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Full Discussion: Sed command help (appending)
Top Forums Shell Programming and Scripting Sed command help (appending) Post 302685831 by Don Cragun on Monday 13th of August 2012 11:58:18 AM
Old 08-13-2012
Quote:
Originally Posted by RudiC
@Don Cragun: Thanks for drawing the attention to these aspects. As I said, tinkering with system files is always a thing to consider twice.
Btw, you should add a s/:,/:/ to your sed cmd in case $Usr would be the first in $Grp.
Good catch. And doing that in the ed script would be something like:
Code:
ed -s /etc/group <<-EOF
	/^$Grp:/s/$/,$Usr/p
	.g/:,$Usr$/s//:$Usr/p
	w
	q
EOF

with the .g needed in front of the second s command to preserve the 0 exit status if $Grp was found and $Usr wasn't the first user in the group.

One should also make sure that the script isn't adding a user to the "nobody" group nor the "nogroup" group (or other groups depending on the OS on the machine), but I didn't bother because the idea of editing /etc/passwd, /etc/group, or any corresponding shadow files because usermod won't work (without explaining why usermod won't work) still just seems wrong. Smilie
 

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IO::All::HTTP(3pm)					User Contributed Perl Documentation					IO::All::HTTP(3pm)

NAME
IO::All::LWP - Extends IO::All to HTTP URLs SYNOPSIS
use IO::All; $content < io('http://example.org'); # GET webpage into scalar io('http://example.org') > io('index.html'); # GET to file "hello " > io('http://example.org/index.html'); # PUT webpage # two ways of getting a page with a password: $content < io('http://me:secret@example.org'); $content < io('http://example.org')->user('me')->password('secret'); DESCRIPTION
This module extends IO::All for dealing with HTTP URLs. Note that you don't need to use it explicitly, as it is autoloaded by IO::All whenever it sees something that looks like an HTTP URL. The SYNOPSIS shows some simple typical examples, but there are many other interesting combinations with other IO::All features! For example, you can get an HTTP URL and write the content to a socket, or to an FTP URL, of to a DBM file. METHODS
This is a subclass of IO::All::LWP. The only new method is "http", which can be used to create a blank IO::All::HTTP object; or it can also take an HTTP URL as a parameter. Note that in most cases it is simpler just to call io('http://example.com'), which calls the "http" method automatically. OPERATOR OVERLOADING
The same operators from IO::All may be used. < GETs an HTTP URL; > PUTs to an HTTP URL. SEE ALSO
IO::All, IO::All::LWP, LWP. AUTHORS
Ivan Tubert-Brohman <itub@cpan.org> and Brian Ingerson <ingy@cpan.org> COPYRIGHT
Copyright (c) 2007. Ivan Tubert-Brohman and Brian Ingerson. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See <http://www.perl.com/perl/misc/Artistic.html> perl v5.10.0 2007-03-29 IO::All::HTTP(3pm)
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