[Discuss-gnuradio] GRC request

[Michael Dickens]

I would like to be able to execute GRC from a directory structure  
moved elsewhere from ${prefix} ... meaning, I compile and install into  
${prefix}, but then 'cp -r' or 'mv' or 'tar - | tar -' the whole  
directory structure elsewhere outside of the usual execution  
location.  I then create / modify the environment variables such that  
they point to the new location (PATH, PYTHONPATH, and  
DYLD_LIBRARY_PATH are the 3 primary ones for OSX).  From my initial  
testing, the rest of GNU Radio can do this with just those 3 variables  
(on OSX; Y-Variables-MV on other platforms)

This doesn't work because GRC hard-wires the install path (or  
something like it) in a few files (I do not know if all of these files  
need to be modified to get what I'd like to do working; nor do I know  
if these are all of the files that need to be tweaked):

grc/freedesktop/grc_setup_freedesktop.in
grc/src/platforms/base/Constants.py.in
grc/src/platforms/python/Constants.py.in

I can think of two possible solutions:

1) Put a switch at the top of each of these files along the lines of:

import os
DATA_DIR = os.getenv ("GRC_DATADIR")
if not DATA_DIR:
  DATA_DIR = @datadir@

or the equivalent functionality that would work for the @variables@  
used in that file (I don't know if the above would work; it is for  
descriptive purposes only): first check the user's shell environment  
for the appropriate variables, and if they don't exist, then revert to  
the default from compiling.  This way, users who wish to change the  
location can do so easily via their shell environment, and those who  
do not set the shell environment variables get the default -- same as  
current usage.

2) Even better would be the use of relative paths (it does work for  
me, directly modifying the installed files).  This solution would  
require knowing the path to $sharedir and the $pythondir and then  
figuring out how to get from one to the other (the relative path), but  
IMHO is the more elegant solution.

Thanks in advance! - MLD