now version controlled.

1 files changed, 48 insertions, 0 deletions

diff --git a/rev.c b/rev.c
new file mode 100644
index 0000000..6120477
--- /dev/null
+++ b/rev.c
@@ -0,0 +1,48 @@
+#include <u.h>
+#include <libc.h>
+
+void
+swap(char *a, char *b)
+{
+	char tmp;
+
+	tmp = *a;
+	*a = *b;
+	*b = tmp;
+}
+
+void
+rev(char *s, ulong len)
+{
+	char *e;
+
+	e = s+len;
+	while(s < e)
+		swap(s++, --e);
+}
+
+void
+usage(void)
+{
+	fprint(2, "usage: %s text ...\n", argv0);
+	exits("usage");
+}
+
+void
+main(int argc, char *argv[])
+{
+	int first;
+
+	first = 1;
+	ARGBEGIN{
+	default: usage();
+	}ARGEND;
+	if(argc < 1)
+		usage();
+	while(argc--){
+		rev(argv[argc], strlen(argv[argc]));
+		print(first ? first--, "%s" : " %s", argv[argc]);
+	}
+	print("\n");
+	exits(nil);
+}