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Programming-Idioms

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  • C

Idiom #205 Get an environment variable

Read an environment variable with the name "FOO" and assign it to the string variable foo. If it does not exist or if the system does not support environment variables, assign a value of "none".

#include <stdlib.h>
const char * foo = getenv("FOO");
if (foo == NULL) foo = "none";

Returns a pointer to the value or NULL
with Ada.Environment_Variables;
Foo : constant String :=
      Ada.Environment_Variables.Value (Name    => "FOO",
                                       Default => "none");

New implementation...
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tkoenig