GETENVQQ

 

Portability Function: Returns the value of an environment variable.

Module

USE IFPORT

Syntax

result = GETENVQQ (varname,value)

varname

(Input) Character*(*). Name of environment variable.

value

(Output) Character*(*). Value of the specified environment variable, in uppercase.

Results

The result type is INTEGER(4). The result is the length of the string returned in value. Zero is returned if the given variable is not defined.

GETENVQQ searches the list of environment variables for an entry corresponding to varname. Environment variables define the environment in which a process executes. For example, the LIB environment variable defines the default search path for libraries to be linked with a program.

Note that some environment variables may exist only on a per-process basis and may not be present at the command-line level.

GETENVQQ uses the C runtime routine getenv and SETENVQQ uses the C runtime routine _putenv. From the C documentation:

getenv and _putenv use the copy of the environment pointed to by the global variable _environ to access the environment. getenv operates only on the data structures accessible to the run-time library and not on the environment segment created for the process by the operating system.

In a program that uses the main function, _environ is initialized at program startup to settings taken from the operating system's environment.

Changes made outside the program by the console SET command, for example, SET MY_VAR=ABCDE, will be reflected by GETENVQQ.

GETENVQQ and SETENVQQ will not work properly with the Windows* APIs GetEnvironmentVariable and SetEnvironmentVariable.

Compatibility

CONSOLE STANDARD GRAPHICS QUICKWIN GRAPHICS DLL LIB

Example

! Program to demonstrate GETENVQQ and SETENVQQ

USE IFPORT

USE IFCORE

INTEGER(4) lenv, lval

CHARACTER(80) env, val, enval

 

WRITE (*,900) ' Enter environment variable name to create, &

modify, or delete: '

lenv = GETSTRQQ(env)

IF (lenv .EQ. 0) STOP

WRITE (*,900) ' Value of variable (ENTER to delete): '

lval = GETSTRQQ(val)

IF (lval .EQ. 0) val = ' '

enval = env(1:lenv) // '=' // val(1:lval)

IF (SETENVQQ(enval)) THEN

lval = GETENVQQ(env(1:lenv), val)

IF (lval .EQ. 0) THEN

WRITE (*,*) 'Can''t get environment variable'

ELSE IF (lval .GT. LEN(val)) THEN

WRITE (*,*) 'Buffer too small'

ELSE

WRITE (*,*) env(:lenv), ': ', val(:lval)

WRITE (*,*) 'Length: ', lval

END IF

ELSE

WRITE (*,*) 'Can''t set environment variable'

END IF

900 FORMAT (A, \)

END

See Also