C Library Functions - set_environment_variable (3)

NAME

set_environment_variable(3f) - [M_system:ENVIRONMENT] call setenv(3c) to set environment variable (LICENSE:PD)

Synopsis
Description
Options
Examples
Author
License

SYNOPSIS

subroutine set_environment_variable(NAME, VALUE, STATUS)

     character(len=*)               :: NAME
     character(len=*)               :: VALUE
     integer, optional, intent(out) :: STATUS

DESCRIPTION

The set_environment_variable() procedure adds or changes the value of environment variables.

OPTIONS

NAME If name does not already exist in the environment, then string is added to the environment. If name does exist, then the value of name in the environment is changed to value.

VALUE Value to assign to environment variable NAME

STATUS returns zero on success, or nonzero if an error occurs. A non-zero error usually indicates sufficient memory does not exist to store the variable.

EXAMPLES

Sample setting an environment variable from Fortran:

   program demo_set_environment_variable
   use M_system, only : set_environment_variable
   use iso_c_binding
   implicit none
   integer :: ierr
      !x!
      write(*,’(a)’)’no environment variables containing "GRU":’
      call execute_command_line(’env|grep GRU’)
      !x!
      call set_environment_variable(’GRU’,’this is the value’,ierr)
      write(*,’(a,i0)’)’now "GRU" should be defined, status=’,ierr
      call execute_command_line(’env|grep GRU’)
      !x!
      call set_environment_variable(’GRU2’,’this is the second value’,ierr)
      write(*,’(a,i0)’)’now "GRU" and "GRU2" should be defined, status =’,ierr
      !x!
      call execute_command_line(’env|grep GRU’)
   end program demo_set_environment_variable

Results:

   no environment variables containing "GRU":
   now "GRU" should be defined, status=0
   GRU=this is the value
   now "GRU" and "GRU2" should be defined, status =0
   GRU2=this is the second value
   GRU=this is the value

AUTHOR

John S. Urban

LICENSE

Public Domain

Nemo Release 3.1

set_environment_variable (3)

June 29, 2025

Generated by manServer 1.08 from ad6efca9-3874-4ca4-896a-a777841c3e8c using man macros.

NAME	If name does not already exist in the environment, then string is added to the environment. If name does exist, then the value of name in the environment is changed to value.
VALUE	Value to assign to environment variable NAME
STATUS	returns zero on success, or nonzero if an error occurs. A non-zero error usually indicates sufficient memory does not exist to store the variable.