SQL: set environment variable

setenvvar.sql

-- Set environment variable from a string value 
-- you need library QSYSINC installed:
-- https://www.ibm.com/support/knowledgecenter/ssw_ibm_i_74/apiref/conQSYSINC.htm
--
-- Simply paste this gist into ACS SQL and step through the example.
--
-- It is a cool example how far you can go with SQL: Have fun - 
-- (C) Niels Liisberg 2023
--
-- This gist is distributed on an "as is" basis, without warranties 
-- or conditions of any kind, either express or implied.
----------------------------------------------------------------------------------------------
call qsys2.ifs_write(
    path_name => '/tmp/main.c' , 
    file_ccsid => 1208, 
    overwrite => 'REPLACE',
    line =>'
{
    #include <stdlib.h>
    char env [32000];
    
    SETENVVAR.ENVIRONMENT_VARIABLE.DAT[SETENVVAR.ENVIRONMENT_VARIABLE.LEN] =0;
    SETENVVAR.ENVIRONMENT_VALUE.DAT[SETENVVAR.ENVIRONMENT_VALUE.LEN] =0;
    strcpy ( env, SETENVVAR.ENVIRONMENT_VARIABLE.DAT);
    strcat ( env , "="); 
    strcat ( env , SETENVVAR.ENVIRONMENT_VALUE.DAT);
    putenv ( env) ;
    
} 
');


create or replace procedure qusrsys.setenvvar (
    environment_variable  varchar(256),
    environment_value     varchar(32000)
) 
external action 
modifies sql data 
deterministic
set option output=*print, commit=*none, dbgview = *source --list
main:
begin
    include '/tmp/main.c';
end;

-- Usecase
call qusrsys.setenvvar ('MYENVVAR' , 'Some text'); 
 
-- using my other GETENV to look at the result 
values (
    qusrsys.envvar ('MYENVVAR')
);