commit 28129a87c4db31cd43f0e4289e68587f2a01127e
parent fb11173926bc783bc70b8e848368eaa97915e54f
Author: Mattias Andrée <maandree@kth.se>
Date: Sat, 26 Mar 2016 17:23:03 +0100
Add rev(1)
Signed-off-by: Mattias Andrée <maandree@kth.se>
Diffstat:
| M | Makefile | | | 1 | + |
| M | README | | | 1 | + |
| A | rev.1 | | | 22 | ++++++++++++++++++++++ |
| A | rev.c | | | 74 | ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
4 files changed, 98 insertions(+), 0 deletions(-)
diff --git a/Makefile b/Makefile
@@ -137,6 +137,7 @@ BIN =\
pwd\
readlink\
renice\
+ rev\
rm\
rmdir\
sed\
diff --git a/README b/README
@@ -66,6 +66,7 @@ The following tools are implemented:
0=*|o pwd .
0=*|x readlink .
0=*|o renice .
+0#* x rev .
0=*|o rm (-i)
0=*|o rmdir .
# sed .
diff --git a/rev.1 b/rev.1
@@ -0,0 +1,22 @@
+.Dd 2016-03-26
+.Dt REV 1
+.Os sbase
+.Sh NAME
+.Nm rev
+.Nd reverse each line
+.Sh SYNOPSIS
+.Nm
+.Op Ar file ...
+.Sh DESCRIPTION
+.Nm
+reads each
+.Ar file
+in sequence and writes it to stdout, but
+with all characters in each line in reverse
+order. If no
+.Ar file
+is given
+.Nm
+reads from stdin.
+.Sh SEE ALSO
+.Xr tac 1
diff --git a/rev.c b/rev.c
@@ -0,0 +1,74 @@
+/* See LICENSE file for copyright and license details. */
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "text.h"
+#include "util.h"
+
+static void
+usage(void)
+{
+ eprintf("usage: %s [file ...]\n", argv0);
+}
+
+static void
+rev(FILE *fp)
+{
+ static char *line = NULL;
+ static size_t size = 0;
+ size_t i;
+ ssize_t n;
+ int lf;
+
+ while ((n = getline(&line, &size, fp)) > 0) {
+ lf = n && line[n - 1] == '\n';
+ i = n -= lf;
+ for (n = 0; i--;) {
+ if ((line[i] & 0xC0) == 0x80) {
+ n++;
+ } else {
+ fwrite(line + i, 1, n + 1, stdout);
+ n = 0;
+ }
+ }
+ if (n)
+ fwrite(line, 1, n, stdout);
+ if (lf)
+ fputc('\n', stdout);
+ }
+}
+
+int
+main(int argc, char *argv[])
+{
+ FILE *fp;
+ int ret = 0;
+
+ ARGBEGIN {
+ default:
+ usage();
+ } ARGEND
+
+ if (!argc) {
+ rev(stdin);
+ } else {
+ for (; *argv; argc--, argv++) {
+ if (!strcmp(*argv, "-")) {
+ *argv = "<stdin>";
+ fp = stdin;
+ } else if (!(fp = fopen(*argv, "r"))) {
+ weprintf("fopen %s:", *argv);
+ ret = 1;
+ continue;
+ }
+ rev(fp);
+ if (fp != stdin && fshut(fp, *argv))
+ ret = 1;
+ }
+ }
+
+ ret |= fshut(stdin, "<stdin>") | fshut(stdout, "<stdout>");
+
+ return ret;
+}
