add a folder to PATH, but not if it is already in PATH

jmcvetta (Jason McVetta) — Wed, 28 Nov 2007 18:38:16 GMT

Often times one uses a single .profile or .bashrc across several hosts. These hosts may be differently configured, with varying directory locations, and different initial PATH values from /etc/profile. In situations like this, setting PATH the traditional way -- "PATH=$PATH:/path/to/some/stuff" -- can result in a cumbersomely long PATH that includes inaccessible or duplicate folders.

The snippet below nicely handles this problem. It has been tested on Solaris and Linux.



AddPath ()

# Add argument to $PATH if:

# - it is not already present

# - it is a directory

# - we have execute permission on it

#

# This snippet is public domain; you may use it freely.  Death to copyright, patents, 

# and all other forms of intellectual monopoly.  

#

{

  _folder=$1

  echo " $PATH " | sed 's/:/ /g' | grep " $_folder " > /dev/null

  [ $? -ne 0 ] && [ -d $_folder ] && [ -x $_folder ] && PATH=$PATH:$_folder

  export PATH

}



# Add some common paths:

AddPath /usr/bin

AddPath /usr/local/bin

AddPath /opt/somepackage/bin

DZone Snippets: path code

add a folder to PATH, but not if it is already in PATH