Add multiple subdirectories under the same parent directory to PATH

Question

I have installed some tools and put it under $HOME/tools/ and each tool has its own /bin directory that contains the executable program. I now have the path to each individual /bin in my $HOME/.bashrc file like this:

export PATH=$PATH:$HOME/tools/tool1/bin
export PATH=$PATH:$HOME/tools/tool2/bin
...

I'm wondering if it's OK to write the following for all the tools?

export PATH=$PATH:$HOME/tools

If it doesn't work, what is the best way to do this?

Answer 1

Adding a directory to PATH only makes the executables in this directory available as bare command names. This does not extend to subdirectories.

You can put a loop in your .profile (not .bashrc) to add multiple directories, for example:

for d in ~/tools/*/bin; do
  PATH="$PATH:$d"
done

(You don't need to repeat export: when a variable is exported, it stays exported, and modifications are reflected in the environment).

If you create new directories under tools, this will not be reflected in your ongoing session, only the next time .profile is read. If this is not satisfactory, you can use a different approach: put a single directory such as ~/bin in your PATH, and when you install software, create symbolic links in ~/bin. Stow (or its alternative XStow) is a good way of doing this; see Keeping track of programs for an overview of how this works.

Answer 2

Adding things to the $PATH is not recursive. Only the directories that are present in $PATH will be searched by your shell when it's looking for executables to run.

To see what's currently on your $PATH:

$ printenv PATH

4 common tactics when dealing with many directories such as you're facing is to either:

1. add them individually, which is perfectly fine, $PATH can be fairly long.
2. use the command alternatives (man page) to create symbolic links to the various executables in the differing directories. This trades a long $PATH for having to maintain symbolic links to the various executables.
3. create either aliases or wrapper .sh scripts that can exist in a common directory and will dynamically change the $PATH or other environment variables as needed.
4. Use a tool to manage your environment such as modules.

Further background

Where I used to work we used a technology we developed internally called use scripts which operators would run commands such as use X, where X was the name + version of a CAD/CAM software package such as Xilinx. This would automatically add the appropriate directories and environment variables to the user's shell. When they were done with X they could say use -no X. to unload this tool from their environment.

More exotic methods

Another approach for building up your $PATH but in a more modular way would be to mimic the way most systems work by creating a /etc/profile.d directory. You can make your own, or even utilize your system's /etc/profile.d directory to facilitate the adding of things to your environment and/or $PATH.

For example, if you look at your /etc/bashrc you might notice this construct:

for i in /etc/profile.d/*.sh; do
    if [ -r "$i" ]; then
        if [ "$PS1" ]; then
            . "$i"
        else
            . "$i" >/dev/null
        fi
    fi
done

You could model yourself something similar where you could put fragments of things you want to get added to your $PATH + environment.

When this loop runs it will incorporate the contents of the various files in your version of the profile.d directory. You'd just need to create files in your directory with content like this:

file1.sh

PATH=$PATH:$HOME/tools/tool1/bin

file2.sh

PATH=$PATH:$HOME/tools/tool2/bin

You can organize this directory anyway you want.

Answer 3

No that will not work ! that will add only $HOME/tools to your path.

The principle of each tool having it's own bin dir doesn't fit well really, think about /bin or /usr/bin everything goes in there (well nearly everything) each package does not have it's own bin dir. ( Orthogonal ? )

Answer 4

You could do either of the following

1. Just add all the bin folders like you have done

2. Create another bin folder such as $HOME/bin, and then symbolic link the relevant binaries into $HOME/bin, and then add $HOME/bin to your path

3. If you have admin rights to the machine, then use /usr/local for you application compilations, and then everything be in place automatically, and you don't need to change your path at all. i.e. ./configure on it's on will automatically make sure that the application will install in /usr/local

4. Use something like modules environment http://modules.sourceforge.net/, which then you can add to your environment, and depending the application you want to run, then you can change the environment.

I hope that makes sense.

Answer 5

Try this way:
export PATH="$PATH:$(du "~/tools/" | cut -f2 | tr '\n' ':' | sed 's/:*$//')"
This will add ~/tools itself along with all its subdirectories into $PATH
Explanation:
- du will display all the subdirectories info each line
- cut -f2 will extract the second column, i.e., the names of the subdirectories
- tr '\n' ':' will change each link break into a colon. This will join all lines into a single line and the subdirectories are delimited by a colon
- sed 's/:*$//' will remove the last colon