAX];
+        getcwd(path_buf, PATH_MAX);
+        if (list_dir(path_buf, terminal_width, long_format) < 0)
+            return EXIT_FAILURE;
+        return EXIT_SUCCESS;
+    }
+
+    int ret = EXIT_SUCCESS;
+    for (int i = 1; i < argc; i++) {
+        const char* arg = argv[i];
+        if (!strcmp(arg, "-l"))
+            continue;
+        if (num_dirs > 1)
+            printf("%s:\n", arg);
+        if (list_dir(arg, terminal_width, long_format) < 0)
+            ret = EXIT_FAILURE;
+    }
+    return ret;
 }