sbase

suckless unix tools
git clone git://git.2f30.org/sbase.git
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commit 28129a87c4db31cd43f0e4289e68587f2a01127e
parent fb11173926bc783bc70b8e848368eaa97915e54f
Author: Mattias Andrée <maandree@kth.se>
Date:   Sat Mar 26 17:23:03 +0100

Add rev(1)

Signed-off-by: Mattias Andrée <maandree@kth.se>

Diffstat:
Makefile | 1+
README | 1+
rev.1 | 22++++++++++++++++++++++
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; +}