4 coloredstderr is a small library which uses 'LD_PRELOAD' to color stderr.
7 Like all solutions using 'LD_PRELOAD' it only works with dynamically linked
8 binaries. Statically linked binaries, for example valgrind, are not supported.
11 It was inspired by stderred [2]. Similar solutions (using 'LD_PRELOAD')
14 - stderred [1], but doesn't `follow' dups (I somehow missed it when looking
15 for existing implementations)
16 - stderred [2], but only hooks `write()`
18 [1]: https://github.com/sickill/stderred
19 [2]: https://github.com/trapd00r/stderred
21 Most other existing solutions use a second process which colors its input and
22 pipe stderr to it. However this creates different runtime behaviour resulting
23 in a different ordering of the output. Partial lines (no newline) also often
30 - C99 compiler (variable length arrays)
31 - dynamic linker/loader which supports 'LD_PRELOAD' (e.g. GNU/Linux's ld.so)
37 Set 'LD_PRELOAD' to include the _absolute_ path to `libcoloredstderr.so`:
39 LD_PRELOAD=/absolute/path/to/libcoloredstderr.so
41 The 'COLORED_STDERR_FDS' environment variable must be set to the file
42 descriptors which should be colored (comma separated list). Normally this is
47 The trailing comma is important!
50 A default setup could look like this:
52 LD_PRELOAD="$HOME/bin/libcoloredstderr.so"
54 export LD_PRELOAD COLORED_STDERR_FDS
57 The following additional environment variables are available:
59 - 'COLORED_STDERR_PRE'
60 String to write before each write to stderr, defaults to "\033[91m" (bright
62 - 'COLORED_STDERR_POST'
63 String to write after each write to stderr, defaults to "\033[0m" (reset
65 - 'COLORED_STDERR_FORCE_WRITE'
66 If set to an non-empty value add pre/post strings even when not writing to a
67 terminal, e.g. when writing to a file. By default, only writes to a terminal
74 To enable debug mode, configure coloredstderr with '--enable-debug'.
76 *Important:* Debug mode enables `assert()`s in the code which might abort the
77 process if an error condition is detected!
79 Debug mode is slower than normal mode. To log only warnings without the
80 overhead of debug mode use '--enable-warnings'. `assert()`s are not enabled
81 with '--enable-warnings', so it's safe to use.
83 Debug messages are written to the file `colored_stderr_debug_log.txt` in the
84 current working directory _if_ it exists. If it exists debug messages are
85 appended. Be careful, this file might grow very quickly.
87 *Important:* Warnings are written to `$HOME/colored_stderr_warning_log.txt`
88 even if it _does not_ exist (only if debug or warning mode is enabled)! If it
89 doesn't exist it's created. An existing file isn't overwritten, but the
90 warnings are appended at the end.
96 If you find any bugs not mentioned in this document please report them to
97 <simon@ruderich.org> with coloredstderr in the subject.
103 Written by Simon Ruderich <simon@ruderich.org>.
109 coloredstderr is licensed under GPL version 3 or later.
111 Copyright (C) 2013 Simon Ruderich
113 This program is free software: you can redistribute it and/or modify
114 it under the terms of the GNU General Public License as published by
115 the Free Software Foundation, either version 3 of the License, or
116 (at your option) any later version.
118 This program is distributed in the hope that it will be useful,
119 but WITHOUT ANY WARRANTY; without even the implied warranty of
120 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
121 GNU General Public License for more details.
123 You should have received a copy of the GNU General Public License
124 along with this program. If not, see <http://www.gnu.org/licenses/>.