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Full Discussion: Checking for null condition in a UNIX variable
Top Forums Shell Programming and Scripting Checking for null condition in a UNIX variable Post 302827911 by rafa_fed2 on Monday 1st of July 2013 05:29:10 AM
Old 07-01-2013
Checking for null condition in a UNIX variable
i have this code
Code:
for i in `cat sql_output.txt`
do
-- some script commands
done

sql_output.txt has 1 column with employee_ids
If the sql_output.txt is null then the do loop should not execute.
How can i implement this.

Code:
for i in `cat sql_output.txt`
If i is null or empty
then 
echo "no ids to execute"
else
do
-- some script commands
done


i should be checked for null condition only once..at the very beginning if is not null then it for loop should be executed
 

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LEARN ABOUT OSX

locale::script

Locale::Script(3pm)					 Perl Programmers Reference Guide				       Locale::Script(3pm)

NAME

       Locale::Script - standard codes for script identification

SYNOPSIS

	  use Locale::Script;

	  $script  = code2script('phnx');		      # 'Phoenician'
	  $code    = script2code('Phoenician'); 	      # 'Phnx'
	  $code    = script2code('Phoenician',
				 LOCALE_CODE_NUMERIC);	      # 115

	  @codes   = all_script_codes();
	  @scripts = all_script_names();

DESCRIPTION

       The "Locale::Script" module provides access to standards codes used for identifying scripts, such as those defined in ISO 15924.

       Most of the routines take an optional additional argument which specifies the code set to use. If not specified, the default ISO 15924
       four-letter codes will be used.

SUPPORTED CODE SETS

       There are several different code sets you can use for identifying scripts. A code set may be specified using either a name, or a constant
       that is automatically exported by this module.

       For example, the two are equivalent:

	  $script = code2script('phnx','alpha');
	  $script = code2script('phnx',LOCALE_SCRIPT_ALPHA);

       The codesets currently supported are:

       alpha, LOCALE_SCRIPT_ALPHA
	   This is a set of four-letter (capitalized) codes from ISO 15924 such as 'Phnx' for Phoenician.  It also includes additions to this set
	   included in the IANA language registry.

	   The Zxxx, Zyyy, and Zzzz codes are not used.

	   This is the default code set.

       num, LOCALE_SCRIPT_NUMERIC
	   This is a set of three-digit numeric codes from ISO 15924 such as 115 for Phoenician.

ROUTINES

       code2script ( CODE [,CODESET] )
       script2code ( NAME [,CODESET] )
       script_code2code ( CODE ,CODESET ,CODESET2 )
       all_script_codes ( [CODESET] )
       all_script_names ( [CODESET] )
       Locale::Script::rename_script  ( CODE ,NEW_NAME [,CODESET] )
       Locale::Script::add_script  ( CODE ,NAME [,CODESET] )
       Locale::Script::delete_script  ( CODE [,CODESET] )
       Locale::Script::add_script_alias  ( NAME ,NEW_NAME )
       Locale::Script::delete_script_alias  ( NAME )
       Locale::Script::rename_script_code  ( CODE ,NEW_CODE [,CODESET] )
       Locale::Script::add_script_code_alias  ( CODE ,NEW_CODE [,CODESET] )
       Locale::Script::delete_script_code_alias  ( CODE [,CODESET] )
	   These routines are all documented in the Locale::Codes::API man page.

SEE ALSO

       Locale::Codes
	   The Locale-Codes distribution.

       Locale::Codes::API
	   The list of functions supported by this module.

       http://www.unicode.org/iso15924/
	   Home page for ISO 15924.

       http://www.iana.org/assignments/language-subtag-registry
	   The IANA language subtag registry.

AUTHOR

       See Locale::Codes for full author history.

       Currently maintained by Sullivan Beck (sbeck@cpan.org).

COPYRIGHT

	  Copyright (c) 1997-2001 Canon Research Centre Europe (CRE).
	  Copyright (c) 2001-2010 Neil Bowers
	  Copyright (c) 2010-2012 Sullivan Beck

       This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

perl v5.16.2							    2012-10-11						       Locale::Script(3pm)
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