SUMMARY: Script help with read

Thanks to:

Chris Schroen
Christ Clark
Michael DeSimone
Matthew Stier
David DEAVES
SteinAxt
Rob McMahon
John F Wall
Alex Stade
John Julian
Stephen Barnett
John Leadeham
Damir Delija
Mats Oberg
Jonathan Birchall
Alan Crosby
Hutin Bertrand
Doc G (Tim)
Luc Suryo
Thad MacMillan
Reggie Beavers

The problem with the original script was that read was running in a
subshell and the variables do not survive when it closes. ksh handles this
differently than sh and bash which are the shells I tested before posting.
David Deaves and Christ Clark said it well "In bourne shell (/bin/sh) the
head of the pipeline is the current shell, and the tail is a sub shell. So
in this case, the sub shell happily evaluates the input and allocates it to
it's environment variables, then exits." and "Being part of a pipe, the
'read' is executed in a subshell. The variables it sets are lost when the
subshell terminates and not propagated back to the parent shell."

The solution for sh I chose to use is from Chris Schroen and it is to use
set and then the positional parameters ($1 $2 ..$9) to pull the data that I
wanted. 

#!/bin/sh
while read i
do
        set `quota -v $i | tail -1`
        mailx -s "subject line" -r address $i <<EOT

You have $5 $6 left until your mail will stop being delivered to your
mailbox. Your quota is $3 Kb and you
r current usage is $2 Kb.
EOT
done </usr/local/tools/gtest.users

A variation on this is:

line="`quota -v $i | tail -1`"
set - $line
fs=$1; usage=$2; etc...

Another solution add a while/do:

#!/bin/sh
for i in `cat /usr/local/tools/gtest.users` ; do
 
      quota -v $i | tail -1 | while read fs usage qta limit time left files
quota limit1
          do
              mailx -s "subject line" -r address $i <<EOT
 
You have $time $left left until your mail will stop being delivered to your
mailbox. Your quota is $qta Kb and you
r current usage is $usage Kb.
EOT
          done
done


Another workaround is to run everything in a subshell,

for ...; do
	quota -v $i | tail -1 | ( read fs usage qta limit time left files
            mailx -s "subject line" -r address $i <<EOT
You have $time $left left until your mail will stop being delivered to your
mailbox. Your quota is $qta Kb and you
r current usage is $usage Kb.
EOT
	)
done

A couple of web sites recommended with good info on scripting:

http://www.unixguide.net/
http://laku19.adsl.netsonic.fi/era/unix/award.html

Mats Oberg and Alex Stade sent versions in Perl. I have not tested them.

#!/path/to/perl


$name=$ARGV[0];
if ( $name eq "" ) {die "Usage: $0 <filesystem>\n";}

open(QUOTA,"/usr/sbin/repquota $name |") or die "Unable to execute the
repquota command...\n";
$i=0;
print "$name \n";
while(<QUOTA>)
        {
        @A=split;
        if( $A[1]=~/\+\-/ ) {
                if ( $A[5]=~/EXPIRED/ ) {
                        open(MAIL,"|mailx -s \"$A[0], Your quota gracetime
has expired\" $A[0]");
                        print MAIL "You have exceeded the quota limit for
your unix home-directory. \nThe limit of your home-directory is: $A[3] kb,
you currently occupy: $A[2] kb\n\n";
                        print MAIL "The gracetime has expired, until you
have decreased the data to less than $A[3] kilobytes, you can no longer
write anything to your home-directory.\n(If you can't remove enough data on
your own, please contact the helpdesk)\n";
                        }
                elsif ( $A[5]=~/NOT/ ) {
                        open(MAIL,"|mailx -s \"$A[0], is over the quota
limit\" obergmat");
                        print MAIL "You still have time to decrease the
amount of data.\nWhen the gracetime expires you will not be able to write
anything to your home-directory.\n(You could possibly be thrown out and be
unable to log in.)\n";
                        }
                else {
                        open(MAIL,"|mailx -s \"$A[0], You are over the
quota limit\" $A[0]");
                        print MAIL "You have exceeded the quota limit for
your unix home-directory. \nThe limit of your home-directory is: $A[3] kb,
you currently occupy: $A[2] kb\n\n";
                        print MAIL "You still have $A[5] $A[6] to decrease
the amount of data.\nWhen the gracetime expires you will not be able to
write anything to your home-directory.\n(You could possibly be thrown out
and be unable to log in.)\n";
                        }
                print MAIL "\n\nFor more info about quotas see
http://some.adress.com    ---- Servicedesk tel: our phonenr...\n\n";
                close(MAIL);
                }
        }
close(QUOTA);


#!/usr/bin/perl -w

$file = "/usr/local/tools/gtest.users";

die "Can't open $file: $!\n"
         unless open (FILE, "$file");

while ($line = <FILE>)
{
         chomp $line;
         my @junk = `quota -v $line`;
         @quota = split (/\s+/, $junk[2]);
         if ($quota[1] >= $quota[2])
         {
                 open (MAIL, "| Mail \"Your account on Muse is 
over-quota\" $line");
                 print MAIL "You are over your quota on Muse. You are 
currently in the grace period which still allows for delivery of your 
e-mail. Please remove files or delete old mail.  Lack of action will 
result in lost e-mail and the inability to upload files to your account. 
You have $quota[5] day(s) left until your e-mail will stop being 
delivered to your mailbox.\nThe Helpdesk can be reached at (661) 
253-7887 or at helpdesk\@calarts.edu.\nThank you.";
         }
}


A few others gave general tip s for scripting which I will keep for future
reference. Thanks again to all who replied.


Original message:

>Below is a script I am trying to make work but I just can't seem to make it
>right. The purpose is to send an e-mail to a user who is over their quota
>and still in the grace period to alert them. I want to include some user
>specific details like timeleft usage and quota. The catted file is just
>some test names I set up.
>
>I do not seem to get any values using read. Everything seems to be null.
>This user is over-quota (I made it so). Below is the output to quota -v
>user. The echos were just to test the vars. Solaris 8. Any help would be
>appreciated.
>
>#!/bin/sh
>
> for i in `cat /usr/local/tools/gtest.users` ; do
>
>        quota -v $i | tail -1 | read fs usage qta limit timeleft files
>quota limit1
>
>        echo "$REPLY"
>        echo "$fs"
>        echo `$usage`
>        echo '$qta'
>        echo ${limit}
>        echo $timeleft
>        echo $files
>        
>        mailx -s "Your account on Muse is over-quota" -r
>helpdesk@calarts.edu $i <<EOT
>
>You are over your quota on Muse. You are currently in the grace period
>which still allows delivery of your e-mail. Please remove files or delete
>old mail. Lack of action will result in lost e-mail and the inability to
>upload files to your account. You have $timeleft left until your mail will
>stop being delivered to your mailbox.
>
>The Helpdesk can be reached at 661 253 7887 or at helpdesk@calarts.edu.
>Thank you.
>
>EOT
>
>done
>
>
>
># quota -v jcraford
>Disk quotas for jcraford (uid 2709):
>Filesystem     usage  quota  limit    timeleft  files  quota  limit
>timeleft
>/export        25734  20000  55000    6.9 days     73      0      0

-- 

Karyn Williams
Network Services Manager
California Institute of the Arts
karyn@calarts.edu
http://www.calarts.edu/network
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