Understanding File Permissions for Executable Binary Files

C

The permissions -rwSr-xr-x on a binary file mean the following:

• The first character "-" indicates that this is a regular file.
• The next three characters "rw-" indicate that the owner has read and write permissions but not execute permission.
• The fourth character "S" indicates that the SetUID bit is set. This means that the command will be executed with the effective rights of the owner, not the user who is executing the command. This is often used for programs that need special privileges, such as accessing system resources or performing administrative tasks.
• The next three characters "r-x" indicate that the group has read and execute permissions, but not write permission.
• The final three characters "r-x" indicate that other users have read and execute permissions, but not write permission.

Therefore, the correct answer is A: The command is SetUID and it will be executed with the effective rights of the owner. The SetUID bit overrides the execute permission for the owner, so the owner does not need execute permission to run the command. The group and other users will have their regular permissions applied when running the command.