For some reason, many command I try to execute I get
command not found
touch, mkdir, sudo, ln -s all the same result
ilyas-mac-pro:~ ilya$ mkdir bla -bash: mkdir: command not found
You changed your
$PATH (more about it). Try to enter the full path of commands, e.g.
/usr/bin/mkdir, not sure right now).
echo $PATH to see the current path variable value.
export PATH=/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/X11/bin for a sane value.
Check your shell init files, e.g.
.bash_profile for lines like the
export PATH=... above and remove them.