bash Cookbook

Setting a POSIX $PATH

Problem

You are on a machine that provides older or proprietary tools (e.g., Solaris) and you need to set your PATH so that you get POSIX-compliant tools.

Solution

Use the getconf utility:

PATH=$(PATH=/bin:/usr/bin getconf PATH)

Here are some default and POSIX paths on several systems:

# Red Hat Enterprise Linux (RHEL) 4.3
$ echo $PATH
/usr/kerberos/bin:/usr/local/bin:/bin:/usr/bin:/usr/X11R6/bin:/home/$USER/bin

$ getconf PATH
/bin:/usr/bin


# Debian Sarge
$ echo $PATH
/usr/local/bin:/usr/bin:/bin:/usr/bin/X11:/usr/games

$ getconf PATH
/bin:/usr/bin


# Solaris 10
$ echo $PATH
/usr/bin:

$ getconf PATH
/usr/xpg4/bin:/usr/ccs/bin:/usr/bin:/opt/SUNWspro/bin

# OpenBSD 3.7
$ echo $PATH
/home/$USER/bin:/bin:/sbin:/usr/bin:/usr/sbin:/usr/X11R6/bin:/usr/local/bin:/usr/
local/sbin:/usr/games

$ getconf PATH
/usr/bin:/bin:/usr/sbin:/sbin:/usr/X11R6/bin:/usr/local/bin

Discussion

getconf reports various system configuration variables, so you can use it to set a default path. However, unless getconf itself is a built-in, you will need a minimal path to find it, hence the PATH=/bin:/usr/bin part of the solution.

In theory, the variable you use should be CS_PATH. In practice, PATH worked every-where we tested while CS_PATH failed on the BSDs.

See Also

• http://www.unixreview.com/documents/s=7781/uni1042138723500/

• Finding a File Using a List of Possible Locations

• Setting a Secure $PATH

• Finding World-Writable Directories in Your $PATH

• Adding the Current Directory to the $PATH

• Change Your $PATH Permanently ...