Mastering Linux Shell Scripting - Second Edition

Command type

For example, if we type and enter ls to list files, it is reasonable to think that we were running the command. It is possible, but we often will be running an alias. Aliases exist in memory as a shortcut to commands or commands with options; these aliases are used before we even check for the file. Bash's built-in type command can come to our aid here. The type command will display the type of command for a given word entered at the command line. The types of command are listed as follows:

• Alias
• Function
• Shell built-in
• Keyword
• File

This list is also representative of the order in which they are searched. As we can see, it is not until the very end where we search for the executable file ls.

The following command demonstrates ...