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Full Discussion: [bash] wanted: function with a clean way for multiple return values
Top Forums Shell Programming and Scripting [bash] wanted: function with a clean way for multiple return values Post 302977180 by Don Cragun on Wednesday 13th of July 2016 03:16:56 PM
Old 07-13-2016
In addition to the sage advice bakunin provided, the following code in your _exec function seem to demonstrate a misunderstanding of how parameter expansions work in the shell:
Code:
        local CMD=$1
        local OUT="$( $CMD 2>&1 ;echo "||$?" )"
        local EXIT_CODE="${OUT##*||}"

        # if no output is there at all [[:space:]]* does
        # not match. So do one with space and one without

        OUT="${OUT%[[:space:]]*||[0-9]*}"
        OUT="${OUT%||[0-9]*}"
        OUT="${OUT:-<EMPTY>}"

In the four shell parameter expansions:
Code:
${var%pattern}
${var%%pattern}
${var#pattern}
${var##pattern}

pattern is a filename matching pattern; not a regular expression. To get rid of the last || followed by any string of characters from the end of the variable var, you just need:
Code:
output=${out%||*}

or (given the way you assign values to the variable out):
Code:
output=${out%||$EXIT_CODE}

should produce identical results.

You then seem to be trying to strip off trailing whitespace characters from the output produced by running $CMD 2>&1 and, after doing that, to change an empty string to the non-empty string EMPTY. But, I have no idea why that is something you would want to do??? And, if that is something you want to do, that is not the way to do it.
 

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LEARN ABOUT MOJAVE

locale::codes::langfam5.18

Locale::Codes::LangFam(3pm)				 Perl Programmers Reference Guide			       Locale::Codes::LangFam(3pm)

NAME

       Locale::Codes::LangFam - standard codes for language extension identification

SYNOPSIS

	  use Locale::Codes::LangFam;

	  $lext = code2langfam('apa');		       # $lext gets 'Apache languages'
	  $code = langfam2code('Apache languages');    # $code gets 'apa'

	  @codes   = all_langfam_codes();
	  @names   = all_langfam_names();

DESCRIPTION

       The "Locale::Codes::LangFam" module provides access to standard codes used for identifying language families, such as those as defined in
       ISO 639-5.

       Most of the routines take an optional additional argument which specifies the code set to use. If not specified, the default ISO 639-5
       language family codes will be used.

SUPPORTED CODE SETS

       There are several different code sets you can use for identifying language families. 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:

	  $lext = code2langfam('apa','alpha');
	  $lext = code2langfam('apa',LOCALE_LANGFAM_ALPHA);

       The codesets currently supported are:

       alpha
	   This is the set of three-letter (lowercase) codes from ISO 639-5 such as 'apa' for Apache languages.

	   This is the default code set.

ROUTINES

       code2langfam ( CODE [,CODESET] )
       langfam2code ( NAME [,CODESET] )
       langfam_code2code ( CODE ,CODESET ,CODESET2 )
       all_langfam_codes ( [CODESET] )
       all_langfam_names ( [CODESET] )
       Locale::Codes::LangFam::rename_langfam  ( CODE ,NEW_NAME [,CODESET] )
       Locale::Codes::LangFam::add_langfam  ( CODE ,NAME [,CODESET] )
       Locale::Codes::LangFam::delete_langfam  ( CODE [,CODESET] )
       Locale::Codes::LangFam::add_langfam_alias  ( NAME ,NEW_NAME )
       Locale::Codes::LangFam::delete_langfam_alias  ( NAME )
       Locale::Codes::LangFam::rename_langfam_code  ( CODE ,NEW_CODE [,CODESET] )
       Locale::Codes::LangFam::add_langfam_code_alias  ( CODE ,NEW_CODE [,CODESET] )
       Locale::Codes::LangFam::delete_langfam_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.loc.gov/standards/iso639-5/id.php
	   ISO 639-5 .

AUTHOR

       See Locale::Codes for full author history.

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

COPYRIGHT

	  Copyright (c) 2011-2013 Sullivan Beck

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

perl v5.18.2							    2013-11-04					       Locale::Codes::LangFam(3pm)
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