Emulate ksh's FPATH variable in bash

Shell Programming and Scripting
1

Over time i have developed a library of useful (ksh) functions which i use in most of my scripts. I use the ksh's FPATH variable to locate all these functions and use a standard environment-setting-function to always have the same environment in all my scripts.

Here is how i begin scripts:

#!/bin/ksh
# foo.ksh

# main()

if [ -z "$DEVELOP" ] ; then                      # set environment
     . /usr/local/lib/ksh/f_env
else
     . ~/lib/f_env
fi

# ... rest of code ....

$DEVELOP is a variable i set if i want to use a local copy of the function library for testing purposes. "/usr/local/lib/ksh/f_env" looks like this:

if [ -z "$NEVER_USE_THIS_VAR" ] ; then           # recursion protection
    # .... some more settings ...

    if [ -z "$DEVELOP" ] ; then
          typeset -x FPATH="/usr/local/lib/ksh"  # set fnc path for fnc lib
          FPATH="$FPATH:/usr/local/bin"
          FPATH="$FPATH:/usr/local/sbin"
     else
          typeset -x FPATH=~/lib                 # for lib development
     fi

     # ...
     typeset -x NEVER_USE_THIS_VAR="KILROY_WAS_HERE"
fi

This mechanism is quite handy because many functions in the library depend on other functions in the same library and this way all these depencies are solved automatically.

I would like to make this library compatible with the bash shell (ideally i would be able to use these functions from ksh and bash equally), but bash lacks the FPATH mechanism. I came up with the following solution, but obviously it is quite unsatisfactory and i wonder if there is a better way to achieve my goal:

(within f_env(), after setting the FPATH variable: )

                                                 # simulate FPATH for bash
     if [ -n "$BASH_VERSION" ] ; then
          IFS=:
          for fFPathDir in $FPATH ; do
               for fFFile in $fFPathDir/* ; do
                    if [ $( \
                            sed -n '/^$/d;/^#/!{p;q}' $fFFile |\
                            grep -c '^\(function \)*[^ ][^ ]* ()' \
                          ) -gt 0 ] ; then
                          echo $fFFile
                         . $fFFile
                    fi
               done
          done
     fi

Basically i circle through FPATH, look into every file and if the first non-comment-line begins with "function <some-name> ()" (this is the sed-grep-line) i parse it into the environment. This looks quite clumsy, unreliable and downright ugly, but with my limited knowledge of bash i was not able to find a better solution. Your suggestions are welcome.

bakunin

2

Try this bash hack to get FPATH:
/usr/share/doc/bash/examples/functions/autoload

3

Hi.

I have a version of this, and it worked correctly as far as I could tell, but it may have been a later version:

# The first cut of this was by Bill Trost, trost@reed.bitnet.
# The second cut came from Chet Ramey, chet@ins.CWRU.Edu
# The third cut came from Mark Kennedy, mtk@ny.ubs.com.  1998/08/25

cheers, drl

4

Many thanks, this is an interesting option to explore. I will need some time to evaluate and play around with it, but i will report here my results.

bakunin