Linux
modify the profile file to make a mistake, the recovery method
When I changed the profile, the problem was fixed. The commands other than cd could not be used, and even vi could not be used. I checked the Internet and used
export PATH=/usr/bin:/usr/sbin:/bin:/sbin:/usr/X11R6/bin
Then you can use the command, change the profile back with vi, and return to normal.
Shell commands are basically defined in /usr/bin, /usr/sbin, /bin, /sbin, and /usr/X11R6/bin.
Therefore, as long as these commands are taken out again, they can be used, which can be regarded as a remedy.