Apple - Terminal returns not found for most commands Mac OSX

$PATH should contain these folders: /usr/bin:/usr/sbin:/bin:/sbin.

Try editing ~/.bash_profile, ~/.profile, or ~/.bash_login (with for example /usr/bin/open ~/.bash_profile -a TextEdit) and commenting out any lines that modify the path.

If that works, you can add a line like export PATH=/opt/local/bin:/opt/local/sbin:$PATH to ~/.bash_profile.

Similar problem was happening to me, so what I did was:

1) typing export PATH="/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin" into the terminal in order to make it temporarily working

2) Editing bash_profile by typing /usr/bin/open ~/.bash_profile -a TextEdit

3) When I opened my bash_profile file I realised the last line export looked really messy with some strange symbols, so I changed it entirely to export PATH=/opt/local/bin:/opt/local/sbin:$PATH

I'm an absolutely beginner at this but I managed to get those steps by reading pieces of solutions from different questions on SE, so hope it could help someone else.

It sounds like you overwrote your path rather then just adding to it.

Make sure when you set your PATH you include "${PATH}" to include your existing path, as well.

By default the $PATH is set in a couple of files. Technically you should add to your $PATH in the .bash_profile file in your home directory.

One suggestion if to check if a certain folder exists before you add them to your PATH.

For example I have:

if [ -d /usr/local/bin ] ; then
    PATH=/usr/local/bin:"${PATH}"
fi

if [ -d /usr/local/mysql/bin ] ; then
    PATH=/usr/local/mysql/bin:"${PATH}"
fi

if [ -d /opt/local/bin ] ; then
    PATH=/opt/local/bin:"${PATH}"
fi

if [ -d /opt/local/sbin ] ; then
    PATH=/opt/local/sbin:"${PATH}"
fi

if [ -d ~/bin ] ; then
    PATH=~/bin:"${PATH}"
fi

(The -d directory command checks to see if the directory exists)