The LD_LIBRARY_PATH environment variable tells the dynamic linker where to look for shared libraries (.so files) when executing programs. This is particularly useful when:

• Testing locally compiled libraries
• Using third-party SDKs with custom library paths
• Running applications with non-standard library dependencies

For a temporary solution (valid only for current shell session):

export LD_LIBRARY_PATH=/path/to/sdk/lib:$LD_LIBRARY_PATH

For a permanent solution (applies to all future sessions), choose one of these methods:

Edit your user's bash configuration file:

nano ~/.bashrc

Add this line at the end:

export LD_LIBRARY_PATH=/path/to/sdk/lib:$LD_LIBRARY_PATH

Then apply changes:

source ~/.bashrc

For system-wide changes (requires sudo privileges):

sudo nano /etc/environment

Add your path like this (multiple paths separated by colons):

LD_LIBRARY_PATH="/path/to/sdk/lib:/another/path"

Check if your path is correctly set:

echo $LD_LIBRARY_PATH

Test library loading with:

ldd /path/to/your/executable | grep 'not found'

• Library Precedence: Libraries in LD_LIBRARY_PATH take precedence over system libraries - use with caution
• Security: Avoid using this in production environments where possible
• 64-bit vs 32-bit: On multiarch systems, you may need to set both LD_LIBRARY_PATH and LIBRARY_PATH

Instead of modifying LD_LIBRARY_PATH, consider:

1. Adding library path to /etc/ld.so.conf:

sudo sh -c 'echo "/path/to/sdk/lib" >> /etc/ld.so.conf'
sudo ldconfig

2. Using rpath during compilation:

gcc -Wl,-rpath=/path/to/sdk/lib -o myprogram myprogram.c

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The LD_LIBRARY_PATH environment variable tells the dynamic linker where to look for shared libraries when executing programs. This is particularly useful when:

• Working with custom-built libraries
• Using third-party SDKs with non-standard library locations
• Testing different library versions

Temporary solution (for current session):

export LD_LIBRARY_PATH=/path/to/sdk/lib:$LD_LIBRARY_PATH

Permanent solution (for all sessions):

Add this line to your ~/.bashrc or ~/.profile:

export LD_LIBRARY_PATH="/path/to/sdk/lib:$LD_LIBRARY_PATH"

Then run:

source ~/.bashrc

When dealing with multiple library locations:

export LD_LIBRARY_PATH="/path/to/lib1:/path/to/lib2:$LD_LIBRARY_PATH"

Check if the path is set correctly:

echo $LD_LIBRARY_PATH

Test library loading:

ldd /path/to/your/executable | grep 'not found'

For system-wide configuration (requires root privileges):

sudo sh -c 'echo "/path/to/sdk/lib" > /etc/ld.so.conf.d/custom_libs.conf'
sudo ldconfig

• Avoid adding . (current directory) to LD_LIBRARY_PATH due to security risks
• Remember that changes require terminal restart or sourcing the config file
• Prefer absolute paths over relative paths

For compiled binaries, you can hardcode library paths:

gcc -Wl,-rpath,/path/to/sdk/lib -o program program.c