mirror of
https://github.com/Mercury-Language/mercury.git
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9e82965527
library/io.m:
Use setenv() and _wputenv_s() to set environment variables
on C backends. Unlike putenv() and _wputenv(), these can be
relied upon to copy their inputs, so the inputs can safely
be garbage collected after the call returns.
tests/hard_coded/Mmakefile:
tests/hard_coded/setenv.{m,exp}:
Test case. Only run in grades for which io.set_environment_var/4
succeeds.
45 lines
1020 B
Mathematica
45 lines
1020 B
Mathematica
:- module setenv.
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:- interface.
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:- import_module io.
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:- pred main(io::di, io::uo) is det.
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:- implementation.
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:- import_module gc.
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:- import_module int.
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:- import_module list.
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:- import_module maybe.
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:- import_module string.
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main(!IO) :-
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io.set_environment_var("foo", "bar", !IO),
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% Earlier versions of the Mercury library relied on putenv, which
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% on many platforms requires that we don't garbage collect the
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% string we pass it. This code tests we can handle that.
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use_mem(1000000, !IO),
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gc.garbage_collect(!IO),
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use_mem(1000000, !IO),
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io.get_environment_var("foo", Res, !IO),
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(
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Res = yes(Value),
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io.write_string("Got value: " ++ Value ++ "\n", !IO)
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;
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Res = no,
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io.write_string("Failure!\n", !IO)
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).
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:- pred use_mem(int::in, io::di, io::uo) is det.
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use_mem(N, !IO) :-
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io.write_string("Use mem: ", !IO),
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( if length(1 `..` N) = N then
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io.write_string("ok\n", !IO)
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else
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io.write_string("hmm\n", !IO)
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).
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