Hack to read /proc filesystem

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@10311 72102866-910b-0410-8b05-ffd578937521

ChangeLog

@@ -1,3 +1,9 @@
+2001-07-07  Richard Frith-Macdonald <rfm@gnu.org>
+
+	* Source/NSData.m: readContentsOfFile() hack added to permit reading
+	of files like those in the /proc filesystem which don't support
+	lengths.
+
 2001-07-02  Richard Frith-Macdonald <rfm@gnu.org>
 
 	* Source/NSString.m: Never init nocopy with null pointer - increase

Source/NSData.m

@@ -200,7 +200,8 @@ readContentsOfFile(NSString* path, void** buf, unsigned* len, NSZone* zone)
 
   if (theFile == NULL)		/* We failed to open the file. */
     {
-      NSDebugLog(@"Open (%s) attempt failed - %s", thePath, GSLastErrorStr(errno));
+      NSDebugLog(@"Open (%s) attempt failed - %s", thePath,
+	GSLastErrorStr(errno));
       goto failure;
     }
 
@@ -225,6 +226,56 @@ readContentsOfFile(NSString* path, void** buf, unsigned* len, NSZone* zone)
       goto failure;
     }
 
+  /*
+   *	Rewind the file pointer to the beginning, preparing to read in
+   *	the file.
+   */
+  c = fseek(theFile, 0L, SEEK_SET);
+  if (c != 0)
+    {
+      NSLog(@"Fseek to start of file failed - %s", GSLastErrorStr(errno));
+      goto failure;
+    }
+
+  if (fileLength == 0)
+    {
+      unsigned char	buf[BUFSIZ];
+
+      /*
+       * Special case ... a file of length zero may be a named pipe or some
+       * file in the /proc filesystem, which will return us data if we read
+       * from it ... so we try reading as much as we can.
+       */
+      while ((c = fread(buf, 1, BUFSIZ, theFile)) != 0)
+	{
+	  if (tmp == 0)
+	    {
+#if	GS_WITH_GC == 1
+	      tmp = NSZoneMalloc(GSAtomicMallocZone(), c);
+#else
+	      tmp = NSZoneMalloc(zone, c);
+#endif
+	    }
+	  else
+	    {
+#if	GS_WITH_GC == 1
+	      tmp = NSZoneRealloc(GSAtomicMallocZone(), tmp, fileLength + c);
+#else
+	      tmp = NSZoneRealloc(zone, tmp, fileLength + c);
+#endif
+	    }
+	  if (tmp == 0)
+	    {
+	      NSLog(@"Malloc failed for file of length %d - %s",
+		fileLength + c, GSLastErrorStr(errno));
+	      goto failure;
+	    }
+	  memcpy(tmp + fileLength, buf, c);
+	  fileLength += c;
+	}
+    }
+  else
+    {
 #if	GS_WITH_GC == 1
       tmp = NSZoneMalloc(GSAtomicMallocZone(), fileLength);
 #else
@@ -237,23 +288,13 @@ readContentsOfFile(NSString* path, void** buf, unsigned* len, NSZone* zone)
 	  goto failure;
 	}
 
-  /*
-   *	Rewind the file pointer to the beginning, preparing to read in
-   *	the file.
-   */
-  c = fseek(theFile, 0L, SEEK_SET);
-  if (c != 0)
-    {
-      NSLog(@"Fseek to start of file failed - %s", GSLastErrorStr(errno));
-      goto failure;
-    }
-
       c = fread(tmp, 1, fileLength, theFile);
       if (c != fileLength)
 	{
 	  NSLog(@"read of file contents failed - %s", GSLastErrorStr(errno));
 	  goto failure;
 	}
+    }
 
   *buf = tmp;
   *len = fileLength;

Testing/basic.m

@@ -8,6 +8,12 @@ int main ()
   id	pool = [NSAutoreleasePool new];
   id	o = [NSObject new];
   printf ("Hello from object at 0x%x\n", (unsigned)[o self]);
+
+  o = [NSString stringWithFormat: @"/proc/%d/status", getpid()];
+  NSLog(@"'%@'", o);
+  o = [NSString stringWithContentsOfFile: o];
+  NSLog(@"'%@'", o);
+
   exit (0);
 }
 #else