What is fetch command on ubuntu?
fetch is not a standard command on Ubuntu.
$ cat /etc/os-release
NAME="Ubuntu"
VERSION="14.04.5 LTS, Trusty Tahr"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 14.04.5 LTS"
VERSION_ID="14.04"
HOME_URL="http://www.ubuntu.com/"
SUPPORT_URL="http://help.ubuntu.com/"
BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"
$ type time
time is a shell keyword
$ type ls
ls is aliased to `ls --color=auto'
$ type git
git is /usr/bin/git
$ type fetch
-bash: type: fetch: not found
It is likely that the instructions you are following have omitted to mention some non-standard prerequisites that must be installed first.
I don't get the meaning of the message -bash: fetch: command not found
The command shell, bash, is telling you that it cannot find a command named "fetch" or it is reporting an error returned by a fetch command it did find.
This general sort of error message can occur when the command does not exist or when it is the name of a program that is not in the current $PATH.