Set path in Linux

PATH is an environment variable. To check the current environment variable in uppercase, set echo $ path: Export Path =/usr/local/sbin:/usr/local/bin:/sbin:/bin: /usr/sbin:/usr/bin or export Path = path:/XXX is invalid after it is logged out. Keep it valid. Modify ~ /. Bashrc or ~ /. Bash_profile or system-level/etc/profile PS: for example, in windows, software is installed in different directories under program file, while in UNIX, executable files are placed in path, the library files are stored in the Lib at the same level to facilitate command input.