Discussion is here[1].
Apparently there is a hidden feature in ld.so, it support variable
placeholders within environment.
This is great for supporting mixed multilib environment.
Example:
export LD_LIBRARY_PATH="${LD_LIBRARY_PATH}:/opt/my/\${LIB}"
I believe this worth a documentation, as almost nobody knows this.
---
ENVIRONMENT
+ ld.so understands the strings $ORIGIN, $LIB and $PLATFORM (or equiva‐
+ lently ${var}) in some of the environment variables, such as
+ LD_LIBRARY_PATH and LD_PRELOAD:
+
+ ORIGIN is expanded to the location of the binary which is cur‐
+ rently loaded.
+
+ LIB is expanded to lib, lib64 or any other multilib configura‐
+ tion based on the ld configuration. Use when mixed environment
+ (32bit and 64bit) searches for same libraries names.
+
+ PLATFORM is expanded to the running platform.
There are four important environment variables.
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Any test will do! as long as this feature gets documented.
Signed-off-by: Alon Bar-Lev <alon.barlev@xxxxxxxxx>
[1] http://sourceware.org/ml/libc-alpha/2011-08/msg00089.html
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