C Library Functions - system_getenv (3)

NAME

system_getenv(3f) - [M_system:ENVIRONMENT] get environment variable from Fortran by calling get_environment_variable(3f) (LICENSE:PD)

Synopsis
Description
Options
Example
Author
License

SYNOPSIS

function system_getenv(name,default)

    character(len=:),allocatable         :: system_getenv
    character(len=*),intent(in)          :: name
    character(len=*),intent(in),optional :: default

DESCRIPTION

The system_getenv() function gets the value of an environment variable.

OPTIONS

name Return the value of the specified environment variable or blank if the variable is not defined.

default
If the value returned would be blank this value will be used instead.

EXAMPLE

Sample setting an environment variable from Fortran:

   program demo_system_getenv
   use M_system, only : system_getenv
   use M_system, only : ge=>system_getenv
   implicit none
   character(len=:),allocatable :: TMPDIR

      write(*,’("USER     : ",a)’)system_getenv(’USER’)
      write(*,’("LOGNAME  : ",a)’)system_getenv(’LOGNAME’)
      write(*,’("USERNAME : ",a)’)system_getenv(’USERNAME’)

      ! look first for USER then LOGNAME then USERNAME
      write(*, *)ge(’USER’, ge(’LOGNAME’, ge(’USERNAME’, ’UNKNOWN’)))

      TMPDIR= ge(’TMPDIR’, ge(’TMP’, ge(’TEMPDIR’, ge(’TEMP’, ’/tmp’))))
      write(*,*)’favorite scratch area is ’,TMPDIR

   end program demo_system_getenv

AUTHOR

John S. Urban

LICENSE

Public Domain

Nemo Release 3.1

system_getenv (3)

July 22, 2023

Generated by manServer 1.08 from 09ad06b4-ac8e-4997-87e6-cfab5b09ff22 using man macros.

name	Return the value of the specified environment variable or blank if the variable is not defined.
default
	If the value returned would be blank this value will be used instead.