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Full Discussion: Change existing variable value only user enters non-empty string.
Top Forums Shell Programming and Scripting Change existing variable value only user enters non-empty string. Post 302422951 by kchinnam on Wednesday 19th of May 2010 09:25:11 PM
Old 05-19-2010
This script works.. But I am not sure why its working..
I thought [ -n string ] is supposed to check for zero length string. But in my case even a uninitialized variable has 1 byte length..

Code:
#!/usr/bin/ksh
uid="scott"
# Assign new value user enters to uid, else leave it alone.

echo "Value of \${resp} --> "; echo "${resp}" | od -bcx
echo "Length of \${resp} --> \c"; echo ${resp} | wc -C

echo "Press Enter to select existing value \r\n"
echo "uid[${uid}]: \c"; read resp;

echo "Value of \${resp} --> "; echo "${resp}" | od -bcx
echo "Length of \${resp} --> \c"; echo ${resp} | wc -C

# if user changes uid to something, then only change original value.
if [ -n "${resp}" ]; then
  echo "${resp}" | od -bcx
  # I do not want to capture "Enter" or space characters into this.
  uid=${resp}
fi
echo "uid --> ${uid}"

Can someone explain why every empty variable has following bytes? with byte length 1.?

Code:
> test.sh   
Value of ${resp} --> 
0000000 012
          \n
            0a00
0000001
Length of ${resp} -->        1
Press Enter to select existing value 

uid[scott]: 
Value of ${resp} --> 
0000000 012
          \n
            0a00
0000001
Length of ${resp} -->        1
uid --> scott

Last edited by kchinnam; 05-19-2010 at 10:31 PM.. Reason: elaboration
 

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LEARN ABOUT OSX

net::ldap::control::passwordpolicy

Net::LDAP::Control::PasswordPolicy(3)			User Contributed Perl Documentation		     Net::LDAP::Control::PasswordPolicy(3)

NAME

       Net::LDAP::Control::PasswordPolicy - LDAPv3 Password Policy control object

SYNOPSIS

	use Net::LDAP;
	use Net::LDAP::Control::PasswordPolicy;
	use Net::LDAP::Constant qw( LDAP_CONTROL_PASSWORDPOLICY );

	$ldap = Net::LDAP->new( "ldap.example.com" );

	$pp = Net::LDAP::Control::PasswordPolicy->new;

	$mesg = $ldap->bind( "cn=Bob Smith,dc=example,dc=com",
			     password => "secret",
			     control => [ $pp ] );

	# Get password policy reponse
	my($resp)  = $mesg->control( LDAP_CONTROL_PASSWORDPOLICY );

	if (defined($resp)) {
	  my $v = $resp->pp_error;
	  print "Password policy error $v
" if defined $v;
	  $v = $resp->time_before_expiration;
	  print "Password expires in $v second(s)
" if defined $v;
	}

DESCRIPTION

       "Net::LDAP::Control::PasswordPolicy" provides an interface for the creation and manipulation of objects that represent
       "PasswordPolicyRequest"s and "PasswordPolicyResponse"s as described by draft-behera-password-policy-09.

       This control can be passed to most operations, including the bind.

CONSTRUCTOR ARGUMENTS

       There are no constructor arguments other than those provided by Net::LDAP::Control.

METHODS

       time_before_expiration
	   If defined, this is an integer value holding the time left in seconds before the account's password will expire.

       grace_authentications_remaining
	   If defined, this is an integer value holding the number of authentication requests allowed before the account is locked.

       pp_error
	   If defined, this contains a more detailed error code for the account.  See Net::LDAP::Constant for definitions of each.  Values can
	   include:

	   LDAP_PP_PASSWORD_EXPIRED
	   LDAP_PP_ACCOUNT_LOCKED
	   LDAP_PP_CHANGE_AFTER_RESET
	   LDAP_PP_PASSWORD_MOD_NOT_ALLOWED
	   LDAP_PP_MUST_SUPPLY_OLD_PASSWORD
	   LDAP_PP_INSUFFICIENT_PASSWORD_QUALITY
	   LDAP_PP_PASSWORD_TOO_SHORT
	   LDAP_PP_PASSWORD_TOO_YOUNG
	   LDAP_PP_PASSWORD_IN_HISTORY

SEE ALSO

       Net::LDAP, Net::LDAP::Control, Net::LDAP::Constant, draft-behera-ldap-password-policy-09.txt

AUTHOR

       Chris Ridd <chris.ridd@isode.com>

       Please report any bugs, or post any suggestions, to the perl-ldap mailing list <perl-ldap@perl.org>

COPYRIGHT

       Copyright (c) 2008 Chris Ridd. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.

perl v5.16.2							    2012-09-20				     Net::LDAP::Control::PasswordPolicy(3)
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