etc/apt/sources.list not found [duplicate]

Question

I was trying to edit source.list for apt-get install update and generated new source code from repogen.simplylinux.ch and I don't know what happened during editing but now when I type version then it says:

WARNING:root:could not open file '/etc/apt/sources.list'
   version: command not found

and when I do apt-get install mtools then it says:

root@spider-laptop:~# apt-get install mtools
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package mtools is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source  
E: Package 'mtools' has no installation candidate

Answer 1

It sounds like your sources.list file is missing, based on your topic description. Check if the file is indeed missing...

file /etc/apt/sources.list

If it is missing, I've attached a copy of the original sources.list file at the end of this answer. (By the way, I noticed you are logged in as root. It's probably better to login as an admin user and elevate your privileges as/when needed).

In a terminal type

gksudo gedit /etc/apt/sources.list

Cut and paste the contents of sources list shown at the end of this answer. Close gedit, and enter the following in your terminal

sudo apt-get update

Regarding other repositories you may have added, open a new question as suggested.

Standard sources.list file (14.04)

#deb cdrom:[Ubuntu 14.04 LTS _Trusty Tahr_ - Release amd64 (20140417)]/ trusty main restricted

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://us.archive.ubuntu.com/ubuntu/ trusty main restricted
deb-src http://us.archive.ubuntu.com/ubuntu/ trusty main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://us.archive.ubuntu.com/ubuntu/ trusty-updates main restricted
deb-src http://us.archive.ubuntu.com/ubuntu/ trusty-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://us.archive.ubuntu.com/ubuntu/ trusty universe
deb-src http://us.archive.ubuntu.com/ubuntu/ trusty universe
deb http://us.archive.ubuntu.com/ubuntu/ trusty-updates universe
deb-src http://us.archive.ubuntu.com/ubuntu/ trusty-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu 
## team, and may not be under a free licence. Please satisfy yourself as to 
## your rights to use the software. Also, please note that software in 
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://us.archive.ubuntu.com/ubuntu/ trusty multiverse
deb-src http://us.archive.ubuntu.com/ubuntu/ trusty multiverse
deb http://us.archive.ubuntu.com/ubuntu/ trusty-updates multiverse
deb-src http://us.archive.ubuntu.com/ubuntu/ trusty-updates multiverse

## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://us.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse
deb-src http://us.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse

deb http://security.ubuntu.com/ubuntu trusty-security main restricted
deb-src http://security.ubuntu.com/ubuntu trusty-security main restricted
deb http://security.ubuntu.com/ubuntu trusty-security universe
deb-src http://security.ubuntu.com/ubuntu trusty-security universe
deb http://security.ubuntu.com/ubuntu trusty-security multiverse
deb-src http://security.ubuntu.com/ubuntu trusty-security multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
# deb http://archive.canonical.com/ubuntu trusty partner
# deb-src http://archive.canonical.com/ubuntu trusty partner

## This software is not part of Ubuntu, but is offered by third-party
## developers who want to ship their latest software.
deb http://extras.ubuntu.com/ubuntu trusty main
deb-src http://extras.ubuntu.com/ubuntu trusty main

Generate a sources.list file instead

You can generate a list interactively via this URL: https://repogen.simplylinux.ch/

Answer 2

sudo -H leafpad /etc/apt/sources.list

works for me