id: Add id.py

Author: Expertcoderz

src/id.py

@@ -0,0 +1,122 @@
+#!/usr/bin/python3
+
+import grp
+import pwd
+import os
+import sys
+from optparse import OptionParser
+
+
+def _id(opts, users: list[str]):
+    process_uid = os.getuid() if opts.real else os.geteuid()
+    process_gid = os.getgid() if opts.real else os.getegid()
+
+    failed = False
+
+    for user in users or [str(process_uid)]:
+        try:
+            passwd = pwd.getpwnam(user)
+        except KeyError as e:
+            try:
+                passwd = pwd.getpwuid(int(user))
+            except (KeyError, ValueError):
+                failed = True
+                print(e, file=sys.stderr)
+                continue
+
+        if opts.user:
+            print(
+                passwd.pw_name if opts.name else passwd.pw_uid,
+                end="\0" if opts.zero else "\n",
+            )
+            continue
+
+        gid = process_gid if passwd.pw_uid == process_uid else passwd.pw_gid
+
+        if opts.group:
+            print(
+                grp.getgrgid(gid) if opts.name else gid,
+                end="\0" if opts.zero else "\n",
+            )
+            continue
+
+        if opts.groups:
+            print(
+                ("\0" if opts.zero else "\n").join(
+                    map(str, os.getgrouplist(passwd.pw_name, gid))
+                ),
+                end="\0" if opts.zero else "\n",
+            )
+            continue
+
+        print(
+            f"uid={passwd.pw_uid}({passwd.pw_name})"
+            + f" gid={passwd.pw_gid}({grp.getgrgid(passwd.pw_gid).gr_name})"
+            + " groups="
+            + ",".join(
+                [
+                    f"{id}({grp.getgrgid(id).gr_name})"
+                    for id in os.getgrouplist(passwd.pw_name, passwd.pw_gid)
+                ]
+            ),
+        )
+
+    if failed:
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    parser = OptionParser(
+        usage="Usage: %prog [OPTION]... [USER]...",
+        description="Print user and group information for each USER or the current user.",
+        add_help_option=False,
+    )
+    parser.add_option("--help", action="help", help="show usage information and exit")
+
+    parser.add_option(
+        "-u", "--user", action="store_true", help="print only the effective user ID"
+    )
+    parser.add_option(
+        "-g", "--group", action="store_true", help="print only the effective group ID"
+    )
+    parser.add_option("-G", "--groups", action="store_true", help="print all group IDs")
+
+    parser.add_option(
+        "-n",
+        "--name",
+        action="store_true",
+        help="print names instead of numbers (for -ugG)",
+    )
+    parser.add_option(
+        "-r",
+        "--real",
+        action="store_true",
+        help="print the real ID instead of the effective ID (for -ugG)",
+    )
+    parser.add_option(
+        "-z",
+        "--zero",
+        action="store_true",
+        help="delimit entries with NUL instead of whitespace (for -ugG)",
+    )
+
+    parser.add_option(
+        "-a", action="store_true", help="(ignored; present for compatibility)"
+    )
+    parser.add_option("-Z", "--context", action="store_true", help="(unimplemented)")
+
+    opts, args = parser.parse_args()
+
+    if opts.context:
+        parser.error("--context (-Z) is not supported")
+
+    if (ugG := (opts.user, opts.group, opts.groups)).count(True) > 1:
+        parser.error("cannot print more than one of -ugG")
+
+    if opts.name or opts.real and not any(ugG):
+        parser.error("cannot print only names or real IDs in default format")
+
+    if opts.zero and not any(ugG):
+        parser.error("option --zero not permitted in default format")
+
+    _id(opts, args)