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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
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:
 
Test Your Knowledge in Computers #22
Difficulty: Easy
RAM is considered volatile memory in a computer system.
True or False?

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Alzabo::Runtime::InsertHandle(3pm)			User Contributed Perl Documentation			Alzabo::Runtime::InsertHandle(3pm)

NAME
Alzabo::Runtime::InsertHandle - A handle representing an insert SYNOPSIS
my $handle = $table->insert_handle ( columns => [ $table->columns( 'name', 'job' ) ] ); my $faye_row = $handle->insert( values => { name => 'Faye', job => 'HK Pop Chanteuse' } ); my $guesch_row = $handle->insert( values => { name => 'Guesch', job => 'French Chanteuse and Dancer' } ); DESCRIPTION
This object is analogous to a DBI statement handle, and can be used to insert multiple rows into a table more efficiently than repeatedly calling "Alzabo::Runtime::Table->insert()". METHODS
Objects of this class provide one public method: insert This method is used to insert a new row into a table. It accepts the following parameters: * values This should be a hash reference containing the values to be inserted into the table. If no value is given for a primary key column and the column is "sequenced" then the primary key will be auto-generated. If values are not provided for other columns which were given when "Alzabo::Runtime::Table->insert_handle" was called, this method first checks to see if a value was provided for the column when "Alzabo::Runtime::Table->insert_handle" was called. If none was pro- vided, then the column's default value is used. If column values were passed to "Alzabo::Runtime::Table->insert_handle", then these can be overridden by values passed to this method. It is not possible to override column values that were given as SQL functions when "Alzabo::Runtime::Table->insert_handle" was called. This method returns a new "Alzabo::Runtime::Row" object. Throws: "Alzabo::Exception::Logic", "Alzabo::Exception::Params" perl v5.8.8 2007-12-23 Alzabo::Runtime::InsertHandle(3pm)

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