Dupx

Dupx

Dupx is a simple *nix utility to redirect standard output/input/error of an already running process.

Motivation

I've often found myself in a situation where a process I started on a remote system via SSH takes much longer than I had anticipated. I need to break the SSH connection, but if I do so, the process will die if it tries to write something on stdout/error of a broken pipe. I wish I could suspend the process with ^Z and then do a

    bg %1 >/tmp/stdout 2>/tmp/stderr 
Unfortunately this will not work (in shells I know).

Output redirection of a running process
If you're familiar with dup(2) *nix system call, you know that if you issue it from the process space
to an open file, you can remap any file descriptor to a new file and all subsequent calls to read/write(2)
will read/write from/to the file.  Thus the simple idea behind dupx is to use gdb to attach to the
process and then do a dup(2) call on its file descriptors.

Implementation
Dupx is currently implemented as a simple shell script that drives
GDB.

Compatibility
Dupx has been tested on Fedora systems.

Files and downloads

    
First, you might want to look at the dupx man page.
    
Source tarball: dupx-0.1.tar.gz.
    
Source rpm: dupx-0.1-1.src.rpm.
    
Noarch rpm: dupx-0.1-1.noarch.rpm.






Last Modified: Mon Aug 16 15:46:00 PDT 2010