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Full Discussion: Blog-Thread: Creating a Shell Wrapper and Runtime Modifier (SWARM)
Top Forums Shell Programming and Scripting Blog-Thread: Creating a Shell Wrapper and Runtime Modifier (SWARM) Post 303045307 by drl on Monday 16th of March 2020 07:10:46 AM
Old 03-16-2020
Hi.

Perhaps I missed something, but variables are created/set when from a function:
Code:
#!/usr/bin/env bash

# @(#) s1       Demonstrate use of option "-g" in "declare".

LC_ALL=C ; LANG=C ; export LC_ALL LANG
pe() { for _i;do printf "%s" "$_i";done; printf "\n"; }
pl() { pe;pe "-----" ;pe "$*"; }
em() { pe "$*" >&2 ; }
db() { ( printf " db, ";for _i;do printf "%s" "$_i";done;printf "\n" ) >&2 ; }
db() { : ; }
C=$HOME/bin/context && [ -f $C ] && $C

(
        declare -g my_test_a="a test"
        export my_test_b="an exported beer"
)

unset my_test_a my_test_b
pl " Results, not in function:"
echo $my_test_a
echo $my_test_b

f1 ()
{
    declare -g my_test_a="a test"
    export my_test_b="an exported beer"
}

unset my_test_a my_test_b
pl " Results, in function f1:"
f1
echo $my_test_a
echo $my_test_b

exit

producing:
Code:
$ ./s1

Environment: LC_ALL = C, LANG = C
(Versions displayed with local utility "version")
OS, ker|rel, machine: Linux, 3.16.0-7-amd64, x86_64
Distribution        : Debian 8.11 (jessie) 
bash GNU bash 4.3.30

-----
 Results, not in function:



-----
 Results, in function f1:
a test
an exported beer

Seen in man bash:
Quote:
-g create global variables when used in a shell function; otherwise
ignored
and noted with shellcheck:
Code:
...
In s1 line 21:
echo $my_test_a
     ^-- SC2031: my_test_a was modified in a subshell. That change might be lost. 
...

Apologies if I missed it ... cheers, drl

( currently listening: Bartok: String Quartets, but soon Yes )
This User Gave Thanks to drl For This Post:
sea
 

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LEARN ABOUT OSX

inline::wrapper::module

Inline::Wrapper::Module(3)				User Contributed Perl Documentation				Inline::Wrapper::Module(3)

NAME

       Inline::Wrapper::Module - Internal object wrapper for individual Inline modules.

SYNOPSIS

	use Inline::Wrapper::Module;

DESCRIPTION

       Inline::Wrapper::Module is used internally by Inline::Wrapper, and should not be used directly.	It will croak if you attempt to do so.

       It is a descendent class of Inline::Wrapper.

METHODS

   new()
       Takes the same arguments as "new()" in Inline::Wrapper, but also requires a module_name and lang_ext argument.

       Don't use this.	It will croak if you try to use it directly.

   initialize()
       Initialize the object instance.

   DESTROY()
       Destructor to clean up the object instance, and wipe the private code module namespace created when binding the symbol list.

INHERITANCE

       As Inline::Wrapper::Module is an inherited class from Inline::Wrapper, all methods that apply to the base class also apply to objects of
       this class.

       However, note that this has the following effects, due to the semantics of the load()/run() steps:

       auto_reload settings vs. when method effects take place:

	auto_reload value:  |  FALSE	      TRUE
	--------------------+------------------------------------------
	set_base_dir()	    |  no effect      after next reload / run()
	set_language()	    |  no effect      after next reload / run()
	add_language()	    |  no effect      after next reload / run()

       Please read through "load()" in Inline::Wrapper and "run()" in Inline::Wrapper for insight into why the implementation works like this.

SEE ALSO

       Inline::Wrapper

       The Inline documentation.

       The Inline-FAQ list.

       The examples/ directory of this module's distribution.

AUTHOR

       Please kindly read through this documentation and the examples/ thoroughly, before emailing me with questions.  Your answer is likely in
       here.

       Also make sure that your issue is actually with the Inline::Wrapper modules, and not with Inline itself.

       Jason McManus (INFIDEL) -- "infidel AT cpan.org"

LICENSE

       Copyright (c) Jason McManus

       This module may be used, modified, and distributed under the same terms as Perl itself.	Please see the license that came with your Perl
       distribution for details.

perl v5.16.2							    2010-03-10						Inline::Wrapper::Module(3)
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