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From: heiko@methan.chemie.fu-berlin.de (Heiko Schlichting)
Newsgroups: comp.unix.programmer
Subject: Re: Awk
Message-ID: <8XTOBQT@methan.chemie.fu-berlin.de>
Date: 8 Mar 91 00:41:55 GMT
References: <1991Mar7.115420.21315@daimi.aau.dk> <31137@shamash.cdc.com>
Reply-To: admin@methan.chemie.fu-berlin.de
Organization: Free University of Berlin, Organic Chemistry
Lines: 35

mek@michael.udev.cdc.com (Mark Kennedy) writes:
>ezra@daimi.aau.dk (Thomas Ravnholt) writes:

>> If I want to run a unix-command in an awk-script,
>> how do I get the output into a variable.
>> 
>>   I tried 
>>     getline < system(unixcommand)
>>      system(unixcommand | getline)
>>
>> but it is no good of course. system returns 0 or 1 and
>> not the output of the unixcommand.
 
>Crude, but effective, temporary files are your friend.  Here's a
>simple example that does what you ask.
>
>#! /bin/sh
>
>awk '
>BEGIN {
>system("date > /tmp/foo")
>getline X < "/tmp/foo"
>print X
>}'

Using GNU-awk 2.11.1 it is easier with:

awk 'BEGIN{ "date"|getline X; close("date"); print X}' /dev/null

Bye, Heiko.
-- 
 |~|    Heiko Schlichting                   | Freie Universitaet Berlin 
 / \    heiko@fub.uucp                      | Institut fuer Organische Chemie
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