From a45985af915d93cb8a340b8429725e9756472b80 Mon Sep 17 00:00:00 2001
From: jewelcodes <omarmelghoul01@gmail.com>
Date: Sat, 5 Oct 2024 19:50:28 -0400
Subject: [PATCH] ls: implementation of the ls command

---
 ls/ls.c | 173 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 172 insertions(+), 1 deletion(-)

diff --git a/ls/ls.c b/ls/ls.c
index c4a8c62..1cb9214 100644
--- a/ls/ls.c
+++ b/ls/ls.c
@@ -5,8 +5,179 @@
  * ls: Implementation of the ls command
  */
 
+#include <unistd.h>
+#include <limits.h>
+#include <string.h>
 #include <stdio.h>
+#include <dirent.h>
+#include <sys/stat.h>
+
+int h = 0, l = 0, a = 0;
+
+char cwdbuf[PATH_MAX];
+
+int statDump(char *name, char *path, struct stat *st) {
+    if(!a && path[0] == '.') return 0;
+
+    char color[8];
+    char reset[] = "\e[0m";
+    char buffer[PATH_MAX];
+
+    if(S_ISCHR(st->st_mode))
+        sprintf(color, "\e[0;93m");
+    else if(S_ISDIR(st->st_mode))
+        sprintf(color, "\e[0;96m");
+    else if(S_ISBLK(st->st_mode))
+        sprintf(color, "\e[0;91m");
+    else if(S_ISLNK(st->st_mode))
+        sprintf(color, "\e[0;95m");
+    else if(st->st_mode & S_IXUSR || st->st_mode & S_IXGRP || st->st_mode & S_IXOTH)
+        sprintf(color, "\e[0;92m");
+    else
+        sprintf(color, "%s", reset);
+
+    if(l) {
+        // detailed listing
+        sprintf(buffer, "%s", reset);
+        
+        // file type
+        if(S_ISCHR(st->st_mode)) sprintf(buffer+strlen(buffer), "c");
+        else if(S_ISDIR(st->st_mode)) sprintf(buffer+strlen(buffer), "d");
+        else if(S_ISBLK(st->st_mode)) sprintf(buffer+strlen(buffer), "b");
+        else if(S_ISLNK(st->st_mode)) sprintf(buffer+strlen(buffer), "l");
+        else sprintf(buffer+strlen(buffer), "-");
+
+        // permissions
+        if(st->st_mode & S_IRUSR) sprintf(buffer+strlen(buffer), "r");
+        else sprintf(buffer+strlen(buffer), "-");
+
+        if(st->st_mode & S_IWUSR) sprintf(buffer+strlen(buffer), "w");
+        else sprintf(buffer+strlen(buffer), "-");
+
+        if(st->st_mode & S_IXUSR) sprintf(buffer+strlen(buffer), "x");
+        else sprintf(buffer+strlen(buffer), "-");
+
+        if(st->st_mode & S_IRGRP) sprintf(buffer+strlen(buffer), "r");
+        else sprintf(buffer+strlen(buffer), "-");
+
+        if(st->st_mode & S_IWGRP) sprintf(buffer+strlen(buffer), "w");
+        else sprintf(buffer+strlen(buffer), "-");
+
+        if(st->st_mode & S_IXGRP) sprintf(buffer+strlen(buffer), "x");
+        else sprintf(buffer+strlen(buffer), "-");
+
+        if(st->st_mode & S_IROTH) sprintf(buffer+strlen(buffer), "r");
+        else sprintf(buffer+strlen(buffer), "-");
+
+        if(st->st_mode & S_IWOTH) sprintf(buffer+strlen(buffer), "w");
+        else sprintf(buffer+strlen(buffer), "-");
+
+        if(st->st_mode & S_IXOTH) sprintf(buffer+strlen(buffer), "x");
+        else sprintf(buffer+strlen(buffer), "-");
+
+        sprintf(buffer+strlen(buffer), "  ");
+
+        // owner and group UIDs
+        if(!st->st_uid) sprintf(buffer+strlen(buffer), "root  ");
+        else sprintf(buffer+strlen(buffer), "%04X ", st->st_uid);
+
+        if(!st->st_gid) sprintf(buffer+strlen(buffer), "root  ");
+        else sprintf(buffer+strlen(buffer), "%04X ", st->st_gid);
+
+        if(h) {
+            // human-readable sizes (MB, GB, etc)
+            if(st->st_size >= 0x40000000)
+                sprintf(buffer+strlen(buffer), "%6dG  ", st->st_size / 0x40000000);
+            else if(st->st_size >= 0x100000)
+                sprintf(buffer+strlen(buffer), "%6dM  ", st->st_size / 0x100000);
+            else if(st->st_size > 4096)
+                sprintf(buffer+strlen(buffer), "%6dk  ", st->st_size / 1024);
+            else
+                sprintf(buffer+strlen(buffer), "%7d  ", st->st_size);
+        } else {
+            // default sizes (bytes)
+            sprintf(buffer+strlen(buffer), "%9d  ", st->st_size);
+        }
+
+        sprintf(buffer+strlen(buffer), "%s%s%s\n", color, path, reset);
+        printf("%s", buffer);
+    } else {
+        // undetailed
+        printf("%s%s%s\n", color, path, reset);
+    }
+
+    return 0;
+}
+
+int dir(char *name, char *parent) {
+    DIR *dir = opendir(parent);
+    if(!dir) {
+        fprintf(stderr, "%s: could not open directory %s\n", name, parent);
+        return 1;
+    }
+
+    int errors = 0;
+    char buffer[PATH_MAX];
+    struct dirent *entry;
+    struct stat st;
+
+    while((entry = readdir(dir))) {
+        sprintf(buffer, "%s/%s", parent, entry->d_name);
+        if(stat(buffer, &st)) {
+            fprintf(stderr, "%s: could not stat %s\n", name, buffer);
+            errors++;
+        } else {
+            errors += statDump(name, entry->d_name, &st);
+        }
+    }
+
+    closedir(dir);
+    return errors;
+}
+
+int ls(char *name, char *path) {
+    // determine if this is a file or directory
+    struct stat st;
+    if(stat(path, &st)) {
+        fprintf(stderr, "%s: could not stat %s\n", name, path);
+        return 1;
+    }
+
+    if(S_ISDIR(st.st_mode)) return dir(name, path);
+
+    return statDump(name, path, &st);
+}
 
 int main(int argc, char **argv) {
-    return 0;   // TODO
+    opterr = 0;
+    int opt;
+    while((opt = getopt(argc, argv, "hal")) != -1) {
+        switch(opt) {
+        case 'h': h = 1; break;
+        case 'a': a = 1; break;
+        case 'l': l = 1; break;
+        case '?':
+            fprintf(stderr, "%s: invalid option -- %c\n", argv[0], optopt);
+            fprintf(stderr, "usage: %s [-hal] [file ...]\n", argv[0]);
+            return -1;
+        }
+    }
+
+    int retval = 0;
+
+    if(optind < argc) {
+        for(int i = optind; i < argc; i++) {
+            retval += ls(argv[0], argv[i]);
+        }
+    } else {
+        char *cwd = getcwd(cwdbuf, PATH_MAX);
+        if(cwd) {
+            retval = ls(argv[0], cwd);
+        } else {
+            fprintf(stderr, "%s: could not get current directory\n", argv[0]);
+            retval = 1;
+        }
+    }
+
+    return retval;
 }
\ No newline at end of file