Fix "Command Not Found" in Linux

What it means

Linux cannot find the program you tried to run.

Example:

command: not found

Possible Causes

• Program is not installed
• The command name is incorrect
• The program is not in your PATH

Fix 1 — Install the program

Example on Ubuntu:

sudo apt install program_name

Fix 2 — Check spelling

Linux commands are case sensitive.

Example:

python3 != Python3

Fix 3 — Check PATH

See where commands are searched:

echo $PATH

Find the command location:

which command_name

Fix 4 — Run from current directory

If running a script in the current folder:

./script.sh

Notes

• Many new users forget the "./" prefix when running local scripts.