From f0700effc02477ec4e2d2dd5b4f52bc4870aebc7 Mon Sep 17 00:00:00 2001
From: Alan Potteiger <alanpotteiger@gmail.com>
Date: Wed, 23 Nov 2022 00:52:27 +0100
Subject: [PATCH] `uname`!

---
 Makefile |  2 +-
 README   |  1 +
 uname.c  | 86 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 88 insertions(+), 1 deletion(-)
 create mode 100644 uname.c

diff --git a/Makefile b/Makefile
index 61ac29f..778cf5f 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-BIN=cat logname pwd sleep tty
+BIN=cat logname pwd sleep tty uname
 CFLAGS=-std=c99
 all: $(BIN)
 clean:
diff --git a/README b/README
index 497ed4f..ff6d855 100644
--- a/README
+++ b/README
@@ -15,6 +15,7 @@ Utilities
 - pwd
 - sleep
 - tty
+- uname
 
 License
 -------
diff --git a/uname.c b/uname.c
new file mode 100644
index 0000000..8ba5a73
--- /dev/null
+++ b/uname.c
@@ -0,0 +1,86 @@
+/* `uname.c` - return system name
+   Copyright (c) 2022, Alan Potteiger
+   See `LICENSE` for copyright and license details */
+
+#define _POSIX_C_SOURCE 200809L
+
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/utsname.h>
+
+static const char *usage = {
+	"usage: uname [-amnrsv]\n"
+};
+
+int
+main(int argc, char *argv[])
+{
+	struct utsname name;
+	int m, n, r, s, v;
+	char ch;
+
+	m = n = r = s = v = 0;
+
+	while ((ch = getopt(argc, argv, "amnrsv")) != -1) {
+		switch (ch) {
+		case 'a':
+			m = n = r = s = v = 1;
+			break;
+		case 'm':
+			m = 1;
+			break;
+		case 'n':
+			n = 1;
+			break;
+		case 'r':
+			r = 1;
+			break;
+		case 's':
+			s = 1;
+			break;
+		case 'v':
+			v = 1;
+			break;
+		case '?':
+		default:
+			fputs(usage, stderr);
+			return 1;
+		}
+	}
+
+	if (uname(&name) == -1) {
+		perror("uname");
+		return 1;
+	}
+
+	if (!(m || n || r || s || v))
+		s = 1;
+
+	if (m && n && r && s && v) {
+		printf(
+			"%s %s %s %s %s\n",
+			name.sysname, name.nodename, name.release,
+			name.version, name.machine
+		);
+
+		return 0;
+	}
+
+	/* I think this could be done better or more efficiently. I'm tired
+	   as hell though. I'll revisit this at some point */
+	if (s)
+		printf("%s ", name.sysname);
+	if (n)
+		printf("%s ", name.nodename);
+	if (r)
+		printf("%s ", name.release);
+	if (v)
+		printf("%s ", name.version);
+	if (m)
+		printf("%s ", name.machine);
+
+	puts("");
+
+	return 0;
+}
+
-- 
2.11.4.GIT