X-Git-Url: http://mj.ucw.cz/gitweb/?a=blobdiff_plain;f=lib%2Fmmap.c;h=1393a6b1cdf380ab4ee463e05ddee4650147e11c;hb=724d132f7de291fecc65819891aa44e07abdc410;hp=62101f8d66a210c16225765c48cfc48e83f13e4f;hpb=1571781022499a9d0c32d249f89945d034d1cbff;p=libucw.git

diff --git a/lib/mmap.c b/lib/mmap.c
index 62101f8d..1393a6b1 100644
--- a/lib/mmap.c
+++ b/lib/mmap.c
@@ -1,7 +1,10 @@
 /*
  *	Sherlock Library -- Mapping of Files
  *
- *	(c) 1999 Martin Mares <mj@ucw.cz>
+ *	(c) 1999--2002 Martin Mares <mj@ucw.cz>
+ *
+ *	This software may be freely distributed and used according to the terms
+ *	of the GNU Lesser General Public License.
  */
 
 #include "lib/lib.h"
@@ -12,29 +15,33 @@
 #include <sys/stat.h>
 #include <sys/mman.h>
 
-#ifndef MAP_FAILED
-#define MAP_FAILED ((void *)-1L)
-#endif
-
 void *
-mmap_file(byte *name, unsigned *len)
+mmap_file(byte *name, unsigned *len, int writeable)
 {
-  int fd = open(name, O_RDONLY);
+  int fd = open(name, writeable ? O_RDWR : O_RDONLY);
   struct stat st;
   void *x;
 
   if (fd < 0)
-    return NULL;
+    die("open(%s): %m", name);
   if (fstat(fd, &st) < 0)
-    x = NULL;
-  else
+    die("fstat(%s): %m", name);
+  if (len)
+    *len = st.st_size;
+  if (st.st_size)
     {
-      if (len)
-	*len = st.st_size;
-      x = mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, fd, 0);
+      x = mmap(NULL, st.st_size, writeable ? (PROT_READ | PROT_WRITE) : PROT_READ, MAP_SHARED, fd, 0);
       if (x == MAP_FAILED)
-	x = NULL;
+	die("mmap(%s): %m", name);
     }
+  else	/* For empty file, we can return any non-zero address */
+    x = "";
   close(fd);
   return x;
 }
+
+void
+munmap_file(void *start, unsigned len)
+{
+  munmap(start, len);
+}