Where is $PATH located?

Question

ubuntu

Hello, I'm trying to use an already written bioinformatics program ( www.di-tector.cyame.eu ) and after I run it with all parameters and input arguments I get the following:

FileNotFoundError: [Errno 2] No such file or directory: 'samtools': 'samtools'

At the same time, at the very beginning of the program, the following is written:

=================================
Program: DI-tector
Version: 0.6 - Last modified 25/05/2018
=================================
Requirement: (must be in your $PATH)
-bwa
-samtools

Optional: (must be in your $PATH)
-bedtools

What does must be in your $PATH mean ?

Where do you need to install these same samtools and bwa?

Thanks a lot!

Answer 1

You need to add paths to bwa and samtools to the $PATH variable.
Approximately like this (execute before starting the program):

export PATH=$PATH:/путь_до_директории_с_выше_указанными_файлами

Answer 2

Well, it's clearly written. Apparently there are bwa and samtools executable files, the directory where they are located should be in the PATH variable,
look where they are installed and add this path to PATH.