[project @ 2001-12-18 10:37:52 by simonmar]

Allow opening char & block devices with openFile.  Opening a char
device gets you a stream, and a block device a file (these are
heuristics since we can't really tell without trying to lseek() on the
device whether it supports seeking or not, but the defaults are at
least safe).

diff --git a/ghc/lib/std/PrelPosix.hsc b/ghc/lib/std/PrelPosix.hsc
index 35dacc6..c18124d 100644 (file)
--- a/ghc/lib/std/PrelPosix.hsc
+++ b/ghc/lib/std/PrelPosix.hsc
@@ -86,10 +86,16 @@ fdType fd =
        c_fstat (fromIntegral fd) p_stat
     c_mode <- (#peek struct stat, st_mode) p_stat :: IO CMode
     case () of
-      _ | s_isdir c_mode                    -> return Directory
-        | s_isfifo c_mode || s_issock c_mode -> return Stream
-        | s_isreg c_mode                    -> return RegularFile
-        | otherwise                         -> ioException ioe_unknownfiletype
+      _ |  s_isdir  c_mode  -> return Directory
+        |  s_isfifo c_mode  -> return Stream
+       |  s_issock c_mode  -> return Stream
+       |  s_ischr  c_mode  -> return Stream
+       |  s_isreg  c_mode  -> return RegularFile
+       |  s_isblk  c_mode  -> return RegularFile
+       | otherwise         -> ioException ioe_unknownfiletype
+    -- we consider character devices to be streams (eg. ttys),
+    -- whereas block devices are more like regular files because they
+    -- are seekable.
 
 ioe_unknownfiletype = IOError Nothing UnsupportedOperation "fdType"
                        "unknown file type" Nothing
@@ -103,6 +109,12 @@ foreign import "s_isdir_PrelPosix_wrap" unsafe s_isdir :: CMode -> Bool
 foreign import "s_isfifo_PrelPosix_wrap" unsafe s_isfifo :: CMode -> Bool
 #def inline int s_isfifo_PrelPosix_wrap(m) { return S_ISFIFO(m); }
 
+foreign import "s_ischr_PrelPosix_wrap" unsafe s_ischr :: CMode -> Bool
+#def inline int s_ischr_PrelPosix_wrap(m) { return S_ISCHR(m); }
+
+foreign import "s_isblk_PrelPosix_wrap" unsafe s_isblk :: CMode -> Bool
+#def inline int s_isblk_PrelPosix_wrap(m) { return S_ISBLK(m); }
+
 #ifndef mingw32_TARGET_OS
 foreign import "s_issock_PrelPosix_wrap" unsafe s_issock :: CMode -> Bool
 #def inline int s_issock_PrelPosix_wrap(m) { return S_ISSOCK(m); }