PATCH: zpty -t

PATCH: zpty -t

[Sven Wischnowsky]

I found a report about zpty -t not working properly on the debian bug
list. For example:

  % zpty z zsh
  % zpty -w z exit
  % zpty -r z
  % zpty -t z && echo running

printed `running'.

Below is my n+1'th attempt at making this better, not relying on
read_poll() in checkptycmd() (because that uses select() which
succeeds even if the process has terminated and there isn't really
anything to read).

Dunno if this is really any better, but at least it solves the problem 
above. What do the Cygwin folks say?

Bye
 Sven

Index: Src/Modules/zpty.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/Modules/zpty.c,v
retrieving revision 1.21
diff -u -r1.21 zpty.c
--- Src/Modules/zpty.c	2001/01/16 13:44:20	1.21
+++ Src/Modules/zpty.c	2001/02/13 13:12:00
@@ -430,13 +430,19 @@
 static void
 checkptycmd(Ptycmd cmd)
 {
-    if (cmd->read != -1)
+    char c;
+    int r;
+
+    if (cmd->read != -1 || cmd->fin)
 	return;
-    if (!read_poll(cmd->fd, &cmd->read, 0) &&
-	kill(cmd->pid, 0) < 0) {
-	cmd->fin = 1;
-	zclose(cmd->fd);
+    if ((r = read(cmd->fd, &c, 1)) < 0) {
+	if (kill(cmd->pid, 0) < 0) {
+	    cmd->fin = 1;
+	    zclose(cmd->fd);
+	}
+	return;
     }
+    if (r) cmd->read = (int) c;
 }
 
 static int

--
Sven Wischnowsky                         wischnow@informatik.hu-berlin.de

RE: PATCH: zpty -t

[Andrej Borsenkow]

>
> Dunno if this is really any better, but at least it solves the problem
> above. What do the Cygwin folks say?
>

make check says:

$ ZTST_verbose=1 ../Src/zsh.exe /tools/src/zsh/Test/ztst.zsh
/tools/src/zsh/Test/53completion.ztst
Test /tools/src/zsh/Test/53completion.ztst failed: non-zero status from
preparation code:
  comptestinit -z $ZTST_testdir/../Src/zsh

If I insert set -x before ``. .../comptest'' the whole hangs immediately after
the first 'zpty -r ...' from sub-zsh (to be precise, it is the last line
seen).

This looks like some timing problem. If I knew where :(

-andrej

RE: PATCH: zpty -t

[Andrej Borsenkow]

>
> This looks like some timing problem. If I knew where :(
>

I do not mean, it is related to this patch. Currently there is something fishy
anyway - ^Z does not work, nslookup does not work.

-andrej