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356

answers:

3

I am writing a little install script for some software. All it does is unpack a target tar, and then i want to permanently set some environment variables - principally the location of the unpacked libs and updating $PATH. Do I need to programmatically edit the .bashrc file, adding the appropriate entries to the end for example, or is there another way? What's standard practice?

Edit: The package includes a number of run scripts (20+) that all use these named environment variables, so I need to set them somehow (the variable names have been chosen such that a collision is extremely unlikely)

+2  A: 

Standard practice is to install into directories already in the path and in the standard library directory, so there is no need to update these variables.

Updating .bashrc is a bit failure-prone, among other things; what if a user uses a different file or shell?

WhirlWind
+1 correct. Users would be very unhappy if you tried to edit their .bashrc for them. If you want to install into a non-standard directory - or don't think your user will have the permission to - let them specify `--install-dir=mydir` and tell them what they'd need to add to their environment. There is a good example at http://golang.org/doc/install.html
msw
yes, i thought that editing .bashrc would be dubious for a number of reasons. The problem is the software contains a number of scripts (20+) that all use these named environment variables - so i need to set them somehow.
Richard
One way is to source them in a wrapper script that calls your scripts.
WhirlWind
+6  A: 

LSB-compliant (see spec) practice is to create a shell script in /etc/profile.d/ folder.

Name it after your application (and make sure that the name is unique), make sure that the name ends with .sh (you might want to add scripts for other shells as well) and source the variables you need in the script. All *.sh scripts from that directory are read at user login--the same time /etc/profile is sourced.

Note that this is not enforced by bash; rather, it's an agreement of sorts.

Pavel Shved
ok this looks like it might be the solution. presumably the installer will need to be run as root in order to write an executable script here.
Richard
+2  A: 

You can also generate and install a script that sets those variables. Users of your package then source that script or copy its contents to their own shell init file.

lhf
Or a wrapper script calls the var-setting script at a known name and place and then calls the initial executable.
Dennis Williamson