Linux Binaries and Libraries

To find our which libraries a linux binary uses, run the ldd command against it.

      ldd /usr/bin/top =>  (0x00007fffc6eaf000) => /lib64/ (0x0000003a58000000) => /lib64/ (0x0000003a5b000000) => /lib64/ (0x0000003a57c00000) => /lib64/ (0x0000003a59c00000) => /lib64/ (0x0000003a57800000)
      /lib64/ (0x0000003a57400000)

If you get a “file not found” message, the binary can't find the libabry it requires. Assuming it has been installed, the path can be added to the LD_LIBRARY_PATH variable.

To find out which libraries are known, use ldconfig -p to list them

      ldconfig -p | more
      730 libs found in cache `/etc/' (libc6,x86-64) => /lib64/ (libc6) => /lib/ (libc6,x86-64) => /usr/lib64/xulrunner/ (libc6,x86-64) => /lib64/ (libc6,x86-64) => /usr/lib64/ (libc6,x86-64) => /usr/lib64/xulrunner/ (libc6,x86-64) => /usr/lib64/ (libc6,x86-64) => /usr/lib64/ (libc6,x86-64) => /usr/lib64/ (libc6,x86-64) => /usr/lib64/ (libc6,x86-64) => /usr/lib64/ (libc6,x86-64) => /usr/lib64/ (libc6,x86-64) => /usr/lib64/ (libc6,x86-64) => /usr/lib64/ (libc6,x86-64) => /usr/lib64/

As the command indicates, these are the libraries that have been cached. Additional (non default) locations can be added by configuring file /etc/ or adding configuration files to /etc/ . After this ldconfig (with no arguments) must be run to refresh the cache.

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