Help with awk

Les Mikesell lesmikesell at gmail.com
Fri Feb 23 01:09:37 UTC 2007


aragonx at dcsnow.com wrote:
> I bet awk has it's own user list but before I go and subscribe to another
> one, I figured I would ask here first.  I have the following awk code that
> is trying to set a variable of the shell it is running in.  It doesn't
> work and I've searched high and low to see how to get it to do so.
> 
> The reason I don't just use DOMAIN= 'awk blah blah blah' is I want to set
> more than one shell variable for each record.  But I have to get this
> working first.  :(
> 
> #!/bin/bash
> 
> awk '{FS=":"}{system ("DOMAIN=" $1); }
>         {system ("DOMAIN="$1)};
>         {system ("echo \"$DOMAIN\"")};
> ' /etc/passwd
> 
> Any help would be appreciated.

This isn't an awk question, it's a 'how unix works' question.  A child 
process can't change anything in it's parent's environment.  Your awk 
program will be a child of the shell running it; the system statements 
run yet another shell as a child under awk.  All of those processes have 
their environment strings in protected memory (inherited shared but 
copy-on-write).


The var=`command ..` will work, or you can do all of the work that needs 
the setting in the lowest level subprocess that has the right values.

-- 
   Les Mikesell
    lesmikesell at gmail.com




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