If all you have is the end of a pipe - it is hard to say what is on the other side. You could try and fish around in /proc/$$/fd . You could look at the 1 and 2 files to see if they are to the same thing.

paul@paul-laptop:~/$ perl -e 'print "Pid: $$\n"; print `ls -l /proc/$$
+/fd`'
Pid: 391
total 8
lrwx------ 1 paul paul 64 2007-03-06 09:34 0 -> /dev/pts/1
lrwx------ 1 paul paul 64 2007-03-06 09:34 1 -> /dev/pts/1
lrwx------ 1 paul paul 64 2007-03-06 09:34 2 -> /dev/pts/1
lr-x------ 1 paul paul 64 2007-03-06 09:34 3 -> pipe:[162460]
l-wx------ 1 paul paul 64 2007-03-06 09:34 4 -> pipe:[162460]
lr-x------ 1 paul paul 64 2007-03-06 09:34 5 -> pipe:[162461]
lr-x------ 1 paul paul 64 2007-03-06 09:34 6 -> inotify
l-wx------ 1 paul paul 64 2007-03-06 09:34 7 -> pipe:[162461]
paul@paul-laptop:~/$ perl -e 'print "Pid: $$\n"; print `ls -l /proc/$$
+/fd`' 2>&1
Pid: 393
total 5
lrwx------ 1 paul paul 64 2007-03-06 09:34 0 -> /dev/pts/1
lrwx------ 1 paul paul 64 2007-03-06 09:34 1 -> /dev/pts/1
lrwx------ 1 paul paul 64 2007-03-06 09:34 2 -> /dev/pts/1
lr-x------ 1 paul paul 64 2007-03-06 09:34 3 -> pipe:[162483]
lr-x------ 1 paul paul 64 2007-03-06 09:34 6 -> inotify
paul@paul-laptop:~/$ perl -e 'print "Pid: $$\n"; print `ls -l /proc/$$
+/fd`' 2>/dev/null
Pid: 395
total 8
lrwx------ 1 paul paul 64 2007-03-06 09:34 0 -> /dev/pts/1
lrwx------ 1 paul paul 64 2007-03-06 09:34 1 -> /dev/pts/1
l-wx------ 1 paul paul 64 2007-03-06 09:34 2 -> /dev/null
lr-x------ 1 paul paul 64 2007-03-06 09:34 3 -> pipe:[162501]
l-wx------ 1 paul paul 64 2007-03-06 09:34 4 -> pipe:[162501]
lr-x------ 1 paul paul 64 2007-03-06 09:34 5 -> pipe:[162502]
lr-x------ 1 paul paul 64 2007-03-06 09:34 6 -> inotify
l-wx------ 1 paul paul 64 2007-03-06 09:34 7 -> pipe:[162502]
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