Hi Rob, hello world,
In attachment you can find an implementation of 'rev' including tests.
As far as I know it's included in posix, nor lsb but it lives in
util-linux and busybox also has it.
edb@lapedb:~/edb-stuff/toybox/toybox$ echo "abc" | rev
cba
edb@lapedb:~/edb-stuff/toybox/toybox$ echo -en "abc\ndef" | rev
cba
fed
edb@lapedb:~/edb-stuff/toybox/toybox$ echo "abc" | ./toybox rev
cba
edb@lapedb:~/edb-stuff/toybox/toybox$ echo -en "abc\ndef" | ./toybox rev
cba
fed
I just wrote it because it was rather easy and I bumped into it while
looking at tac yesterday, btw it also suffers from the /dev/full bug
since it also uses xputs.
gr
E.
--
Elie De Brauwer
# HG changeset patch
# User Elie De Brauwer <[email protected]>
# Date 1355657475 -3600
# Node ID 0305ce03173f4e077cc35e84e25d18f90cd3554c
# Parent 4bccd66ab0daccacd902821f97e8f8bbf4ff6ef9
Adding implementation of rev including tests
diff -r 4bccd66ab0da -r 0305ce03173f scripts/test/rev.test
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/scripts/test/rev.test Sun Dec 16 12:31:15 2012 +0100
@@ -0,0 +1,25 @@
+#!/bin/bash
+
+[ -f testing.sh ] && . testing.sh
+
+#testing "name" "command" "result" "infile" "stdin"
+
+echo -e "one" > file1
+echo -e "two" > file2
+testing "rev" "rev && echo yes" "orez\nyes\n" "" "zero\n"
+testing "rev -" "rev - && echo yes" "orez\nyes\n" "" "zero\n"
+testing "rev file1 file2" "rev file1 file2" "eno\nowt\n" "" ""
+testing "rev - file" "rev - file1" "orez\neno\n" "" "zero\n"
+testing "rev file -" "rev file1 -" "eno\norez\n" "" "zero\n"
+testing "rev no trailing newline" "rev -" "cba\nfed\n" "" "abc\ndef"
+
+testing "rev file1 notfound file2" \
+ "rev file1 notfound file2 2>stderr && echo ok ; cat stderr; rm stderr" \
+ "eno\nowt\nrev: notfound: No such file or directory\n" "" ""
+
+testing "rev different input sizes"\
+ "rev"\
+ "\n1\n21\n321\n4321\n54321\n4321\n321\n21\n1\n\n"\
+ "" "\n1\n12\n123\n1234\n12345\n1234\n123\n12\n1\n\n"
+
+rm file1 file2
\ No newline at end of file
diff -r 4bccd66ab0da -r 0305ce03173f toys/other/rev.c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/toys/other/rev.c Sun Dec 16 12:31:15 2012 +0100
@@ -0,0 +1,44 @@
+/* rev.c - reverse lines of a set of given input files
+ *
+ * Copyright 2012 Elie De Brauwer <[email protected]>
+
+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);
+}
_______________________________________________
Toybox mailing list
[email protected]
http://lists.landley.net/listinfo.cgi/toybox-landley.net
