bash $X++ sintax

[Neil Watson]

On Thu, May 25, 2006 at 03:10:41PM -0400, Chris F.A. Johnson wrote:
>>  What about the perl
>>operator .= ?
>
>     What does that do?

That is the equivalent to ++ only for strings.  Example:
$X = "foo";
$Y = "bar";

$word = $X;
$word .= $Y;

print $word

foobar

I think I have it figured out but I'm still missing something.  Consider
this script:

#!/bin/bash

# User prefix
USER="sftp"

# Number or users
NUM=5

# Email report recipient
RECIP="nhwatson-CDzewpS4IfcWRvO7F5PPEFaTQe2KTcn/@public.gmane.org"

# Mail messages
MSG="Transfer passwords for today (`date`):"

# Generate passwords for all users
apg -m 10 -M CN -n ${NUM} | {

    while read PW; do

       X=$(( $X + 1 ))

       # Username will be USER+NUM e.g. sftp1
       USERNAME=${USER}${X}

       # Set password for user
       echo $PW | passwd -u $USERNAME --stdin

       # Log change for later email
       MSG="${MSG} User: $USERNAME Password; $PW"

   done
}

echo $MSG #| mail -s "SSH Transfer Password Updates" $RECIP
exit 0

MSG is as expect until is finishes the code block.  After that it is reset to
its original state.  It's like MSG is scoped differently inside the code block.
I am not aware that bash is scope conscious.

- 
Neil Watson             | Gentoo Linux
System Administrator    | Uptime  15:17:35 up  9:09,  2 users,  load average: 0.00, 0.00, 0.00
http://watson-wilson.ca | 2.6.11.4 AMD Athlon(tm) MP 2000+ x 2
--
The Toronto Linux Users Group.      Meetings: http://tlug.ss.org
TLUG requests: Linux topics, No HTML, wrap text below 80 columns
How to UNSUBSCRIBE: http://tlug.ss.org/subscribe.shtml