tests: Check return values of write() and dup2().

[coloredstderr/coloredstderr.git] / README

diff --git a/README b/README
index 34cff3029bd41bdcdf99e6bec6631c8d5990d0cd..79a40843429a4c66f346cf893be42c29f4834cb3 100644 (file)
--- a/README
+++ b/README
@@ -6,6 +6,8 @@ coloredstderr is a small library which uses 'LD_PRELOAD' to color stderr.
 
 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')
@@ -51,6 +53,11 @@ inconsistent state causing a segmentation fault when using any functions of
 the library. Just remove the file first and then copy it. `make install`
 handles the install in this way and is therefore not affected.
 
+As a simple safeguard, `make` builds and installs the `libcoloredstderr.so`
+file non-writable to prevent accidental overwrites. Even if the overwrite is
+forced with `cp -f`, the file is unlinked and recreated by `cp` because the
+file is non-writable, preventing the problem.
+
 
 USAGE
 -----
@@ -88,6 +95,10 @@ The following additional environment variables are available:
   terminal, e.g. when writing to a file. By default, only writes to a terminal
   are colored.
 
+All environment variables starting with 'COLORED_STDERR_PRIVATE_*' are
+internal variables used by the implementation and should not be set manually.
+See the source for details.
+
 
 To set custom colors as pre/post strings you can use the `$''` feature of Bash
 and Zsh: