Mac OS X: Set / Change $PATH Variable

I

need to add dev tools (such as JDK and friends) to my PATH. How do I change $PATH variable in OS X 10.8.x? Where does $PATH get set in OS X 10.8 Mountain Lion?

 

$PATH is nothing but an environment variable on Linux, OS X, Unix-like operating systems, and Microsoft Windows. You can specify a set of directories where executable programs are located using $PATH. The $PATH variable is specified as a list of directory names separated by colon (:) characters. To print the current settings, open the Terminal and then type:

echo  $PATH

OR

printf  %s\n  $PATH

Sample outputs:

Fig.01: Displaying the current $PATH settings using echo / printf on OS X

OS X: Change your PATH environment variable

You can add path to any one of the following method:

$HOME/.bash_profile file using export syntax.

/etc/paths.d directory.

Method #1: $HOME/.bash_profile file

The syntax is as follows:

export PATH=$PATH:/new/dir/location1

export PATH=$PATH:/new/dir1:/dir2:/dir/path/no3

In this example, add /usr/local/sbin/modemZapp/ directory to $PATH variable. Edit the file $HOME/.bash_profile, enter:

vi $HOME/.bash_profile

 

OR

vi ~/.bash_profile

 

Append the following export command:

export PATH=$PATH:/usr/local/sbin/modemZapp

Save and close the file. To apply changes immedialty enter:

source $HOME/.bash_profile

 

OR

. $HOME/.bash_profile

 

Finally, verify your new path settings, enter:

echo $PATH

 

Sample outputs:

/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/opt/X11/bin:/usr/local/sbin/modemZapp

Method #2: /etc/paths.d directory

Apple recommends the path_helper tool to generate the PATH variable i.e. helper for constructing PATH environment variable. From the man page:

The path_helper utility reads the contents of the files in the directories /etc/paths.d and /etc/manpaths.d and appends their contents to the PATH and MANPATH environment variables respectively.

(The MANPATH environment variable will not be modified unless it is already set in the environment.)

Files in these directories should contain one path element per line.

Prior to reading these directories, default PATH and MANPATH values are obtained from the files /etc/paths and /etc/manpaths respectively.

To list existing path, enter:

ls -l /etc/paths.d/

 

Sample outputs:

total 16

-rw-r–r–  1 root  wheel  13 Sep 28  2012 40-XQuartz

You can use the cat command to see path settings in 40-XQuartz:

cat /etc/paths.d/40-XQuartz

 

Sample outputs:

/opt/X11/bin

To set /usr/local/sbin/modemZapp to $PATH, enter:

sudo -s  echo  /usr/local/sbin/modemZapp  > /etc/paths.d/zmodemapp

OR use vi text editor as follows to create /etc/paths.d/zmodemapp file:

sudo vi /etc/paths.d/zmodemapp

 

and append the following text:

/usr/local/sbin/modemZapp

Save and close the file. You need to reboot the system. Alternatively, you can close and reopen the Terminal app to see new $PATH changes.

Conclusion

Use $HOME/.bash_profile file when you need to generate the PATH variable for a single user account.

Use /etc/paths.d/ directory via the path_helper tool to generate the PATH variable for all user accounts on the system. This method only works on OS X Leopard and higher.

See also:

Customize the bash shell environments from the Linux shell scripting wiki.

UNIX: Set Environment Variable

Man pages – bash(1), path_helper(8)