Adding implementation of rev including tests

1 files changed, 44 insertions, 0 deletions

diff --git a/toys/other/rev.c b/toys/other/rev.c
new file mode 100644
index 00000000..a95d6615
--- /dev/null
+++ b/toys/other/rev.c
@@ -0,0 +1,44 @@
+/* rev.c - reverse lines of a set of given input files
+ *
+ * Copyright 2012 Elie De Brauwer <eliedebrauwer@gmail.com>
+
+USE_REV(NEWTOY(rev, NULL, TOYFLAG_USR|TOYFLAG_BIN))
+
+config REV
+  bool "rev"
+  default y
+  help
+    usage: rev [FILE...]
+
+    Output lines reversed, when no files are given stdin is used.
+*/
+
+#include "toys.h"
+
+void do_rev(int fd, char *name)
+{
+  char *c;
+
+  for (;;) {
+    int len;
+    int i;
+    if (!(c = get_line(fd))) break;
+    len = strlen(c) - 1;
+    i = 0;
+    while ( i <= len/2)
+    {
+      char tmp;
+      tmp = c[i];
+      c[i] = c[len-i];
+      c[len-i] = tmp;
+      i++;
+    }
+    xputs(c);
+    free(c);
+  }
+}
+
+void rev_main(void)
+{
+  loopfiles(toys.optargs, do_rev);
+}