* Fix bug ID #0035596: better detection of vcs device

git-svn-id: trunk@42766 -

rtl/linux/linuxvcs.pp

@@ -82,73 +82,59 @@ end;
 procedure detect_linuxvcs;
 
 var f:text;
-    f_open : boolean;
-    c,pc:char;
-    pid,cpid,dummy:longint;
-    device:dword;
+    fields:array [0..60] of int64;
+    fieldct,i:integer;
+    pid,ppid:longint;
+    magnitude:int64;
     s:string[15];
+    statln:ansistring;
 
 begin
   {Extremely aggressive VCSA detection. Works even through Midnight
    Commander. Idea from the C++ Turbo Vision project, credits go
    to Martynas Kunigelis <[email protected]>.}
   pid:=fpgetpid;
-  f_open:=false;
-  {$push}
-  {$I-}
-  {$R-}
   repeat
-    cpid:=pid;
     str(pid,s);
-    assign(f,'/proc/'+s+'/stat');
+    assign(f, '/proc/'+s+'/stat');
+    {$I-}
     reset(f);
+    {$I+}
     if ioresult<>0 then
-      exit;
-    f_open:=true;
-    { from here we can discard I/O errors, as long as we avoid
-      infinite loops }
-    { first number is pid }
-    dummy:=0;
-    read(f,dummy);
-    if dummy<>pid then
-      exit;
-    { after comes the name of the binary within (), look for closing brace followed by space }
-    c:=#0;
-    repeat
-      pc:=c;
-      read(f,c);
-      if ioresult<>0 then
-        break;
-    until (pc=')') and (c=' ');
-    { now comes the state letter }
-    repeat
-      read(f,c);
-      if ioresult<>0 then
-        break;
-    until c=' ';
-    { parent pid }
-    pid:=-1;
-    read(f,pid);
-    { process group }
-    read(f,dummy);
-    { session }
-    read(f,dummy);
-    { device number }
-    device:=0;
-    read(f,device);
+      break;
+    readln(f, statln);
     close(f);
-    f_open:=false;
-    if (device and $ffffffc0)=$00000400 then {/dev/tty*}
+    magnitude := 1;
+    fieldct := 0;
+    fields[fieldct] := 0;
+    for i := high(statln) downto low(statln) do
       begin
-        vcs_device:=device and $3f;
+        case statln[i] of
+          '-': magnitude := -1;
+          '0'..'9': begin
+            fields[fieldct] := fields[fieldct]
+                               + (magnitude * (ord(statln[i]) - ord('0')));
+            magnitude := magnitude * 10;
+          end;
+          ' ': begin
+            magnitude := 1;
+            fieldct := fieldct + 1;
+            fields[fieldct] := 0;
+          end;
+        else
+          break;
+        end;
+      end;
+    ppid := pid;
+    pid := fields[fieldct - 1];
+    if (fields[fieldct - 4] and $ffffffc0) = $00000400 then {/dev/tty*}
+      begin
+        vcs_device:=fields[fieldct - 4] and $3f;
         break;
       end;
-  until (device=0) {Not attached to a terminal, i.e. an xterm.}
-      or (pid=-1)
-      or (cpid=pid);
-  if f_open then
-    close(f);
-  {$pop}
+  until (fields[fieldct - 4]=0) {Not attached to a terminal, i.e. an xterm.}
+        or (pid=-1)
+        or (ppid=pid);
 end;
 
 begin