Ldd mail

A Linux command!

ldd is a command that displays the dynamic linker dependencies of a given executable or library. It shows which shared libraries are required by the program to run.

When you run ldd followed by the name of an executable or library, it will output a list of shared libraries that the program depends on, along with the version numbers of those libraries.

For example, if you run ldd mail (assuming there's an executable or library named mail), you might see output like this:

linux-vdso.so.1 =>  (0x00007fff5f7f6000)
libssl.so.1.1 => /usr/lib/x86_64-linux-gnu/libssl.so.1.1 (0x00007f5a5f5f4000)
libcrypto.so.1.1 => /usr/lib/x86_64-linux-gnu/libcrypto.so.1.1 (0x00007f5a5f3f4000)
libz.so.1 => /usr/lib/x86_64-linux-gnu/libz.so.1 (0x00007f5a5f1f4000)
libc.so.6 => /usr/lib/x86_64-linux-gnu/libc.so.6 (0x00007f5a5efc4000)
/lib64/ld-linux-x86-64.so.2 => /usr/lib/x86_64-linux-gnu/lib64/ld-linux-x86-64.so.2 (0x00007f5a5f7f6000)

This output shows that the mail program depends on several shared libraries, including libssl.so.1.1, libcrypto.so.1.1, libz.so.1, and libc.so.6. The version numbers of these libraries are also displayed.

ldd is a useful tool for troubleshooting issues with shared libraries, as it can help you identify which libraries are required by a program and whether they are present on the system.