exported functions shell scripting

Most shells support "exported functions". For example, in the Bourne shell, you use "export -f", and ksh is "typeset -xf". But these are confusing:

If you define foo within your .kshrc (or whatever $ENV points at), the function is available at the command line to any invocation of ksh.

If you then mark it for export (typeset -xf foo), it becomes available to scripts, but it STILL not available to scripts beginning with #!/bin/ksh.

It is THAT part that is the source of the mind-boggling confusion: you can obviously see that as new ksh has the function, yet it won't work in a script that begins with #!/bin/ksh . The script does not have the function, as can easily be seen by putting "functions" into such a script: functions listed in /.kshrc will not be there.

However- if you both define AND mark the function for export within the $ENV file, it then IS available to those scripts.

# kshrc
function foo 
{
echo "Hi there!"
}

typeset -xf foo
 

The reason these exported functions aren't usuaslly available to scripts beginning with #! is because the kernel doesn't propogate them when it execs the script. Scripts without #! are forked, and the function would be passed.

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