[sw/supervision] paparazzi center: use input_line to read one line at…

… a time

* this should make error/warning/info coloration work properly
* on HUP signal just recursively read into a small buffer like we did before,
  since we might not get a newline at the end...
should fix #113

sw/supervision/pc_common.ml

@@ -37,14 +37,19 @@ let my_open_process_in = fun cmd ->
   Unix.close in_write;
   pid, inchan
 
-let buf_size = 1024
+let buf_size = 128
 
 let run_and_log = fun log com ->
   let com = com ^ " 2>&1" in
   let pid, com_stdout = my_open_process_in com in
   let channel_out = GMain.Io.channel_of_descr (Unix.descr_of_in_channel com_stdout) in
   let cb = fun ev ->
     if List.mem `IN ev then begin
+      (* read one line, add the newline again and log it *)
+      let line = input_line com_stdout in
+      log (line ^ "\n");
+      true
+    end else begin
       let buf = String.create buf_size in
       (* loop until input returns zero *)
       let rec log_input = fun out ->
@@ -56,8 +61,6 @@ let run_and_log = fun log com ->
         end;
       in
       log_input com_stdout;
-      true
-    end else begin
       log (sprintf "\nDONE (%s)\n\n" com);
       false
     end in