Sfdwhf

I am a noobie. I tried searching the duplicates for answers, but none worked. I accidentally altered my $PATH variable in my terminal when trying to install ghc. Every time I open a terminal window I get:

bash: export: `/.cabal/bin:/opt/ghc/7.6.3/bin:': not a valid identifier

bash: warning: here-document at line 120 delimited by end-of-file (wanted 

EOF')

Command 'cat' is available in '/bin/cat'

The command could not be located because '/bin' is not included in the 

PATH environment variable.

cat: command not found

When I type:

echo $PATH

it gives me the following:

/.cabal/bin:/opt/cabal/1.16/bin:/opt/ghc/7.6.3/bin:

I can fix it by typing:

source /etc/environment

But that's only for the current terminal session. If I close the window and open a new one, it goes back to the wrong $PATH.

How can I permanently reset my $PATH back to the default?

Building on the comments made by steeldriver try the following two simple steps:

1. Backup existing config:

mv -v ~/.bashrc ~/.bashrc_bak && mv -v ~/.profile  ~/.profile_bak

2. Create new, safe copies:

cp -v /etc/skel/{.bashrc,.profile} $HOME

Note: This can all be accomplished with a one-liner, demonstrated on my own system:

andrew@athens:~$ cp -v -S _bak /etc/skel/{.bashrc,.profile} $HOME

'/etc/skel/.bashrc' -> '/home/andrew/.bashrc' (backup: '/home/andrew/.bashrc_bak')

'/etc/skel/.profile' -> '/home/andrew/.profile' (backup: '/home/andrew/.profile_bak')

andrew@athens:~$ 

And finally add any customisations made by yourself previously from the 2 backup files, by 'customisations' I mean such things as:

1. Alterations to the default $PATH made in these files, I note in your case you have installed to /opt which is not in the default $PATH
   


2. Alterations to the default Terminal prompt


3. Additions to the default aliases

And any other changes that have been made to the safe defaults of both files...

There are a lot of options.
You can give a look here.

Keep in mind that in the link I sent you they mainly suggest how to set the path in the current session.

However if you change the path to the suggested values in ~/.profile or ~/.bashrc (depending which one you modified) you should be fine.

I hope this is helpful:

rick@dell:~$ echo "$PATH"

/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin

I haven't changed my path (that I can recall) I notice "games" is in there but I don't play games so I assume it's a default. You might want to use this as a starting path to get you started on the right path, so to speak.

I'm using Ubuntu 16.04.

To add paths this link might be helpful: unix-linux-adding-path.

Follow these step to recover the PATH environment variable :

• Delete the culprit file from /etc/profile.d/ (if any)


• Delete the culprit line from /etc/profile or ~/.bashrc (if any)


• Execute source /etc/environment to start reseting the path environment variable


• Execute source /etc/profile followed by source /etc/profile.d/*
  


• At last source ~/.bashrc