Re: selecting into unix variable

From: Ian Parkin <twod_at_tdl.com>
Date: 1995/11/01
Message-ID: <476orl$vh0_at_news.tdl.com>#1/1

[Stuff about a magic value of 256 deleted]

: There are Unix limits to the size of variables - and they differ : between flavours.

I hope you don't mean that there is a 256 character limit to Unix variables !

I think the 256 limit should, in fact, be 255 which indicates the maximum value that ${?} or ${status} can hold.

A quick example :

#!/bin/sh
if [ -f 1 -o -f 2 -o -f 3 ]
then

        echo "Yoiks can't run a target file exists"
        exit 1

fi

echo 'exit 255' > 1
echo 'exit 256' > 2
echo 'exit 257' > 3

chmod +x 1 2 3
./1

echo ${?}
./2

echo ${?}
./3

echo ${?}
/bin/rm -f 1 2 3
exit 0  

• snip --

The expected output of the above is :

255
0
1

IAP Received on Wed Nov 01 1995 - 00:00:00 CET