id: support numeric lookup.

Fall back to converting the "name" to an integer and calling getpwuid().
We need to update `username` for the later call to getgrouplist().

Also fix the separator printing logic to avoid a trailing ',' on `id 0`.

Switch to FLAG() and move some declarations down to where they can be
initialized, both for clarity.

Also add simple tests. Sadly, there's no always-present user that is in
multiple groups.

1 files changed, 10 insertions, 0 deletions

diff --git a/tests/id.test b/tests/id.test
new file mode 100755
index 00000000..6d0f63a8
--- /dev/null
+++ b/tests/id.test
@@ -0,0 +1,10 @@
+#!/bin/bash
+
+[ -f testing.sh ] && . testing.sh
+
+#testing "name" "command" "result" "infile" "stdin"
+
+testing "id 0" "id 0" "uid=0(root) gid=0(root) groups=0(root)\n" "" ""
+testing "id root" "id root" "uid=0(root) gid=0(root) groups=0(root)\n" "" ""
+testing "id no-such-user" "id no-such-user 2>/dev/null ; echo \$?" "1\n" "" ""
+testing "id 9999999" "id 9999999 2>/dev/null ; echo \$?" "1\n" "" ""