Introduction to the x86_64-linux-gnu-nm Command

The x86_64-linux-gnu-nm command is a Linux tool used to list symbols from object files. It is commonly used to examine the contents of a given object file, such as an executable or library. It can be used to list the symbols in an object file, including the symbol type, size, and address. It can also be used to list the symbols in a shared library, which can be useful for debugging and troubleshooting.

Basic Usage and Syntax

The basic syntax for x86_64-linux-gnu-nm is as follows:

nm [options] [object_file]

The command takes in an object file as its argument and then lists the symbols in that file. The options can be used to modify the output of the command, such as to list only certain types of symbols or to list the size and address of each symbol.

Examples of Common Use Cases

• List all symbols in an object file:

  nm my_object_file.o

• List all symbols of type ‘data’ in an object file:

  nm -D my_object_file.o

• List all symbols in a shared library:

  nm -D /usr/lib/libc.so.6

• List all symbols of type ‘function’ in a shared library:

  nm -D -f funct /usr/lib/libc.so.6

Advanced Options and Flags

The x86_64-linux-gnu-nm command has a number of advanced options and flags that can be used to modify the output of the command. These include:

• -a

  : List all symbols, including those that are not visible outside the object file.

• -D

  : List only data symbols.

• -f funct

  : List only function symbols.

• -l

  : List the size and address of each symbol.

• -o

  : List only symbols that are visible outside the object file.

• -s

  : List only symbols of type ‘section’.

• -t

  : List only symbols of type ‘text’.

• -u

  : List only undefined symbols.

• -v

  : List only symbols of type ‘variable’.

Examples in Real-World Scenarios

The x86_64-linux-gnu-nm command can be used in a variety of real-world scenarios. For example, it can be used to list the symbols in a shared library that is causing a problem in an application. It can also be used to list the symbols in an executable to determine which functions are being called.

Troubleshooting Tips and Potential Errors

When using the x86_64-linux-gnu-nm command, it is important to be aware of potential errors and troubleshooting tips. One common error is the “No such file or directory” error, which can occur if the object file specified does not exist. Another common error is the “Permission denied” error, which can occur if the user does not have the necessary permissions to access the object file.

It is also important to be aware of the various options and flags that can be used to modify the output of the command. For example, using the “-D” flag will list only data symbols, while using the “-f funct” flag will list only function symbols.