I saw dtexec closing the pipe that it reads from to get stderr of the
program it launched.
That caused the client to die when issuing error messages to stderr.
Dtterm would die on startup because of otherwise unimportant warnings
about missing fonts.
The root of the problem is an assumption in dtexec that fstat will
report the number of readable
characters in a pipe as the st_size. Recent linux kernels always return
0 for st_size of a pipe.
This patch changes dtexec Main.c to use select to check if the pipe
is readable
and uses a read of zero bytes to notice when the other side of the pipe
is closed and
EOF is reached.
>From a127368f6b9e84ec03efa12316fc1149b8270629 Mon Sep 17 00:00:00 2001
From: Mike Stroyan <m...@stroyan.net>
Date: Sun, 9 Sep 2012 15:44:45 -0600
Subject: [PATCH] Don't use fstat for readable pipe chars in dtexec.
The dtexec code assumes that fstat reports pipe's readable chars.
Linux always reports 0 for st_size of a pipe.
Instead read one character when select reports readable.
Note EOF when select says readable but read returns 0.
---
cde/programs/dtexec/Main.c | 24 +++++++++++++-----------
1 file changed, 13 insertions(+), 11 deletions(-)
diff --git a/cde/programs/dtexec/Main.c b/cde/programs/dtexec/Main.c
index 3624588..60c6d22 100644
--- a/cde/programs/dtexec/Main.c
+++ b/cde/programs/dtexec/Main.c
@@ -1163,7 +1163,6 @@ main (
int junki,i;
char *tmpBuffer;
int errorBytes;
- struct stat statBuffer;
int firstPass, tmpi;
char *tmpProgName = NULL;
@@ -1390,28 +1389,31 @@ main (
firstPass = 1;
while (1) {
- if ( fstat(errorpipeG[0], &statBuffer) ) {
- break;
+ char buf;
+ nfound =select(MAXSOCKS, FD_SET_CAST(&readfds), FD_SET_CAST(NULL),
+ FD_SET_CAST(NULL), &timeoutShort);
+ if (nfound > 0) {
+ tmpi = read (errorpipeG[0], &buf, 1);
+ } else {
+ tmpi = 0;
}
- else if ( statBuffer.st_size > 0 ) {
+
+ if ( tmpi > 0 ) {
/*
* Grow buffer to hold entire error stream.
*/
firstPass = 0;
if (tmpBuffer == NULL)
tmpBuffer = (char *) malloc(
- statBuffer.st_size + 1);
+ tmpi + 1);
else
tmpBuffer = (char *) realloc( tmpBuffer,
- errorBytes +
- statBuffer.st_size + 1);
+ errorBytes + tmpi + 1);
/*
* Drain error pipe.
*/
- tmpi = read (errorpipeG[0], &tmpBuffer[errorBytes],
- statBuffer.st_size);
- if (tmpi > 0) /* else let fstat() redetect problem */
- errorBytes += tmpi;
+ tmpBuffer[errorBytes] = buf;
+ errorBytes += tmpi;
tmpBuffer[errorBytes] = '\0';
if (errorBytes < 65535) {
--
1.7.9.5
------------------------------------------------------------------------------
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and
threat landscape has changed and how IT managers can respond. Discussions
will include endpoint security, mobile security and the latest in malware
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
_______________________________________________
cdesktopenv-devel mailing list
cdesktopenv-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/cdesktopenv-devel
