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Full Discussion: Bash variable expansion
Top Forums Shell Programming and Scripting Bash variable expansion Post 302997736 by jcdole on Thursday 18th of May 2017 04:03:25 PM
Old 05-18-2017
Bash variable expansion
Hello.
The file /etc/fstab contains
Code:
UUID=957c3295-9944-1593-82e2-2b90dede4312 /                     ext4       noatime,discard,acl,user_xattr        1 1

I fill a variable
Code:
SOME_LINE=$( cat /etc/fstab | grep \/\..*ext4 | grep noatime,discard )

echo $SOME_LINE
Code:
UUID=957c3295-9944-1593-82e2-2b90dede4312 / ext4 noatime,discard,acl,user_xattr 1 1

echo ${SOME_LINE}
Code:
UUID=957c3295-9944-1593-82e2-2b90dede4312 / ext4 noatime,discard,acl,user_xattr 1 1

echo "$SOME_LINE"
Code:
UUID=957c3295-9944-1593-82e2-2b90dede4312 /                     ext4       noatime,discard,acl,user_xattr        1 1

I would like to know why The 3 outputs are not the same.

Thank you for helping.
Last edited by jcdole; 05-18-2017 at 06:51 PM..
 

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LEARN ABOUT CENTOS

locale::codes::langext

Locale::Codes::LangExt(3)				User Contributed Perl Documentation				 Locale::Codes::LangExt(3)

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) 2011-2013 Sullivan Beck

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

perl v5.16.3							    2013-02-27						 Locale::Codes::LangExt(3)
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