which and whereis for commands in Linux CLI - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the which command do in Linux?

The which command shows the full path of the executable file that would run if you typed a command. It helps find where a command is located in your system's PATH.

intermediate

What is the difference between which and whereis commands?

which shows the path of the executable that runs for a command. whereis shows locations of the binary, source, and manual files related to the command.

beginner

How do you use which to find the path of the python3 command?

Type which python3 in the terminal. It will print the full path of the python3 executable if it is found in your PATH.

intermediate

What kind of files does whereis locate for a command?

whereis locates the binary executable, source code files, and manual (man) pages related to a command.

beginner

If which returns no output for a command, what does that mean?

It means the command is not found in any directory listed in your PATH environment variable, so it likely isn't installed or accessible from your current shell.

What does the which command show?

A All files related to a command including source and man pages

B The last time the command was used

C The size of the command's executable

D The full path of the executable that runs for a command

which shows the path of the executable that runs when you type a command.

Which command shows the binary, source, and manual files for a command?

A which

B find

C whereis

D locate

whereis locates binary, source, and manual files related to a command.

If you want to find where the ls command executable is, which command do you use?

A which ls

B find ls

C whereis ls

D locate ls

which ls shows the path of the ls executable.

What does it mean if which returns no output for a command?

A The command is broken

B The command is not in your PATH

C The command is hidden

D The command is running

No output means the command is not found in directories listed in your PATH.

Which command would you use to find the manual page location for grep?

A whereis grep

B which grep

C man grep

D locate grep

whereis grep shows locations of binary, source, and manual files.

Explain how which and whereis commands help you find information about commands in Linux.

Think about what each command tells you about a program.

Describe a situation where you would use which and another where you would use whereis.

Consider simple command use vs deeper info needs.