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Top Forums Shell Programming and Scripting Strange behaviour of arrays in awk Post 302852379 by ripat on Wednesday 11th of September 2013 12:46:09 PM
Old 09-11-2013
Quote:
Originally Posted by Scrutinizer
This is not only a condition, but it also creates an array element code[$3] with an empty value
Indeed and that's exactly what I find weird. With code[$3] in the second block I was expecting awk to *evaluate* the value of code[$3] *not* to assign any value to it, albeit NULL.

Code:
awk 'foo="bar"{print "block 1"} END{print foo}' f1

Returns bar.

foo="bar" assigns "bar" to foo and returns a TRUE. No problem with that. But in the condition of the second block code[$3] there is no assignment sign and it still assigns a value. I can't stop finding it weird.

Furthermore, if you look to my code above and its return.

Code:
FNR == NR && /file1_l1/ {
	code[$2] = 1
	next
}

code[$3] {
	print
}

Code:
code[file1_l3_c3]=
code[code_to_find]=1
code[file2_code3]=
code[file1_l2_c3]=
code[file2_code5]=

The instruction next should make the program to loop on the first file until it reaches the end of file1. Then it continues with the second file, right? I understand that the condition of the second block assigns a value while evaluating code[$3] but how come that it assigns values from the first file as the pointer NR is already on the second file? See my point?

Last edited by ripat; 09-11-2013 at 02:36 PM.. Reason: More confusion...
 
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Locale::Codes::LangExt(3pm)				 Perl Programmers Reference Guide			       Locale::Codes::LangExt(3pm)

NAME
Locale::Codes::LangExt - standard codes for language extension identification SYNOPSIS
use Locale::Codes::LangExt; $lext = code2langext('acm'); # $lext gets 'Mesopotamian Arabic' $code = langext2code('Mesopotamian Arabic'); # $code gets 'acm' @codes = all_langext_codes(); @names = all_langext_names(); DESCRIPTION
The "Locale::Codes::LangExt" module provides access to standard codes used for identifying language extensions, such as those as defined in the IANA language registry. Most of the routines take an optional additional argument which specifies the code set to use. If not specified, the default IANA language registry codes will be used. SUPPORTED CODE SETS
There are several different code sets you can use for identifying language extensions. 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 = code2langext('acm','alpha'); $lext = code2langext('acm',LOCALE_LANGEXT_ALPHA); The codesets currently supported are: alpha This is the set of three-letter (lowercase) codes from the IANA language registry, such as 'acm' for Mesopotamian Arabic. This is the default code set. ROUTINES
code2langext ( CODE [,CODESET] ) langext2code ( NAME [,CODESET] ) langext_code2code ( CODE ,CODESET ,CODESET2 ) all_langext_codes ( [CODESET] ) all_langext_names ( [CODESET] ) Locale::Codes::LangExt::rename_langext ( CODE ,NEW_NAME [,CODESET] ) Locale::Codes::LangExt::add_langext ( CODE ,NAME [,CODESET] ) Locale::Codes::LangExt::delete_langext ( CODE [,CODESET] ) Locale::Codes::LangExt::add_langext_alias ( NAME ,NEW_NAME ) Locale::Codes::LangExt::delete_langext_alias ( NAME ) Locale::Codes::LangExt::rename_langext_code ( CODE ,NEW_CODE [,CODESET] ) Locale::Codes::LangExt::add_langext_code_alias ( CODE ,NEW_CODE [,CODESET] ) Locale::Codes::LangExt::delete_langext_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.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) 2011-2012 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::Codes::LangExt(3pm)

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