Linux system Add, modify, delete path environment variables

I. Adding environment variables

(Use Export,c shell with setenv in Bash shell)

1. Modify directly at the terminal:

Export path= $PATH: Software_installation_path/bin

Modification is only valid for this process

2. Modify the User level

In home/user/.profile, add:

Export path= $PATH: Software_installation_path/bin

Save the file, reboot (some system execution./.profile, no reboot required; some systems must be restarted)

3. Modify the system level

Cd/etc/profile

VI Profile

Export path= $PATH: Software_installation_path/bin

Save the file, reboot (some system execution./profile, no reboot required; some systems must be restarted)

After restarting, you can see the PATH environment variable to see if it changes:

Echo $PATH

Two. Renaming of environment variables

Echo ${path/old_name/new_name} #变更一个目录名old_name

Echo ${path//old_name/new_name} #变更所有目录名old_name

Three environment variable Deletion

echo ${path#/deletion_name:}

Linux system Add, modify, delete path environment variables