View and add PATH environment variables in Linux

View and add PATH environment variables in Linux

$ PATH: determines which directories The shell will look for commands or programs. The PATH value is a series of directories. When you run a program, Linux searches for compilation links under these directories.

Edit your PATH declaration in the following format:

PATH = $ PATH: <PATH 1 >:< PATH 2 >:< PATH 3 >:------: <path n>

You can add the specified path by yourself, separated by a colon in the middle. After the environment variable is changed, it will take effect the next time you log in. If you want to take effect immediately, you can execute the following statement: $ source. bash_profile

Note that it is best not to put the current PATH "./" in the PATH, which may be subject to unexpected attacks. After that, you can view the current search PATH through $ echo $ PATH. In this way, you can avoid frequent startup of programs outside the shell search path.

Use the export command to view the PATH value

[Root @ localhost u-boot-sh4] # export
Declare-x CVS_RSH = "ssh"
Declare-x DISPLAY = ": 0.0"
Declare-x G_BROKEN_FILENAMES = "1"
Declare-x HISTSIZE = "1000"
Declare-x HOME = "/root"
Declare-x HOSTNAME = "localhost"
Declare-x INPUTRC = "/etc/inputrc"
Declare-x LANG = "zh_CN.UTF-8"
Declare-x LESSOPEN = "|/usr/bin/lesspipe. sh % s"
Declare-x LOGNAME = "root"
Declare-x LS_COLORS = "no = 00: fi = 00: di = 00; 34: ln = 00; 36: pi = 40; 33: so = 00; 35: bd = 40; 33; 01: cd = 40; 33; 01: or = 01; 05; 37; 41: mi = 01; 05; 37; 41: ex = 00; 32 :*. cmd = 00; 32 :*. exe = 00; 32 :*. com = 00; 32 :*. btm = 00; 32 :*. bat = 00; 32 :*. sh = 00; 32 :*. csh = 00; 32 :*. tar = 00; 31 :*. tgz = 00; 31 :*. arj = 00; 31 :*. taz = 00; 31 :*. lzh = 00; 31 :*. zip = 00; 31 :*. z = 00; 31 :*. Z = 00; 31 :*. gz = 00; 31 :*. bz2 = 00; 31 :*. bz = 00; 31 :*. tz = 00; 31 :*. rpm = 00; 31 :*. cpio = 00; 31 :*. jpg = 00; 35 :*. gif = 00; 35 :*. bmp = 00; 35 :*. xbm = 00; 35 :*. xpm = 00; 35 :*. png = 00; 35 :*. tif = 00; 35 :"
Declare-x MAIL = "/var/spool/mail/root"
Declare-x OLDPWD = "/root"
Declare-xPATH = "/usr/kerberos/sbin:/usr/kerberos/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin: /usr/sbin:/usr/bin:/root/bin"
Declare-x PWD = "/opt/STM/STLinux-2.3/devkit/sources/u-boot/u-boot-sh4"
Declare-x SHELL = "/bin/bash"
Declare-x SHLVL = "1"
Declare-x SSH_ASKPASS = "/usr/libexec/openssh/gnome-ssh-askpass"
Declare-x TERM = "xterm"
Declare-x USER = "root"
Declare-x XAUTHORITY = "/root/. xauthkSzH7b"
 
View the PATH environment variables separately. Available:
 
[Root @ localhost u-boot-sh4] # echo $ PATH
/Usr/kerberos/sbin:/usr/kerberos/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin: /usr/bin:/root/bin
 
Add the PATH environment variable. Available:
 
[Root @ localhost u-boot-sh4] # export PATH =/opt/STM/STLinux-2.3/devkit/sh4/bin: $ PATH
 
View again:
 
[Root @ localhost u-boot-sh4] # echo $ PATH
/Opt/STM/STLinux-2.3/devkit/sh4/bin:/usr/kerberos/sbin:/usr/kerberos/bin:/usr/local/sbin: /usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin
 
The PATH is successfully added.
 
The PATH of the above method disappears after the terminal is closed. Therefore, we recommend that you modify the PATH by editing/etc/profile, or change the. bashrc (that is, ~) in the home directory :~ /. Bashrc ).
 
Method 2:
 
# Vim/etc/profile
 
At the end of the document, add:
 
Export PATH = "/opt/STM/STLinux-2.3/devkit/sh4/bin: $ PATH"
 
Save, exit, and run:
 
# Source/etc/profile
 
If no error is reported, the operation is successful.