From 09c279285ac44ada82c792d88fb246fd98a14e03 Mon Sep 17 00:00:00 2001
From: FRIGN <dev@frign.de>
Date: Mon, 14 Dec 2015 10:55:25 +0100
Subject: [PATCH] Add whoami(1)

including manpage and other stuff. This program is a no-brainer.
This was inspired by an initial commit by e@bestmx.net. Thanks!
---
 Makefile |  1 +
 README   |  1 +
 whoami.1 |  9 +++++++++
 whoami.c | 37 +++++++++++++++++++++++++++++++++++++
 4 files changed, 48 insertions(+)
 create mode 100644 whoami.1
 create mode 100644 whoami.c

diff --git a/Makefile b/Makefile
index c2d8266..0c73d68 100644
--- a/Makefile
+++ b/Makefile
@@ -157,6 +157,7 @@ BIN =\
 	uuencode\
 	wc\
 	which\
+	whoami\
 	xargs\
 	yes
 
diff --git a/README b/README
index 86287b7..aff0644 100644
--- a/README
+++ b/README
@@ -95,6 +95,7 @@ The following tools are implemented:
 =*|o uuencode    .
 #*|o wc          .
 =*|x which       .
+=*|x whoami      .
 =*|o xargs       (-p)
 =*|x yes         .
 
diff --git a/whoami.1 b/whoami.1
new file mode 100644
index 0000000..535c927
--- /dev/null
+++ b/whoami.1
@@ -0,0 +1,9 @@
+.Dd 2015-12-14
+.Dt WHOAMI 1
+.Os sbase
+.Sh NAME
+.Nm whoami
+.Nd show effective uid
+.Sh SYNOPSIS
+.Nm
+writes the name of the effective uid to stdout.
diff --git a/whoami.c b/whoami.c
new file mode 100644
index 0000000..4d88aea
--- /dev/null
+++ b/whoami.c
@@ -0,0 +1,37 @@
+/* See LICENSE file for copyright and license details. */
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <pwd.h>
+
+#include "util.h"
+
+static void
+usage (void)
+{
+	eprintf("usage: %s\n", argv0);
+}
+
+int
+main (int argc, char *argv[])
+{
+	uid_t uid;
+	struct passwd *pw;
+
+	argv0 = argv[0], argc--, argv++;
+
+	if (argc)
+		usage();
+
+	uid = geteuid();
+	errno = 0;
+	if (!(pw = getpwuid(uid))) {
+		if (errno)
+			eprintf("getpwuid %d:", uid);
+		else
+			eprintf("getpwuid %d: no such user\n", uid);
+	}
+	puts(pw->pw_name);
+
+	return fshut(stdout, "<stdout>");
+}