I am using trying to write to /dev/stdout as user "esc" via a script - which produces the error msg - ** Unable to open file: /dev/stdout. Errno=13.

When I run this as su root - I can run the script without error.

Any idea why i cannot write to /dev/stdout? I have chmoded the dirs to 666.

Why are you trying to write to the device directly? I suggest you use "echo" for that kind of thing if you can.

The script calls a program that uses the /dev/stdout and stdin. I am moving from SCO Open server 5 to Linux Red Hat ES 4.0. The script runs fine in SCO - but I do not see why there is an issue with the stdout and stdin with Linux.

Hmm... It seems to me that writing to stdout device directly in is a SCO-dependent hack of some sort. Try creating a copy that uses echo instead.

Or, create a group (maybe called output or something) and change the group of /dev/stdout to this group. Then, make it group writeable, and add the user to this group. You can then use your existing code.

i see that on the SCO box stdout, stdin, stderr have the following attributes:

crw-rw-rw- 2 root root 24, 1 Feb 17 2001 stdout
crw-rw-rw- 2 root root 24, 0 Feb 17 2001 stdin
crw-rw-rw- 2 root root 24, 2 Feb 17 2001 stderr

but the Linux box stdout, stdin, stderr have the following attributes:

lrwxrwxrwx 1 root root 15 Sep 1 05:34 stdin -> /proc/self/fd/0
lrwxrwxrwx 1 root root 15 Sep 1 05:34 stdout -> /proc/self/fd/1
lrwxrwxrwx 1 root root 15 Sep 1 05:34 stderr -> /proc/self/fd/2

could there be an issue with the type of file (character device vs. linked file)?

With the linux box, stdin, stdout, and stderr have their own per-process definitions as fds. Is this program run setuid or anything alone those lines? Any user should be able to write to file descriptors they control.