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<pre><a name="line-1"></a><span class='hs-comment'>-- Copyright (C) 2003 David Roundy</span>
<a name="line-2"></a><span class='hs-comment'>--</span>
<a name="line-3"></a><span class='hs-comment'>-- This program is free software; you can redistribute it and/or modify</span>
<a name="line-4"></a><span class='hs-comment'>-- it under the terms of the GNU General Public License as published by</span>
<a name="line-5"></a><span class='hs-comment'>-- the Free Software Foundation; either version 2, or (at your option)</span>
<a name="line-6"></a><span class='hs-comment'>-- any later version.</span>
<a name="line-7"></a><span class='hs-comment'>--</span>
<a name="line-8"></a><span class='hs-comment'>-- This program is distributed in the hope that it will be useful,</span>
<a name="line-9"></a><span class='hs-comment'>-- but WITHOUT ANY WARRANTY; without even the implied warranty of</span>
<a name="line-10"></a><span class='hs-comment'>-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the</span>
<a name="line-11"></a><span class='hs-comment'>-- GNU General Public License for more details.</span>
<a name="line-12"></a><span class='hs-comment'>--</span>
<a name="line-13"></a><span class='hs-comment'>-- You should have received a copy of the GNU General Public License</span>
<a name="line-14"></a><span class='hs-comment'>-- along with this program; see the file COPYING. If not, write to</span>
<a name="line-15"></a><span class='hs-comment'>-- the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,</span>
<a name="line-16"></a><span class='hs-comment'>-- Boston, MA 02110-1301, USA.</span>
<a name="line-17"></a>
<a name="line-18"></a><span class='hs-comment'>{-# LANGUAGE CPP, ForeignFunctionInterface, DeriveDataTypeable #-}</span>
<a name="line-19"></a>
<a name="line-20"></a><span class='hs-comment'>-- |</span>
<a name="line-21"></a><span class='hs-comment'>-- Module : Exec</span>
<a name="line-22"></a><span class='hs-comment'>-- Copyright : 2003 David Roundy</span>
<a name="line-23"></a><span class='hs-comment'>-- License : GPL</span>
<a name="line-24"></a><span class='hs-comment'>-- Maintainer : darcs-devel@darcs.net</span>
<a name="line-25"></a><span class='hs-comment'>-- Stability : experimental</span>
<a name="line-26"></a><span class='hs-comment'>-- Portability : portable</span>
<a name="line-27"></a>
<a name="line-28"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Exec</span> <span class='hs-layout'>(</span>
<a name="line-29"></a> <span class='hs-varid'>exec</span>
<a name="line-30"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>execInteractive</span>
<a name="line-31"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>withoutNonBlock</span>
<a name="line-32"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>Redirects</span>
<a name="line-33"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>Redirect</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span>
<a name="line-34"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>ExecException</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span>
<a name="line-35"></a> <span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-36"></a>
<a name="line-37"></a><span class='hs-cpp'>#ifndef WIN32</span>
<a name="line-38"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Exception</span><span class='hs-varop'>.</span><span class='hs-conid'>Extensible</span> <span class='hs-layout'>(</span> <span class='hs-varid'>bracket</span> <span class='hs-layout'>)</span>
<a name="line-39"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>Posix</span><span class='hs-varop'>.</span><span class='hs-conid'>Env</span> <span class='hs-layout'>(</span> <span class='hs-varid'>setEnv</span><span class='hs-layout'>,</span> <span class='hs-varid'>getEnv</span><span class='hs-layout'>,</span> <span class='hs-varid'>unsetEnv</span> <span class='hs-layout'>)</span>
<a name="line-40"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>Posix</span><span class='hs-varop'>.</span><span class='hs-conid'>IO</span> <span class='hs-layout'>(</span> <span class='hs-varid'>queryFdOption</span><span class='hs-layout'>,</span> <span class='hs-varid'>setFdOption</span><span class='hs-layout'>,</span> <span class='hs-conid'>FdOption</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span> <span class='hs-varid'>stdInput</span> <span class='hs-layout'>)</span>
<a name="line-41"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>IO</span> <span class='hs-layout'>(</span> <span class='hs-varid'>stdin</span> <span class='hs-layout'>)</span>
<a name="line-42"></a><span class='hs-cpp'>#else</span>
<a name="line-43"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Exception</span><span class='hs-varop'>.</span><span class='hs-conid'>Extensible</span> <span class='hs-layout'>(</span> <span class='hs-varid'>catchJust</span><span class='hs-layout'>,</span> <span class='hs-conid'>IOException</span> <span class='hs-layout'>)</span>
<a name="line-44"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>List</span> <span class='hs-layout'>(</span> <span class='hs-varid'>isInfixOf</span> <span class='hs-layout'>)</span>
<a name="line-45"></a><span class='hs-cpp'>#endif</span>
<a name="line-46"></a>
<a name="line-47"></a><span class='hs-cpp'>#if __GLASGOW_HASKELL__ >= 612</span>
<a name="line-48"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>GHC</span><span class='hs-varop'>.</span><span class='hs-conid'>IO</span><span class='hs-varop'>.</span><span class='hs-conid'>Handle</span> <span class='hs-layout'>(</span> <span class='hs-varid'>hDuplicate</span> <span class='hs-layout'>)</span>
<a name="line-49"></a><span class='hs-cpp'>#else</span>
<a name="line-50"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>GHC</span><span class='hs-varop'>.</span><span class='hs-conid'>Handle</span> <span class='hs-layout'>(</span> <span class='hs-varid'>hDuplicate</span> <span class='hs-layout'>)</span>
<a name="line-51"></a><span class='hs-cpp'>#endif</span>
<a name="line-52"></a>
<a name="line-53"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Exception</span><span class='hs-varop'>.</span><span class='hs-conid'>Extensible</span> <span class='hs-layout'>(</span> <span class='hs-varid'>bracketOnError</span><span class='hs-layout'>,</span> <span class='hs-conid'>Exception</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span>
<a name="line-54"></a> <span class='hs-conid'>SomeException</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span> <span class='hs-layout'>)</span>
<a name="line-55"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Typeable</span> <span class='hs-layout'>(</span> <span class='hs-conid'>Typeable</span><span class='hs-layout'>,</span> <span class='hs-varid'>cast</span> <span class='hs-layout'>)</span>
<a name="line-56"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>Cmd</span> <span class='hs-layout'>(</span> <span class='hs-varid'>system</span> <span class='hs-layout'>)</span>
<a name="line-57"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>Exit</span> <span class='hs-layout'>(</span> <span class='hs-conid'>ExitCode</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span> <span class='hs-layout'>)</span>
<a name="line-58"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>IO</span> <span class='hs-layout'>(</span> <span class='hs-conid'>IOMode</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span> <span class='hs-varid'>openBinaryFile</span><span class='hs-layout'>,</span> <span class='hs-varid'>stdout</span> <span class='hs-layout'>)</span>
<a name="line-59"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>Process</span> <span class='hs-layout'>(</span> <span class='hs-varid'>runProcess</span><span class='hs-layout'>,</span> <span class='hs-varid'>terminateProcess</span><span class='hs-layout'>,</span> <span class='hs-varid'>waitForProcess</span> <span class='hs-layout'>)</span>
<a name="line-60"></a>
<a name="line-61"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Darcs</span><span class='hs-varop'>.</span><span class='hs-conid'>Global</span> <span class='hs-layout'>(</span> <span class='hs-varid'>whenDebugMode</span> <span class='hs-layout'>)</span>
<a name="line-62"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Progress</span> <span class='hs-layout'>(</span> <span class='hs-varid'>withoutProgress</span> <span class='hs-layout'>)</span>
<a name="line-63"></a>
<a name="line-64"></a><span class='hs-comment'>{-
<a name="line-65"></a> A redirection is a three-tuple of values (in, out, err).
<a name="line-66"></a> The most common values are:
<a name="line-67"></a>
<a name="line-68"></a> AsIs don't change it
<a name="line-69"></a> Null /dev/null on Unix, NUL on Windows
<a name="line-70"></a> File open a file for reading or writing
<a name="line-71"></a>
<a name="line-72"></a> There is also the value Stdout, which is only meaningful for
<a name="line-73"></a> redirection of errors, and is performed AFTER stdout is
<a name="line-74"></a> redirected so that output and errors mix together. StdIn and
<a name="line-75"></a> StdErr could be added as well if they are useful.
<a name="line-76"></a>
<a name="line-77"></a> NOTE: Lots of care must be taken when redirecting stdin, stdout
<a name="line-78"></a> and stderr to one of EACH OTHER, since the ORDER in which they
<a name="line-79"></a> are changed have a significant effect on the result.
<a name="line-80"></a>-}</span>
<a name="line-81"></a>
<a name="line-82"></a><a name="Redirects"></a><span class='hs-keyword'>type</span> <span class='hs-conid'>Redirects</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-conid'>Redirect</span><span class='hs-layout'>,</span> <span class='hs-conid'>Redirect</span><span class='hs-layout'>,</span> <span class='hs-conid'>Redirect</span><span class='hs-layout'>)</span>
<a name="line-83"></a>
<a name="line-84"></a><a name="Redirect"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>Redirect</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>AsIs</span>
<a name="line-85"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Null</span>
<a name="line-86"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>File</span> <span class='hs-conid'>FilePath</span>
<a name="line-87"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Stdout</span>
<a name="line-88"></a> <span class='hs-keyword'>deriving</span> <span class='hs-conid'>Show</span>
<a name="line-89"></a>
<a name="line-90"></a><a name="ExecException"></a><span class='hs-comment'>{-
<a name="line-91"></a> ExecException is thrown by exec if any system call fails,
<a name="line-92"></a> for example because the executable we're trying to run
<a name="line-93"></a> doesn't exist.
<a name="line-94"></a>-}</span>
<a name="line-95"></a><a name="ExecException"></a><span class='hs-comment'>-- ExecException cmd args redirecs errorDesc</span>
<a name="line-96"></a><a name="ExecException"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>ExecException</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>ExecException</span>
<a name="line-97"></a> <span class='hs-conid'>String</span> <span class='hs-comment'>-- cmd</span>
<a name="line-98"></a> <span class='hs-keyglyph'>[</span><span class='hs-conid'>String</span><span class='hs-keyglyph'>]</span> <span class='hs-comment'>-- args</span>
<a name="line-99"></a> <span class='hs-conid'>Redirects</span> <span class='hs-comment'>-- redirects</span>
<a name="line-100"></a> <span class='hs-conid'>String</span> <span class='hs-comment'>-- errorDesc</span>
<a name="line-101"></a> <span class='hs-keyword'>deriving</span> <span class='hs-layout'>(</span><span class='hs-conid'>Typeable</span><span class='hs-layout'>,</span><span class='hs-conid'>Show</span><span class='hs-layout'>)</span>
<a name="line-102"></a>
<a name="line-103"></a><a name="instance%20Exception%20ExecException"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>Exception</span> <span class='hs-conid'>ExecException</span> <span class='hs-keyword'>where</span>
<a name="line-104"></a> <span class='hs-varid'>toException</span> <span class='hs-varid'>e</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>SomeException</span> <span class='hs-varid'>e</span>
<a name="line-105"></a> <span class='hs-varid'>fromException</span> <span class='hs-layout'>(</span><span class='hs-conid'>SomeException</span> <span class='hs-varid'>e</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>cast</span> <span class='hs-varid'>e</span>
<a name="line-106"></a>
<a name="line-107"></a><span class='hs-sel'>_devNull</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>FilePath</span>
<a name="line-108"></a><span class='hs-cpp'>#ifdef WIN32</span>
<a name="line-109"></a><span class='hs-sel'>_devNull</span> <span class='hs-keyglyph'>=</span> <span class='hs-str'>"NUL"</span>
<a name="line-110"></a><span class='hs-cpp'>#else</span>
<a name="line-111"></a><span class='hs-sel'>_devNull</span> <span class='hs-keyglyph'>=</span> <span class='hs-str'>"/dev/null"</span>
<a name="line-112"></a><span class='hs-cpp'>#endif</span>
<a name="line-113"></a>
<a name="line-114"></a><a name="exec"></a><span class='hs-comment'>{-
<a name="line-115"></a> We use System.Process, which does the necessary quoting
<a name="line-116"></a> and redirection for us behind the scenes.
<a name="line-117"></a>-}</span>
<a name="line-118"></a><span class='hs-definition'>exec</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>String</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Redirects</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>ExitCode</span>
<a name="line-119"></a><span class='hs-definition'>exec</span> <span class='hs-varid'>cmd</span> <span class='hs-varid'>args</span> <span class='hs-layout'>(</span><span class='hs-varid'>inp</span><span class='hs-layout'>,</span><span class='hs-varid'>out</span><span class='hs-layout'>,</span><span class='hs-varid'>err</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>withoutProgress</span> <span class='hs-varop'>$</span> <span class='hs-keyword'>do</span>
<a name="line-120"></a> <span class='hs-varid'>h_stdin</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>redirect</span> <span class='hs-varid'>inp</span> <span class='hs-conid'>ReadMode</span>
<a name="line-121"></a> <span class='hs-varid'>h_stdout</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>redirect</span> <span class='hs-varid'>out</span> <span class='hs-conid'>WriteMode</span>
<a name="line-122"></a> <span class='hs-varid'>h_stderr</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>redirect</span> <span class='hs-varid'>err</span> <span class='hs-conid'>WriteMode</span>
<a name="line-123"></a> <span class='hs-varid'>withExit127</span> <span class='hs-varop'>$</span> <span class='hs-varid'>bracketOnError</span>
<a name="line-124"></a> <span class='hs-layout'>(</span><span class='hs-keyword'>do</span> <span class='hs-varid'>doOptionalDebug</span>
<a name="line-125"></a> <span class='hs-varid'>runProcess</span> <span class='hs-varid'>cmd</span> <span class='hs-varid'>args</span> <span class='hs-conid'>Nothing</span> <span class='hs-conid'>Nothing</span> <span class='hs-varid'>h_stdin</span> <span class='hs-varid'>h_stdout</span> <span class='hs-varid'>h_stderr</span><span class='hs-layout'>)</span>
<a name="line-126"></a> <span class='hs-layout'>(</span><span class='hs-varid'>terminateProcess</span><span class='hs-layout'>)</span>
<a name="line-127"></a> <span class='hs-layout'>(</span><span class='hs-varid'>waitForProcess</span><span class='hs-layout'>)</span>
<a name="line-128"></a> <span class='hs-keyword'>where</span>
<a name="line-129"></a> <span class='hs-varid'>doOptionalDebug</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>whenDebugMode</span> <span class='hs-varop'>.</span> <span class='hs-varid'>putStrLn</span> <span class='hs-varop'>.</span> <span class='hs-varid'>unwords</span> <span class='hs-varop'>$</span>
<a name="line-130"></a> <span class='hs-varid'>cmd</span> <span class='hs-conop'>:</span> <span class='hs-varid'>args</span> <span class='hs-varop'>++</span> <span class='hs-keyglyph'>[</span><span class='hs-str'>"; #"</span><span class='hs-keyglyph'>]</span> <span class='hs-varop'>++</span> <span class='hs-varid'>map</span> <span class='hs-varid'>show</span> <span class='hs-keyglyph'>[</span><span class='hs-varid'>inp</span><span class='hs-layout'>,</span> <span class='hs-varid'>out</span><span class='hs-layout'>,</span> <span class='hs-varid'>err</span><span class='hs-keyglyph'>]</span>
<a name="line-131"></a> <span class='hs-varid'>redirect</span> <span class='hs-conid'>AsIs</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-conid'>Nothing</span>
<a name="line-132"></a> <span class='hs-varid'>redirect</span> <span class='hs-conid'>Null</span> <span class='hs-varid'>mode</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>`fmap`</span> <span class='hs-varid'>openBinaryFile</span> <span class='hs-sel'>_devNull</span> <span class='hs-varid'>mode</span>
<a name="line-133"></a> <span class='hs-varid'>redirect</span> <span class='hs-layout'>(</span><span class='hs-conid'>File</span> <span class='hs-str'>"/dev/null"</span><span class='hs-layout'>)</span> <span class='hs-varid'>mode</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>redirect</span> <span class='hs-conid'>Null</span> <span class='hs-varid'>mode</span>
<a name="line-134"></a> <span class='hs-varid'>redirect</span> <span class='hs-layout'>(</span><span class='hs-conid'>File</span> <span class='hs-varid'>f</span><span class='hs-layout'>)</span> <span class='hs-varid'>mode</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>`fmap`</span> <span class='hs-varid'>openBinaryFile</span> <span class='hs-varid'>f</span> <span class='hs-varid'>mode</span>
<a name="line-135"></a> <span class='hs-comment'>-- hDuplicate stdout rather than passing stdout itself,</span>
<a name="line-136"></a> <span class='hs-comment'>-- because runProcess closes the Handles we pass it.</span>
<a name="line-137"></a> <span class='hs-varid'>redirect</span> <span class='hs-conid'>Stdout</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>`fmap`</span> <span class='hs-varid'>hDuplicate</span> <span class='hs-varid'>stdout</span>
<a name="line-138"></a>
<a name="line-139"></a><a name="execInteractive"></a><span class='hs-definition'>execInteractive</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>ExitCode</span>
<a name="line-140"></a><span class='hs-cpp'>#ifndef WIN32</span>
<a name="line-141"></a><span class='hs-comment'>{-
<a name="line-142"></a>This should handle arbitrary commands interpreted by the shell on Unix since
<a name="line-143"></a>that's what people expect. But we don't want to allow the shell to interpret
<a name="line-144"></a>the argument in any way, so we set an environment variable and call
<a name="line-145"></a>cmd "$DARCS_ARGUMENT"
<a name="line-146"></a>-}</span>
<a name="line-147"></a><span class='hs-definition'>execInteractive</span> <span class='hs-varid'>cmd</span> <span class='hs-varid'>arg</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>withoutProgress</span> <span class='hs-varop'>$</span> <span class='hs-keyword'>do</span>
<a name="line-148"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>var</span> <span class='hs-keyglyph'>=</span> <span class='hs-str'>"DARCS_ARGUMENT"</span>
<a name="line-149"></a> <span class='hs-varid'>stdin</span> <span class='hs-varop'>`seq`</span> <span class='hs-varid'>return</span> <span class='hs-conid'>()</span>
<a name="line-150"></a> <span class='hs-varid'>withoutNonBlock</span> <span class='hs-varop'>$</span> <span class='hs-varid'>bracket</span>
<a name="line-151"></a> <span class='hs-layout'>(</span><span class='hs-keyword'>do</span> <span class='hs-varid'>oldval</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>getEnv</span> <span class='hs-varid'>var</span>
<a name="line-152"></a> <span class='hs-varid'>setEnv</span> <span class='hs-varid'>var</span> <span class='hs-varid'>arg</span> <span class='hs-conid'>True</span>
<a name="line-153"></a> <span class='hs-varid'>return</span> <span class='hs-varid'>oldval</span><span class='hs-layout'>)</span>
<a name="line-154"></a> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>oldval</span> <span class='hs-keyglyph'>-></span>
<a name="line-155"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>oldval</span> <span class='hs-keyword'>of</span>
<a name="line-156"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>unsetEnv</span> <span class='hs-varid'>var</span>
<a name="line-157"></a> <span class='hs-conid'>Just</span> <span class='hs-varid'>val</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>setEnv</span> <span class='hs-varid'>var</span> <span class='hs-varid'>val</span> <span class='hs-conid'>True</span><span class='hs-layout'>)</span>
<a name="line-158"></a> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>withExit127</span> <span class='hs-varop'>$</span> <span class='hs-varid'>system</span> <span class='hs-varop'>$</span> <span class='hs-varid'>cmd</span><span class='hs-varop'>++</span><span class='hs-str'>" \"$"</span><span class='hs-varop'>++</span><span class='hs-varid'>var</span><span class='hs-varop'>++</span><span class='hs-str'>"\""</span><span class='hs-layout'>)</span>
<a name="line-159"></a>
<a name="line-160"></a><span class='hs-cpp'>#else</span>
<a name="line-161"></a><span class='hs-comment'>-- The `system' function passes commands to execute via cmd.exe (or</span>
<a name="line-162"></a><span class='hs-comment'>-- command.com) it's return value is equivalent to the one returned by the</span>
<a name="line-163"></a><span class='hs-comment'>-- shell. For regular applications - this works correctly resulting in the</span>
<a name="line-164"></a><span class='hs-comment'>-- exit code of the program. However in case of a command/file which can't be</span>
<a name="line-165"></a><span class='hs-comment'>-- found - cmd.exe will return 1 instead of propagating the ExitFailure 9009</span>
<a name="line-166"></a><span class='hs-comment'>-- which on windows is equivalent to ExitFailure 127 from *nix machines.</span>
<a name="line-167"></a><span class='hs-comment'>--</span>
<a name="line-168"></a><span class='hs-comment'>-- Here we force return the exit code of the last cmd.exe action by appending</span>
<a name="line-169"></a><span class='hs-comment'>-- & exit !errorlevel! to the command being executed that way chaining with</span>
<a name="line-170"></a><span class='hs-comment'>-- ortryrunning works correctly.</span>
<a name="line-171"></a><span class='hs-comment'>--</span>
<a name="line-172"></a><span class='hs-comment'>-- SETLOCAL EnableDelayedExpansion makes sure that !variable! expansion is done</span>
<a name="line-173"></a><span class='hs-comment'>-- correctly on systems where that function is not enabled by default.</span>
<a name="line-174"></a><span class='hs-comment'>--</span>
<a name="line-175"></a><span class='hs-definition'>execInteractive</span> <span class='hs-varid'>cmd</span> <span class='hs-varid'>arg</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>withoutProgress</span> <span class='hs-varop'>$</span> <span class='hs-keyword'>do</span>
<a name="line-176"></a> <span class='hs-varid'>withExit127</span> <span class='hs-varop'>$</span> <span class='hs-varid'>system</span> <span class='hs-varop'>$</span> <span class='hs-str'>"SETLOCAL EnableDelayedExpansion & "</span> <span class='hs-varop'>++</span>
<a name="line-177"></a> <span class='hs-varid'>cmd</span> <span class='hs-varop'>++</span> <span class='hs-str'>" "</span> <span class='hs-varop'>++</span> <span class='hs-varid'>arg</span> <span class='hs-varop'>++</span>
<a name="line-178"></a> <span class='hs-str'>" & exit !errorlevel!"</span>
<a name="line-179"></a><span class='hs-cpp'>#endif</span>
<a name="line-180"></a>
<a name="line-181"></a><a name="withoutNonBlock"></a><span class='hs-definition'>withoutNonBlock</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>IO</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-varid'>a</span>
<a name="line-182"></a><span class='hs-cpp'>#ifndef WIN32</span>
<a name="line-183"></a><span class='hs-comment'>{-
<a name="line-184"></a>Do IO without NonBlockingRead on stdInput.
<a name="line-185"></a>
<a name="line-186"></a>This is needed when running unsuspecting external commands with interactive
<a name="line-187"></a>mode - if read from terminal is non-blocking also write to terminal is
<a name="line-188"></a>non-blocking.
<a name="line-189"></a>-}</span>
<a name="line-190"></a><span class='hs-definition'>withoutNonBlock</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span>
<a name="line-191"></a> <span class='hs-keyword'>do</span> <span class='hs-varid'>nb</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>queryFdOption</span> <span class='hs-varid'>stdInput</span> <span class='hs-conid'>NonBlockingRead</span>
<a name="line-192"></a> <span class='hs-keyword'>if</span> <span class='hs-varid'>nb</span>
<a name="line-193"></a> <span class='hs-keyword'>then</span> <span class='hs-varid'>bracket</span>
<a name="line-194"></a> <span class='hs-layout'>(</span><span class='hs-varid'>setFdOption</span> <span class='hs-varid'>stdInput</span> <span class='hs-conid'>NonBlockingRead</span> <span class='hs-conid'>False</span><span class='hs-layout'>)</span>
<a name="line-195"></a> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>setFdOption</span> <span class='hs-varid'>stdInput</span> <span class='hs-conid'>NonBlockingRead</span> <span class='hs-conid'>True</span><span class='hs-layout'>)</span>
<a name="line-196"></a> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span>
<a name="line-197"></a> <span class='hs-keyword'>else</span> <span class='hs-varid'>x</span>
<a name="line-198"></a><span class='hs-cpp'>#else</span>
<a name="line-199"></a><span class='hs-definition'>withoutNonBlock</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-varid'>x</span>
<a name="line-200"></a><span class='hs-cpp'>#endif</span>
<a name="line-201"></a>
<a name="line-202"></a><a name="withExit127"></a><span class='hs-comment'>{-
<a name="line-203"></a>Ensure that we exit 127 if the thing we are trying to run does not exist
<a name="line-204"></a>(Only needed under Windows)
<a name="line-205"></a>-}</span>
<a name="line-206"></a><span class='hs-definition'>withExit127</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>IO</span> <span class='hs-conid'>ExitCode</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>ExitCode</span>
<a name="line-207"></a><span class='hs-cpp'>#ifdef WIN32</span>
<a name="line-208"></a><span class='hs-definition'>withExit127</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>catchJust</span> <span class='hs-varid'>notFoundError</span> <span class='hs-varid'>a</span> <span class='hs-layout'>(</span><span class='hs-varid'>const</span> <span class='hs-varop'>$</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>ExitFailure</span> <span class='hs-num'>127</span><span class='hs-layout'>)</span>
<a name="line-209"></a>
<a name="line-210"></a><a name="notFoundError"></a><span class='hs-definition'>notFoundError</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>IOException</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Maybe</span> <span class='hs-conid'>()</span>
<a name="line-211"></a><span class='hs-definition'>notFoundError</span> <span class='hs-varid'>e</span> <span class='hs-keyglyph'>|</span> <span class='hs-str'>"runProcess: does not exist"</span> <span class='hs-varop'>`isInfixOf`</span> <span class='hs-varid'>show</span> <span class='hs-varid'>e</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-conid'>()</span>
<a name="line-212"></a><span class='hs-definition'>notFoundError</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span>
<a name="line-213"></a><span class='hs-cpp'>#else</span>
<a name="line-214"></a><span class='hs-definition'>withExit127</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>id</span>
<a name="line-215"></a><span class='hs-cpp'>#endif</span>
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