Sophie: ghc-MissingH-devel-1.1.0.3-2.fc14 i686

ghc-MissingH-devel-1.1.0.3-2.fc14.i686.rpm

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>System.Cmd.Utils</TITLE
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>MissingH-1.1.0.3: Large utility library</TD
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><A HREF="src/System-Cmd-Utils.html"
>Source code</A
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><FONT SIZE="6"
>System.Cmd.Utils</FONT
></TD
><TD ALIGN="right"
><TABLE CLASS="narrow" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="infohead"
>Portability</TD
><TD CLASS="infoval"
>portable to platforms with POSIX process\/signal tools</TD
></TR
><TR
><TD CLASS="infohead"
>Stability</TD
><TD CLASS="infoval"
>provisional</TD
></TR
><TR
><TD CLASS="infohead"
>Maintainer</TD
><TD CLASS="infoval"
>John Goerzen &lt;jgoerzen@complete.org&gt;</TD
></TR
></TABLE
></TD
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></TABLE
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><TD CLASS="section4"
><B
>Contents</B
></TD
></TR
><TR
><TD
><DL
><DT
><A HREF="#1"
>High-Level Tools
</A
></DT
><DD
><DL
><DT
><A HREF="#2"
>Piping with lazy strings
</A
></DT
><DT
><A HREF="#3"
>Piping with handles
</A
></DT
></DL
></DD
><DT
><A HREF="#4"
>Low-Level Tools
</A
></DT
></DL
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section1"
>Description</TD
></TR
><TR
><TD CLASS="doc"
><P
>Command invocation utilities.
</P
><P
>Written by John Goerzen, jgoerzen@complete.org
</P
><P
>Please note: Most of this module is not compatible with Hugs.
</P
><P
>Command lines executed will be logged using <A HREF="System-Log-Logger.html"
>System.Log.Logger</A
> at the
DEBUG level.  Failure messages will be logged at the WARNING level in addition
to being raised as an exception.  Both are logged under
&quot;System.Cmd.Utils.funcname&quot; -- for instance,
&quot;System.Cmd.Utils.safeSystem&quot;.  If you wish to suppress these messages
globally, you can simply run:
</P
><PRE
> updateGlobalLogger &quot;System.Cmd.Utils.safeSystem&quot;
                     (setLevel CRITICAL)
</PRE
><P
>See also: <TT
><A HREF="/usr/share/doc/ghc/html/libraries/hslogger-1.1.0/System-Log-Logger.html#v%3AupdateGlobalLogger"
>updateGlobalLogger</A
></TT
>,
<A HREF="System-Log-Logger.html"
>System.Log.Logger</A
>.
</P
><P
>It is possible to set up pipelines with these utilities.  Example:
</P
><PRE
> (pid1, x1) &lt;- pipeFrom &quot;ls&quot; [&quot;/etc&quot;]
 (pid2, x2) &lt;- pipeBoth &quot;grep&quot; [&quot;x&quot;] x1
 putStr x2
 ... the grep output is displayed ...
 forceSuccess pid2
 forceSuccess pid1
</PRE
><P
>Remember, when you use the functions that return a String, you must not call
<TT
><A HREF="System-Cmd-Utils.html#v%3AforceSuccess"
>forceSuccess</A
></TT
> until after all data from the String has been consumed.  Failure
to wait will cause your program to appear to hang.
</P
><P
>Here is an example of the wrong way to do it:
</P
><PRE
> (pid, x) &lt;- pipeFrom &quot;ls&quot; [&quot;/etc&quot;]
 forceSuccess pid         -- Hangs; the called program hasn't terminated yet
 processTheData x
</PRE
><P
>You must instead process the data before calling <TT
><A HREF="System-Cmd-Utils.html#v%3AforceSuccess"
>forceSuccess</A
></TT
>.
</P
><P
>When using the hPipe family of functions, this is probably more obvious.
</P
><P
>Most of this module will be incompatible with Windows.
</P
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section1"
>Synopsis</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="body"
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="decl"
><SPAN CLASS="keyword"
>data</SPAN
>  <A HREF="#t%3APipeHandle"
>PipeHandle</A
>  = <A HREF="#v%3APipeHandle"
>PipeHandle</A
> {<TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="recfield"
><A HREF="#v%3AprocessID"
>processID</A
> :: <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-Posix-Types.html#t%3AProcessID"
>ProcessID</A
></TD
></TR
><TR
><TD CLASS="recfield"
><A HREF="#v%3AphCommand"
>phCommand</A
> :: <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
></TD
></TR
><TR
><TD CLASS="recfield"
><A HREF="#v%3AphArgs"
>phArgs</A
> :: [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>]</TD
></TR
><TR
><TD CLASS="recfield"
><A HREF="#v%3AphCreator"
>phCreator</A
> :: <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
></TD
></TR
></TABLE
>}</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AsafeSystem"
>safeSystem</A
> :: <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> <A HREF="/usr/share/doc/ghc/html/libraries/ghc-prim-0.2.0.0/GHC-Unit.html#t%3A%28%29"
>()</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AforceSuccess"
>forceSuccess</A
> :: <A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
> -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> <A HREF="/usr/share/doc/ghc/html/libraries/ghc-prim-0.2.0.0/GHC-Unit.html#t%3A%28%29"
>()</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AposixRawSystem"
>posixRawSystem</A
> :: <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> <A HREF="/usr/share/doc/ghc/html/libraries/unix-2.4.0.2/System-Posix-Process-Internals.html#t%3AProcessStatus"
>ProcessStatus</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AforkRawSystem"
>forkRawSystem</A
> :: <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-Posix-Types.html#t%3AProcessID"
>ProcessID</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3ApipeFrom"
>pipeFrom</A
> :: <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> (<A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
>, <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>)</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3ApipeLinesFrom"
>pipeLinesFrom</A
> :: <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> (<A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
>, [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>])</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3ApipeTo"
>pipeTo</A
> :: <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
> -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> <A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3ApipeBoth"
>pipeBoth</A
> :: <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
> -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> (<A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
>, <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>)</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AhPipeFrom"
>hPipeFrom</A
> :: <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> (<A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
>, <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/GHC-IO-Handle.html#t%3AHandle"
>Handle</A
>)</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AhPipeTo"
>hPipeTo</A
> :: <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> (<A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
>, <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/GHC-IO-Handle.html#t%3AHandle"
>Handle</A
>)</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AhPipeBoth"
>hPipeBoth</A
> :: <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> (<A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
>, <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/GHC-IO-Handle.html#t%3AHandle"
>Handle</A
>, <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/GHC-IO-Handle.html#t%3AHandle"
>Handle</A
>)</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="decl"
><SPAN CLASS="keyword"
>data</SPAN
>  <A HREF="#t%3APipeMode"
>PipeMode</A
>  </TD
></TR
><TR
><TD CLASS="body"
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="decl"
>= <A HREF="#v%3AReadFromPipe"
>ReadFromPipe</A
></TD
></TR
><TR
><TD CLASS="decl"
>| <A HREF="#v%3AWriteToPipe"
>WriteToPipe</A
></TD
></TR
></TABLE
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3ApOpen"
>pOpen</A
> ::  <A HREF="System-Cmd-Utils.html#t%3APipeMode"
>PipeMode</A
> -&gt; <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; (<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/GHC-IO-Handle.html#t%3AHandle"
>Handle</A
> -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> a) -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> a</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3ApOpen3"
>pOpen3</A
> ::  <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-Posix-Types.html#t%3AFd"
>Fd</A
> -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-Posix-Types.html#t%3AFd"
>Fd</A
> -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-Posix-Types.html#t%3AFd"
>Fd</A
> -&gt; <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; (<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-Posix-Types.html#t%3AProcessID"
>ProcessID</A
> -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> a) -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> <A HREF="/usr/share/doc/ghc/html/libraries/ghc-prim-0.2.0.0/GHC-Unit.html#t%3A%28%29"
>()</A
> -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> a</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3ApOpen3Raw"
>pOpen3Raw</A
> :: <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-Posix-Types.html#t%3AFd"
>Fd</A
> -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-Posix-Types.html#t%3AFd"
>Fd</A
> -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-Posix-Types.html#t%3AFd"
>Fd</A
> -&gt; <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> <A HREF="/usr/share/doc/ghc/html/libraries/ghc-prim-0.2.0.0/GHC-Unit.html#t%3A%28%29"
>()</A
> -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-Posix-Types.html#t%3AProcessID"
>ProcessID</A
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section1"
><A NAME="1"
><A NAME="1"
>High-Level Tools
</A
></A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="topdecl"
><TABLE CLASS="declbar"
><TR
><TD CLASS="declname"
><SPAN CLASS="keyword"
>data</SPAN
>  <A NAME="t:PipeHandle"
><A NAME="t%3APipeHandle"
></A
></A
><B
>PipeHandle</B
>  </TD
><TD CLASS="declbut"
><A HREF="src/System-Cmd-Utils.html#PipeHandle"
>Source</A
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="body"
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="ndoc"
>Return value from <TT
><A HREF="System-Cmd-Utils.html#v%3ApipeFrom"
>pipeFrom</A
></TT
>, <TT
><A HREF="System-Cmd-Utils.html#v%3ApipeLinesFrom"
>pipeLinesFrom</A
></TT
>, <TT
><A HREF="System-Cmd-Utils.html#v%3ApipeTo"
>pipeTo</A
></TT
>, or
<TT
><A HREF="System-Cmd-Utils.html#v%3ApipeBoth"
>pipeBoth</A
></TT
>.  Contains both a ProcessID and the original command that was
executed.  If you prefer not to use <TT
><A HREF="System-Cmd-Utils.html#v%3AforceSuccess"
>forceSuccess</A
></TT
> on the result of one
of these pipe calls, you can use (processID ph), assuming ph is your <TT
><A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
></TT
>,
as a parameter to <TT
><A HREF="/usr/share/doc/ghc/html/libraries/unix-2.4.0.2/System-Posix-Process.html#v%3AgetProcessStatus"
>getProcessStatus</A
></TT
>. 
</TD
></TR
><TR
><TD CLASS="section4"
>Constructors</TD
></TR
><TR
><TD CLASS="body"
><TABLE CLASS="vanilla" CELLSPACING="5" CELLPADDING="0"
><TR
><TD CLASS="arg"
><A NAME="v:PipeHandle"
><A NAME="v%3APipeHandle"
></A
></A
><B
>PipeHandle</B
></TD
><TD CLASS="rdoc"
></TD
></TR
><TR
><TD CLASS="body" COLSPAN="2"
><TABLE CLASS="vanilla" CELLSPACING="1" CELLPADDING="0"
><TR
><TD CLASS="arg"
><A NAME="v:processID"
><A NAME="v%3AprocessID"
></A
></A
><B
>processID</B
> :: <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-Posix-Types.html#t%3AProcessID"
>ProcessID</A
></TD
><TD CLASS="rdoc"
></TD
></TR
><TR
><TD CLASS="arg"
><A NAME="v:phCommand"
><A NAME="v%3AphCommand"
></A
></A
><B
>phCommand</B
> :: <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
></TD
><TD CLASS="rdoc"
></TD
></TR
><TR
><TD CLASS="arg"
><A NAME="v:phArgs"
><A NAME="v%3AphArgs"
></A
></A
><B
>phArgs</B
> :: [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>]</TD
><TD CLASS="rdoc"
></TD
></TR
><TR
><TD CLASS="arg"
><A NAME="v:phCreator"
><A NAME="v%3AphCreator"
></A
></A
><B
>phCreator</B
> :: <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
></TD
><TD CLASS="rdoc"
>Function that created it
</TD
></TR
></TABLE
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="section4"
><IMG SRC="minus.gif" CLASS="coll" ONCLICK="toggle(this,'i:PipeHandle')" ALT="show/hide"
> Instances</TD
></TR
><TR
><TD CLASS="body"
><DIV ID="i:PipeHandle" STYLE="display:block;"
><TABLE CLASS="vanilla" CELLSPACING="1" CELLPADDING="0"
><TR
><TD CLASS="decl"
><A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Eq.html#t%3AEq"
>Eq</A
> <A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Text-Show.html#t%3AShow"
>Show</A
> <A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
></TD
></TR
></TABLE
></DIV
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="topdecl"
><TABLE CLASS="declbar"
><TR
><TD CLASS="declname"
><A NAME="v:safeSystem"
><A NAME="v%3AsafeSystem"
></A
></A
><B
>safeSystem</B
> :: <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> <A HREF="/usr/share/doc/ghc/html/libraries/ghc-prim-0.2.0.0/GHC-Unit.html#t%3A%28%29"
>()</A
></TD
><TD CLASS="declbut"
><A HREF="src/System-Cmd-Utils.html#safeSystem"
>Source</A
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="doc"
><P
>Invokes the specified command in a subprocess, waiting for the result.
If the command terminated successfully, return normally.  Otherwise,
raises a userError with the problem.
</P
><P
>Implemented in terms of <TT
><A HREF="System-Cmd-Utils.html#v%3AposixRawSystem"
>posixRawSystem</A
></TT
> where supported, and System.Posix.rawSystem otherwise.
</P
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="topdecl"
><TABLE CLASS="declbar"
><TR
><TD CLASS="declname"
><A NAME="v:forceSuccess"
><A NAME="v%3AforceSuccess"
></A
></A
><B
>forceSuccess</B
> :: <A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
> -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> <A HREF="/usr/share/doc/ghc/html/libraries/ghc-prim-0.2.0.0/GHC-Unit.html#t%3A%28%29"
>()</A
></TD
><TD CLASS="declbut"
><A HREF="src/System-Cmd-Utils.html#forceSuccess"
>Source</A
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="doc"
><P
>Uses <TT
><A HREF="/usr/share/doc/ghc/html/libraries/unix-2.4.0.2/System-Posix-Process.html#v%3AgetProcessStatus"
>getProcessStatus</A
></TT
> to obtain the exit status
of the given process ID.  If the process terminated normally, does nothing.
Otherwise, raises an exception with an appropriate error message.
</P
><P
>This call will block waiting for the given pid to terminate.
</P
><P
>Not available on Windows. 
</P
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="topdecl"
><TABLE CLASS="declbar"
><TR
><TD CLASS="declname"
><A NAME="v:posixRawSystem"
><A NAME="v%3AposixRawSystem"
></A
></A
><B
>posixRawSystem</B
> :: <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> <A HREF="/usr/share/doc/ghc/html/libraries/unix-2.4.0.2/System-Posix-Process-Internals.html#t%3AProcessStatus"
>ProcessStatus</A
></TD
><TD CLASS="declbut"
><A HREF="src/System-Cmd-Utils.html#posixRawSystem"
>Source</A
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="doc"
><P
>Invokes the specified command in a subprocess, waiting for the result.
Return the result status.  Never raises an exception.  Only available
on POSIX platforms.
</P
><P
>Like system(3), this command ignores SIGINT and SIGQUIT and blocks SIGCHLD
during its execution.
</P
><P
>Logs as System.Cmd.Utils.posixRawSystem 
</P
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="topdecl"
><TABLE CLASS="declbar"
><TR
><TD CLASS="declname"
><A NAME="v:forkRawSystem"
><A NAME="v%3AforkRawSystem"
></A
></A
><B
>forkRawSystem</B
> :: <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-Posix-Types.html#t%3AProcessID"
>ProcessID</A
></TD
><TD CLASS="declbut"
><A HREF="src/System-Cmd-Utils.html#forkRawSystem"
>Source</A
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="doc"
><P
>Invokes the specified command in a subprocess, without waiting for
the result.  Returns the PID of the subprocess -- it is YOUR responsibility
to use getProcessStatus or getAnyProcessStatus on that at some point.  Failure
to do so will lead to resource leakage (zombie processes).
</P
><P
>This function does nothing with signals.  That too is up to you.
</P
><P
>Logs as System.Cmd.Utils.forkRawSystem 
</P
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section2"
><A NAME="2"
><A NAME="2"
>Piping with lazy strings
</A
></A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="topdecl"
><TABLE CLASS="declbar"
><TR
><TD CLASS="declname"
><A NAME="v:pipeFrom"
><A NAME="v%3ApipeFrom"
></A
></A
><B
>pipeFrom</B
> :: <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> (<A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
>, <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>)</TD
><TD CLASS="declbut"
><A HREF="src/System-Cmd-Utils.html#pipeFrom"
>Source</A
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="doc"
><P
>Read data from a pipe.  Returns a lazy string and a <TT
><A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
></TT
>.
</P
><P
>ONLY AFTER the string has been read completely, You must call either
<TT
><A HREF="/usr/share/doc/ghc/html/libraries/unix-2.4.0.2/System-Posix-Process.html#v%3AgetProcessStatus"
>getProcessStatus</A
></TT
> or <TT
><A HREF="System-Cmd-Utils.html#v%3AforceSuccess"
>forceSuccess</A
></TT
> on the <TT
><A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
></TT
>.
Zombies will result otherwise.
</P
><P
>Not available on Windows.
</P
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="topdecl"
><TABLE CLASS="declbar"
><TR
><TD CLASS="declname"
><A NAME="v:pipeLinesFrom"
><A NAME="v%3ApipeLinesFrom"
></A
></A
><B
>pipeLinesFrom</B
> :: <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> (<A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
>, [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>])</TD
><TD CLASS="declbut"
><A HREF="src/System-Cmd-Utils.html#pipeLinesFrom"
>Source</A
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="doc"
><P
>Like <TT
><A HREF="System-Cmd-Utils.html#v%3ApipeFrom"
>pipeFrom</A
></TT
>, but returns data in lines instead of just a String.
Shortcut for calling lines on the result from <TT
><A HREF="System-Cmd-Utils.html#v%3ApipeFrom"
>pipeFrom</A
></TT
>.
</P
><P
>Note: this function logs as pipeFrom.
</P
><P
>Not available on Windows. 
</P
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="topdecl"
><TABLE CLASS="declbar"
><TR
><TD CLASS="declname"
><A NAME="v:pipeTo"
><A NAME="v%3ApipeTo"
></A
></A
><B
>pipeTo</B
> :: <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
> -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> <A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
></TD
><TD CLASS="declbut"
><A HREF="src/System-Cmd-Utils.html#pipeTo"
>Source</A
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="doc"
><P
>Write data to a pipe.  Returns a ProcessID.
</P
><P
>You must call either
<TT
><A HREF="/usr/share/doc/ghc/html/libraries/unix-2.4.0.2/System-Posix-Process.html#v%3AgetProcessStatus"
>getProcessStatus</A
></TT
> or <TT
><A HREF="System-Cmd-Utils.html#v%3AforceSuccess"
>forceSuccess</A
></TT
> on the ProcessID.
Zombies will result otherwise.
</P
><P
>Not available on Windows.
</P
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="topdecl"
><TABLE CLASS="declbar"
><TR
><TD CLASS="declname"
><A NAME="v:pipeBoth"
><A NAME="v%3ApipeBoth"
></A
></A
><B
>pipeBoth</B
> :: <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
> -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> (<A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
>, <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>)</TD
><TD CLASS="declbut"
><A HREF="src/System-Cmd-Utils.html#pipeBoth"
>Source</A
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="doc"
><P
>Like a combination of <TT
><A HREF="System-Cmd-Utils.html#v%3ApipeTo"
>pipeTo</A
></TT
> and <TT
><A HREF="System-Cmd-Utils.html#v%3ApipeFrom"
>pipeFrom</A
></TT
>; forks an IO thread
to send data to the piped program, and simultaneously returns its output
stream.
</P
><P
>The same note about checking the return status applies here as with <TT
><A HREF="System-Cmd-Utils.html#v%3ApipeFrom"
>pipeFrom</A
></TT
>.
</P
><P
>Not available on Windows. 
</P
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section2"
><A NAME="3"
><A NAME="3"
>Piping with handles
</A
></A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="topdecl"
><TABLE CLASS="declbar"
><TR
><TD CLASS="declname"
><A NAME="v:hPipeFrom"
><A NAME="v%3AhPipeFrom"
></A
></A
><B
>hPipeFrom</B
> :: <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> (<A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
>, <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/GHC-IO-Handle.html#t%3AHandle"
>Handle</A
>)</TD
><TD CLASS="declbut"
><A HREF="src/System-Cmd-Utils.html#hPipeFrom"
>Source</A
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="doc"
><P
>Read data from a pipe.  Returns a Handle and a <TT
><A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
></TT
>.
</P
><P
>When done, you must hClose the handle, and then use either <TT
><A HREF="System-Cmd-Utils.html#v%3AforceSuccess"
>forceSuccess</A
></TT
> or
getProcessStatus on the <TT
><A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
></TT
>.  Zombies will result otherwise.
</P
><P
>This function logs as pipeFrom.
</P
><P
>Not available on Windows or with Hugs.
</P
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="topdecl"
><TABLE CLASS="declbar"
><TR
><TD CLASS="declname"
><A NAME="v:hPipeTo"
><A NAME="v%3AhPipeTo"
></A
></A
><B
>hPipeTo</B
> :: <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> (<A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
>, <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/GHC-IO-Handle.html#t%3AHandle"
>Handle</A
>)</TD
><TD CLASS="declbut"
><A HREF="src/System-Cmd-Utils.html#hPipeTo"
>Source</A
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="doc"
><P
>Write data to a pipe.  Returns a <TT
><A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
></TT
> and a new Handle to write
to.
</P
><P
>When done, you must hClose the handle, and then use either <TT
><A HREF="System-Cmd-Utils.html#v%3AforceSuccess"
>forceSuccess</A
></TT
> or
getProcessStatus on the <TT
><A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
></TT
>.  Zombies will result otherwise.
</P
><P
>This function logs as pipeTo.
</P
><P
>Not available on Windows.
</P
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="topdecl"
><TABLE CLASS="declbar"
><TR
><TD CLASS="declname"
><A NAME="v:hPipeBoth"
><A NAME="v%3AhPipeBoth"
></A
></A
><B
>hPipeBoth</B
> :: <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> (<A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
>, <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/GHC-IO-Handle.html#t%3AHandle"
>Handle</A
>, <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/GHC-IO-Handle.html#t%3AHandle"
>Handle</A
>)</TD
><TD CLASS="declbut"
><A HREF="src/System-Cmd-Utils.html#hPipeBoth"
>Source</A
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="doc"
><P
>Like a combination of <TT
><A HREF="System-Cmd-Utils.html#v%3AhPipeTo"
>hPipeTo</A
></TT
> and <TT
><A HREF="System-Cmd-Utils.html#v%3AhPipeFrom"
>hPipeFrom</A
></TT
>; returns
a 3-tuple of (<TT
><A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
></TT
>, Data From Pipe, Data To Pipe).
</P
><P
>When done, you must hClose both handles, and then use either <TT
><A HREF="System-Cmd-Utils.html#v%3AforceSuccess"
>forceSuccess</A
></TT
> or
getProcessStatus on the <TT
><A HREF="System-Cmd-Utils.html#t%3APipeHandle"
>PipeHandle</A
></TT
>.  Zombies will result otherwise.
</P
><P
>Hint: you will usually need to ForkIO a thread to handle one of the Handles;
otherwise, deadlock can result.
</P
><P
>This function logs as pipeBoth.
</P
><P
>Not available on Windows.
</P
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section1"
><A NAME="4"
><A NAME="4"
>Low-Level Tools
</A
></A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="topdecl"
><TABLE CLASS="declbar"
><TR
><TD CLASS="declname"
><SPAN CLASS="keyword"
>data</SPAN
>  <A NAME="t:PipeMode"
><A NAME="t%3APipeMode"
></A
></A
><B
>PipeMode</B
>  </TD
><TD CLASS="declbut"
><A HREF="src/System-Cmd-Utils.html#PipeMode"
>Source</A
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="body"
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="section4"
>Constructors</TD
></TR
><TR
><TD CLASS="body"
><TABLE CLASS="vanilla" CELLSPACING="1" CELLPADDING="0"
><TR
><TD CLASS="arg"
><A NAME="v:ReadFromPipe"
><A NAME="v%3AReadFromPipe"
></A
></A
><B
>ReadFromPipe</B
></TD
><TD CLASS="rdoc"
></TD
></TR
><TR
><TD CLASS="arg"
><A NAME="v:WriteToPipe"
><A NAME="v%3AWriteToPipe"
></A
></A
><B
>WriteToPipe</B
></TD
><TD CLASS="rdoc"
></TD
></TR
></TABLE
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="topdecl"
><TABLE CLASS="declbar"
><TR
><TD CLASS="declname"
><A NAME="v:pOpen"
><A NAME="v%3ApOpen"
></A
></A
><B
>pOpen</B
> ::  <A HREF="System-Cmd-Utils.html#t%3APipeMode"
>PipeMode</A
> -&gt; <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
> -&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>] -&gt; (<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/GHC-IO-Handle.html#t%3AHandle"
>Handle</A
> -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> a) -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> a</TD
><TD CLASS="declbut"
><A HREF="src/System-Cmd-Utils.html#pOpen"
>Source</A
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="doc"
><P
>Open a pipe to the specified command.
</P
><P
>Passes the handle on to the specified function.
</P
><P
>The <TT
><A HREF="System-Cmd-Utils.html#t%3APipeMode"
>PipeMode</A
></TT
> specifies what you will be doing.  That is, specifing <TT
><A HREF="System-Cmd-Utils.html#v%3AReadFromPipe"
>ReadFromPipe</A
></TT
>
sets up a pipe from stdin, and <TT
><A HREF="System-Cmd-Utils.html#v%3AWriteToPipe"
>WriteToPipe</A
></TT
> sets up a pipe from stdout.
</P
><P
>Not available on Windows.
</P
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="topdecl"
><TABLE CLASS="declbar"
><TR
><TD CLASS="declname"
><A NAME="v:pOpen3"
><A NAME="v%3ApOpen3"
></A
></A
><B
>pOpen3</B
></TD
><TD CLASS="declbut"
><A HREF="src/System-Cmd-Utils.html#pOpen3"
>Source</A
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="body"
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="arg"
>:: <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-Posix-Types.html#t%3AFd"
>Fd</A
></TD
><TD CLASS="rdoc"
>Send stdin to this fd
</TD
></TR
><TR
><TD CLASS="arg"
>-&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-Posix-Types.html#t%3AFd"
>Fd</A
></TD
><TD CLASS="rdoc"
>Get stdout from this fd
</TD
></TR
><TR
><TD CLASS="arg"
>-&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-Posix-Types.html#t%3AFd"
>Fd</A
></TD
><TD CLASS="rdoc"
>Get stderr from this fd
</TD
></TR
><TR
><TD CLASS="arg"
>-&gt; <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
></TD
><TD CLASS="rdoc"
>Command to run
</TD
></TR
><TR
><TD CLASS="arg"
>-&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>]</TD
><TD CLASS="rdoc"
>Command args
</TD
></TR
><TR
><TD CLASS="arg"
>-&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-Posix-Types.html#t%3AProcessID"
>ProcessID</A
> -&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> a</TD
><TD CLASS="rdoc"
>Action to run in parent
</TD
></TR
><TR
><TD CLASS="arg"
>-&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> <A HREF="/usr/share/doc/ghc/html/libraries/ghc-prim-0.2.0.0/GHC-Unit.html#t%3A%28%29"
>()</A
></TD
><TD CLASS="rdoc"
>Action to run in child before execing (if you don't need something, set this to <TT
>return ()</TT
>) -- IGNORED IN HUGS
</TD
></TR
><TR
><TD CLASS="arg"
>-&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> a</TD
><TD CLASS="rdoc"
></TD
></TR
><TR
><TD CLASS="ndoc" COLSPAN="2"
><P
>Runs a command, redirecting things to pipes.
</P
><P
>Not available on Windows.
</P
><P
>Note that you may not use the same fd on more than one item.  If you
want to redirect stdout and stderr, dup it first.
</P
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="topdecl"
><TABLE CLASS="declbar"
><TR
><TD CLASS="declname"
><A NAME="v:pOpen3Raw"
><A NAME="v%3ApOpen3Raw"
></A
></A
><B
>pOpen3Raw</B
></TD
><TD CLASS="declbut"
><A HREF="src/System-Cmd-Utils.html#pOpen3Raw"
>Source</A
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="body"
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="arg"
>:: <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-Posix-Types.html#t%3AFd"
>Fd</A
></TD
><TD CLASS="rdoc"
>Send stdin to this fd
</TD
></TR
><TR
><TD CLASS="arg"
>-&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-Posix-Types.html#t%3AFd"
>Fd</A
></TD
><TD CLASS="rdoc"
>Get stdout from this fd
</TD
></TR
><TR
><TD CLASS="arg"
>-&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-Posix-Types.html#t%3AFd"
>Fd</A
></TD
><TD CLASS="rdoc"
>Get stderr from this fd
</TD
></TR
><TR
><TD CLASS="arg"
>-&gt; <A HREF="System-IO-HVFS.html#t%3AFilePath"
>FilePath</A
></TD
><TD CLASS="rdoc"
>Command to run
</TD
></TR
><TR
><TD CLASS="arg"
>-&gt; [<A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/Data-Char.html#t%3AString"
>String</A
>]</TD
><TD CLASS="rdoc"
>Command args
</TD
></TR
><TR
><TD CLASS="arg"
>-&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> <A HREF="/usr/share/doc/ghc/html/libraries/ghc-prim-0.2.0.0/GHC-Unit.html#t%3A%28%29"
>()</A
></TD
><TD CLASS="rdoc"
>Action to run in child before execing (if you don't need something, set this to <TT
>return ()</TT
>) -- IGNORED IN HUGS
</TD
></TR
><TR
><TD CLASS="arg"
>-&gt; <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-IO.html#t%3AIO"
>IO</A
> <A HREF="/usr/share/doc/ghc/html/libraries/base-4.2.0.2/System-Posix-Types.html#t%3AProcessID"
>ProcessID</A
></TD
><TD CLASS="rdoc"
></TD
></TR
><TR
><TD CLASS="ndoc" COLSPAN="2"
><P
>Runs a command, redirecting things to pipes.
</P
><P
>Not available on Windows.
</P
><P
>Returns immediately with the PID of the child.  Using waitProcess on it
is YOUR responsibility!
</P
><P
>Note that you may not use the same fd on more than one item.  If you
want to redirect stdout and stderr, dup it first.
</P
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="botbar"
>Produced by <A HREF="http://www.haskell.org/haddock/"
>Haddock</A
> version 2.6.1</TD
></TR
></TABLE
></BODY
></HTML
>