README
======
-coloredstderr is a small library which uses 'LD_PRELOAD' to color stderr.
-
+coloredstderr is a small library which uses 'LD_PRELOAD' to color stderr. It
+``follows'' dups, has minimal performance overhead and can ignore certain
+binaries.
Like all solutions using 'LD_PRELOAD' it only works with dynamically linked
binaries. Statically linked binaries, for example valgrind, are not supported.
setuid binaries are also not supported ('LD_PRELOAD' disabled for security
reasons).
-
It was inspired by stderred [2]. Similar solutions (using 'LD_PRELOAD')
include:
Most other existing solutions use a second process which colors its input and
pipe stderr to it. However this creates different runtime behaviour resulting
in a different ordering of the output. Partial lines (no newline) also often
-cause problems.
+cause problems. coloredstderr handles these cases correctly (but has other
+possible issues, see below).
+
+coloredstderr is licensed under GPL 3 (or later).
DEPENDENCIES
INSTALLATION
------------
+If you're using the Git version, run `autoreconf -fsi` first to generate
+`configure`.
+
./configure && make && make check
Then either install the library with `make install` or just copy it from
COLORED_STDERR_FDS=2,
export LD_PRELOAD COLORED_STDERR_FDS
+To use coloredstderr with multi-lib (multiple architectures on the same
+system, e.g. i386 and amd64), your system must support the '$LIB' variable in
+'LD_PRELOAD'. Then you can build coloredstderr for all architectures and use
+'$LIB' in 'LD_PRELOAD'. The following should work for Debian-based systems
+with this directory structure:
+
+ dir
+ `-- lib
+ |-- i386-linux-gnu
+ | `-- libcoloredstderr.so
+ `-- x86_64-linux-gnu
+ `-- libcoloredstderr.so
+
+Now set 'LD_PRELOAD'. `lib/` is included in '$LIB'!
+
+ LD_PRELOAD='/absolute/path/to/dir/$LIB/libcoloredstderr.so'
+
+The single quotes are important. '$LIB' is not evaluated by the shell, but by
+the loader (`man ld.so`). Now both i386 and amd64 binaries automatically use
+coloredstderr.
+
The following additional environment variables are available:
are colored.
- 'COLORED_STDERR_IGNORED_BINARIES'
Comma separated list of binary names/paths which should not be tracked
- (including their children). Useful for `reset` which writes to the terminal
+ (including their children). Useful for `reset` which writes to the terminal,
but fails to work if the output is colored. See below for an example.
+ Requires `/proc/self/exe`.
All environment variables starting with 'COLORED_STDERR_PRIVATE_*' are
internal variables used by the implementation and should not be set manually.
COLORED_STDERR_POST="${esc}[0m" # default
export COLORED_STDERR_PRE COLORED_STDERR_POST
-Fix `reset`; its writes to the terminal must be unaltered. `reset` is
+Fix `reset`; its writes to the terminal must be unaltered. `reset` is a
symbolic-link to `tset` on some systems, adapt as necessary:
COLORED_STDERR_IGNORED_BINARIES=/usr/bin/tset
- `{fputc,putc,putchar}_unlocked()` are not hooked with glibc when writing to
stdout (which might be redirected to stderr). Can't be fixed as the compiler
inlines the code into the program without calling any function.
-- Test `test_stdio.sh` fails on FreeBSD because it does handle the above
+- Test `test_stdio.sh` fails on FreeBSD, because FreeBSD does handle the above
correctly (no inlining), but the test is designed for GNU/Linux.
-- 'COLORED_STDERR_IGNORED_BINARIES' requires the `/proc` file system.
- Suggestions welcome.
+- 'COLORED_STDERR_IGNORED_BINARIES' requires `/proc/self/exe`. Suggestions
+ welcome.
+- Output of `strace` is not always colored correctly as the output from
+ `coloredstderr` is traced and displayed as well. Suggestions welcome.
BUGS
coloredstderr is licensed under GPL version 3 or later.
-Copyright (C) 2013 Simon Ruderich
+Copyright (C) 2013-2014 Simon Ruderich
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
ruderich.org/simon / coloredstderr / coloredstderr.git / blobdiff