[linux] How to print the ld(linker) search path



Answers

On Linux, you can use ldconfig, which maintains the ld.so configuration and cache, to print out the directories search by ld.so with

ldconfig -v 2>/dev/null | grep -v ^$'\t'

ldconfig -v prints out the directories search by the linker (without a leading tab) and the shared libraries found in those directories (with a leading tab); the grep gets the directories. On my machine, this line prints out

/usr/lib64/atlas:
/usr/lib/llvm:
/usr/lib64/llvm:
/usr/lib64/mysql:
/usr/lib64/nvidia:
/usr/lib64/tracker-0.12:
/usr/lib/wine:
/usr/lib64/wine:
/usr/lib64/xulrunner-2:
/lib:
/lib64:
/usr/lib:
/usr/lib64:
/usr/lib64/nvidia/tls: (hwcap: 0x8000000000000000)
/lib/i686: (hwcap: 0x0008000000000000)
/lib64/tls: (hwcap: 0x8000000000000000)
/usr/lib/sse2: (hwcap: 0x0000000004000000)
/usr/lib64/tls: (hwcap: 0x8000000000000000)
/usr/lib64/sse2: (hwcap: 0x0000000004000000)

The first paths, without hwcap in the line, are either built-in or read from /etc/ld.so.conf. The linker can then search additional directories under the basic library search path, with names like sse2 corresponding to additional CPU capabilities. These paths, with hwcap in the line, can contain additional libraries tailored for these CPU capabilities.

One final note: using -p instead of -v above searches the ld.so cache instead.

Question

What is the way to print the search paths that in looked by ld in the order it searches.




The most compatible command I've found for gcc and clang on Linux (thanks to armando.sano):

$ gcc -m64 -Xlinker --verbose  2>/dev/null | grep SEARCH | sed 's/SEARCH_DIR("=\?\([^"]\+\)"); */\1\n/g'  | grep -vE '^$'

if you give -m32, it will output the correct library directories.

Examples on my machine:

for g++ -m64:

/usr/x86_64-linux-gnu/lib64
/usr/i686-linux-gnu/lib64
/usr/local/lib/x86_64-linux-gnu
/usr/local/lib64
/lib/x86_64-linux-gnu
/lib64
/usr/lib/x86_64-linux-gnu
/usr/lib64
/usr/local/lib
/lib
/usr/lib

for g++ -m32:

/usr/i686-linux-gnu/lib32
/usr/local/lib32
/lib32
/usr/lib32
/usr/local/lib/i386-linux-gnu
/usr/local/lib
/lib/i386-linux-gnu
/lib
/usr/lib/i386-linux-gnu
/usr/lib



Mac version: $ ld -v 2, don't know how to get detailed paths. output

Library search paths:
    /usr/lib
    /usr/local/lib
Framework search paths:
    /Library/Frameworks/
    /System/Library/Frameworks/



Related