1 files changed, 67 insertions, 0 deletions
diff --git a/src/uname.c b/src/uname.c
new file mode 100644
index 0000000..0fbef58
--- /dev/null
+++ b/src/uname.c
@@ -0,0 +1,67 @@
+#define _POSIX_C_SOURCE 2
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <sys/utsname.h>
+
+enum name
+{
+	NAME_SYSNAME  = 1 << 0,
+	NAME_NODENAME = 1 << 1,
+	NAME_RELEASE  = 1 << 2,
+	NAME_VERSION  = 1 << 3,
+	NAME_MACHINE  = 1 << 4,
+	NAME_ALL      = NAME_SYSNAME | NAME_NODENAME | NAME_RELEASE | NAME_VERSION | NAME_MACHINE,
+};
+
+static void print_name(char *name)
+{
+	static bool previous = false;
+	if (previous)
+		fputc(' ' ,stdout);
+	else
+		previous = true;
+	fputs(name, stdout);
+}
+
+int main(int argc, char *argv[])
+{
+	enum name names = 0;
+	int option;
+	while ((option = getopt(argc, argv, "amnrsv")) != -1)
+	{
+		switch (option)
+		{
+			case 'a': names |= NAME_ALL; break;
+			case 'm': names |= NAME_MACHINE; break;
+			case 'n': names |= NAME_NODENAME; break;
+			case 'r': names |= NAME_RELEASE; break;
+			case 's': names |= NAME_SYSNAME; break;
+			case 'v': names |= NAME_VERSION; break;
+		}
+	}
+	if (optind != argc)
+	{
+		fprintf(stderr, "%s: extra operand '%s'\n", argv[0], argv[optind]);
+		exit(1);
+	}
+	if (names == 0)
+		names = NAME_SYSNAME;
+
+	struct utsname names_buf;
+	uname(&names_buf);
+
+	if (names & NAME_SYSNAME)
+		print_name(names_buf.sysname);
+	if (names & NAME_NODENAME)
+		print_name(names_buf.nodename);
+	if (names & NAME_RELEASE)
+		print_name(names_buf.release);
+	if (names & NAME_VERSION)
+		print_name(names_buf.version);
+	if (names & NAME_MACHINE)
+		print_name(names_buf.machine);
+	fputc('\n', stdout);
+	return 0;
+}