finish basic builtin function

Author: chengscott

.gitignore

@@ -1 +1 @@
-source
+hw1

Makefile

@@ -1,13 +1,13 @@
 CC=gcc
-CFLAGS=-g
+CFLAGS=-O3 -Wall -static
 
 source: source.c builtin.c
-	cc ${CFLAGS} source.c builtin.c -o source
+	cc ${CFLAGS} source.c builtin.c -o hw1
 
 .PHONY: format
 format:
 	clang-format -style=Google -i *.c *.h
 
 .PHONY: clean
 clean:
-	rm -f source
+	rm -f hw1

builtin.c

@@ -1,4 +1,5 @@
 #include <dirent.h>
+#include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -39,6 +40,11 @@ const char *help_string[] = {
     "timestamp.",
     "umask {mode}:            Change the umask of the current session."};
 
+int set_euid_egid(int euid, int egid) {
+  if (setegid(egid) == -1) return -1;
+  return seteuid(euid);
+}
+
 const char *get_file_type(int mode) {
   const char *file_type[] = {"named pipe (fifo)",
                              "character special file",
@@ -199,20 +205,23 @@ int builtin_stat(char *line) {
   struct stat info;
   int ret = stat(arg, &info);
   // if (ret == -1)
+  char atime[N], mtime[N], ctime[N];
+  strftime(atime, N, "%F %T %z", localtime(&info.st_atime));
+  strftime(mtime, N, "%F %T %z", localtime(&info.st_mtime));
+  strftime(ctime, N, "%F %T %z", localtime(&info.st_ctime));
   printf(
       "\
   File: %s\n\
-  Size: %lld               Blocks: %lld          IO Block: %ld   %s\n\
-Device: %s      Inode: %ld   Links: %d\n\
-Access: (%lo)  Uid: (%ld)   Gid: (%ld)\n\
-Access: %s\
-Modify: %s\
-Change: %s",
+  Size: %ld               Blocks: %ld          IO Block: %ld   %s\n\
+Device: %lxh/%lud      Inode: %ld   Links: %lu\n\
+Access: (%u)  Uid: (%5u)   Gid: (%5u)\n\
+Access: %s\n\
+Modify: %s\n\
+Change: %s\n",
       arg, info.st_size, info.st_blocks, info.st_blksize,
-      get_file_type(info.st_mode & S_IFMT),
-      "",  // info.st_dev,
+      get_file_type(info.st_mode & S_IFMT), info.st_dev, info.st_dev,
       info.st_ino, info.st_nlink, info.st_mode & 0777, info.st_uid, info.st_gid,
-      ctime(&info.st_atime), ctime(&info.st_mtime), ctime(&info.st_ctime));
+      atime, mtime, ctime);
   return 0;
 }
 

builtin.h

@@ -21,3 +21,4 @@ const int (*builtin_func[])(char *) = {
     &builtin_exit,  &builtin_find,  &builtin_help,  &builtin_id,
     &builtin_mkdir, &builtin_pwd,   &builtin_rm,    &builtin_rmdir,
     &builtin_stat,  &builtin_touch, &builtin_unmask};
+int set_euid_egid(int, int);

source.c

@@ -19,9 +19,11 @@ int main(int argc, char **argv) {
 
 int arg_parse(int argc, char **argv) {
   if (argc == 3) {
-    int EUID = atoi(argv[1]);
-    int EGID = atoi(argv[2]);
-    // TBA change euid egid
+    int euid = atoi(argv[1]), egid = atoi(argv[2]);
+    if (set_euid_egid(euid, egid) == -1) {
+      fprintf(stderr, "Failed to set euid or egid.\n");
+      return -1;
+    }
     return 0;
   }
   fprintf(stderr, "Usage: %s {UID} {GID}\n", argv[0]);
@@ -33,7 +35,8 @@ void shell() {
   size_t len = 0;
   int eof = 0;
   do {
-    printf("~> ");
+    printf("\x1B[32m~\033[0m> ");
+    fflush(stdout);
     if ((eof = getline(&cmd, &len, stdin)) != -1) eof = shell_exec(cmd);
     // cleanup
     free(cmd);