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Diffstat (limited to 'compat/Compat/RawSystem.hs')
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1 files changed, 0 insertions, 156 deletions
diff --git a/compat/Compat/RawSystem.hs b/compat/Compat/RawSystem.hs deleted file mode 100644 index f0f8aa3ac7..0000000000 --- a/compat/Compat/RawSystem.hs +++ /dev/null @@ -1,156 +0,0 @@ -{-# OPTIONS -cpp #-} ------------------------------------------------------------------------------ --- | --- Module : Compat.RawSystem --- Copyright : (c) The University of Glasgow 2001-2004 --- License : BSD-style (see the file libraries/base/LICENSE) --- --- Maintainer : libraries@haskell.org --- Stability : provisional --- Portability : portable --- --- This is an implementation of rawSystem for use on older versions of GHC --- which had missing or buggy implementations of this function. --- ------------------------------------------------------------------------------ - -module Compat.RawSystem (rawSystem) where - -#include "../../includes/ghcconfig.h" - -#if __GLASGOW_HASKELL__ >= 603 - -import System.Cmd (rawSystem) - -#else /* to end of file */ - -import System.Exit -import Foreign -import Foreign.C - -{- | -The computation @'rawSystem' cmd args@ runs the operating system command -whose file name is @cmd@, passing it the arguments @args@. It -bypasses the shell, so that @cmd@ should see precisely the argument -strings @args@, with no funny escaping or shell meta-syntax expansion. -(Unix users will recognise this behaviour -as @execvp@, and indeed that's how it's implemented.) -It will therefore behave more portably between operating systems than 'system'. - -The return codes are the same as for 'system'. --} - -rawSystem :: FilePath -> [String] -> IO ExitCode - -{- ------------------------------------------------------------------------- - IMPORTANT IMPLEMENTATION NOTES - (see also libraries/base/cbits/rawSystem.c) - -On Unix, rawSystem is easy to implement: use execvp. - -On Windows it's more tricky. We use CreateProcess, passing a single -command-line string (lpCommandLine) as its argument. (CreateProcess -is well documented on http://msdn.microsoft/com.) - - - It parses the beginning of the string to find the command. If the - file name has embedded spaces, it must be quoted, using double - quotes thus - "foo\this that\cmd" arg1 arg2 - - - The invoked command can in turn access the entire lpCommandLine string, - and the C runtime does indeed do so, parsing it to generate the - traditional argument vector argv[0], argv[1], etc. It does this - using a complex and arcane set of rules which are described here: - - http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vccelng/htm/progs_12.asp - - (if this URL stops working, you might be able to find it by - searching for "Parsing C Command-Line Arguments" on MSDN. Also, - the code in the Microsoft C runtime that does this translation - is shipped with VC++). - - -Our goal in rawSystem is to take a command filename and list of -arguments, and construct a string which inverts the translatsions -described above, such that the program at the other end sees exactly -the same arguments in its argv[] that we passed to rawSystem. - -This inverse translation is implemented by 'translate' below. - -Here are some pages that give informations on Windows-related -limitations and deviations from Unix conventions: - - http://support.microsoft.com/default.aspx?scid=kb;en-us;830473 - Command lines and environment variables effectively limited to 8191 - characters on Win XP, 2047 on NT/2000 (probably even less on Win 9x): - - http://www.microsoft.com/windowsxp/home/using/productdoc/en/default.asp?url=/WINDOWSXP/home/using/productdoc/en/percent.asp - Command-line substitution under Windows XP. IIRC these facilities (or at - least a large subset of them) are available on Win NT and 2000. Some - might be available on Win 9x. - - http://www.microsoft.com/windowsxp/home/using/productdoc/en/default.asp?url=/WINDOWSXP/home/using/productdoc/en/Cmd.asp - How CMD.EXE processes command lines. - - -Note: CreateProcess does have a separate argument (lpApplicationName) -with which you can specify the command, but we have to slap the -command into lpCommandLine anyway, so that argv[0] is what a C program -expects (namely the application name). So it seems simpler to just -use lpCommandLine alone, which CreateProcess supports. - ------------------------------------------------------------------------------ -} - -#ifndef mingw32_HOST_OS - -rawSystem cmd args = - withCString cmd $ \pcmd -> - withMany withCString (cmd:args) $ \cstrs -> - withArray0 nullPtr cstrs $ \arr -> do - status <- throwErrnoIfMinus1 "rawSystem" (c_rawSystem pcmd arr) - case status of - 0 -> return ExitSuccess - n -> return (ExitFailure n) - -foreign import ccall unsafe "rawSystem" - c_rawSystem :: CString -> Ptr CString -> IO Int - -#else - --- On Windows, the command line is passed to the operating system as --- a single string. Command-line parsing is done by the executable --- itself. -rawSystem cmd args = do - -- NOTE: 'cmd' is assumed to contain the application to run _only_, - -- as it'll be quoted surrounded in quotes here. - let cmdline = translate cmd ++ concat (map ((' ':) . translate) args) - withCString cmdline $ \pcmdline -> do - status <- throwErrnoIfMinus1 "rawSystem" (c_rawSystem pcmdline) - case status of - 0 -> return ExitSuccess - n -> return (ExitFailure n) - -translate :: String -> String -translate str@('"':_) = str -- already escaped. - -- ToDo: this case is wrong. It is only here because we - -- abuse the system in GHC's SysTools by putting arguments into - -- the command name; at some point we should fix it up and remove - -- the case above. -translate str = '"' : snd (foldr escape (True,"\"") str) - where escape '"' (b, str) = (True, '\\' : '"' : str) - escape '\\' (True, str) = (True, '\\' : '\\' : str) - escape '\\' (False, str) = (False, '\\' : str) - escape c (b, str) = (False, c : str) - -- See long comment above for what this function is trying to do. - -- - -- The Bool passed back along the string is True iff the - -- rest of the string is a sequence of backslashes followed by - -- a double quote. - -foreign import ccall unsafe "rawSystem" - c_rawSystem :: CString -> IO Int - -#endif - -#endif - |