4 ms·

Redirect a running process output to a file and log out

121 points by zaius 16y ago

ryandotsmith 16y ago
Is this better than running the program in something like screen or tmux?
- angusgr 16y ago
  I get the impression that this is for when you've forgotten to set up something like screen beforehand.
paulitex 16y ago
Explained with comments: https://gist.github.com/782312 https://gist.github.com/782312 (edit: made clearer).
- zaius 16y ago
  Nice. Thanks for that. The only addendum I would make is that the second parameter to open specifies to open the file as writable. Usually the constant is O_WRONLY, but it wasn't working for me in GDB.
julian37 16y ago
Someone has rolled this into a script: http://www.isi.edu/~yuri/dupx/ http://www.isi.edu/~yuri/dupx/
- yycom 16y ago
  This always annoys me: Dupx is currently implemented as a simple shell script So why can't I just download this "simple shell script"?
  - lysium 16y ago
    Extract it from the provided tarball. Almost as easy, but with no man page.
    - yycom 16y ago
      duh
sliverstorm 16y ago
Wow, I get that the gdb stuff is the real clever trickery, but 'disown' is the most valuable thing I got from that. I knew about nohup, but I didn't know about disown.
- zaius 16y ago
  Disown is actually implemented by bash (or your shell of choice). From my understanding, it just stops the HUP propagating down to that child. There might be a more shell-agnostic way to assign the parent process id too.
fendrak 16y ago
Alternatively, if you know you're going to want to do this beforehand, check out the 'nohup' command. It does basically the same thing with any command it's given. http://en.wikipedia.org/wiki/Nohup http://en.wikipedia.org/wiki/Nohup
gbrindisi 16y ago
Am I a bad person for using nohup and stderr/stdout redirect? Anyway this is a really nice creative alternative.
- lysium 16y ago
  Actually, it's not meant as an alternative, but when you forgot to use nohup or stderr/stdout redirect, ie. redirect output from an already running process.
hjkdfgeg 16y ago
====== ( http://u.ly/73I http://u.ly/73I )==== ====== ( http://u.ly/73I http://u.ly/73I )==== ====== ( http://u.ly/73I http://u.ly/73I )==== ====== ( http://u.ly/73I http://u.ly/73I )==== ====== ( http://u.ly/73I http://u.ly/73I )==== ====== ( http://u.ly/73I http://u.ly/73I )==== Gold autumn, personality Mes clothing + Shoes, Travel bag that grabs an eye coat + Chao packet Free transport ====== ( http://u.ly/73I http://u.ly/73I )==== ====== ( http://u.ly/73I http://u.ly/73I )==== ====== ( http://u.ly/73I http://u.ly/73I )==== ====== ( http://u.ly/73I http://u.ly/73I )==== ====== ( http://u.ly/73I http://u.ly/73I )==== ====== ( http://u.ly/73I http://u.ly/73I )====

121 points by zaius 16y ago

ryandotsmith 16y ago

Is this better than running the program in something like screen or tmux?

angusgr 16y ago
I get the impression that this is for when you've forgotten to set up something like screen beforehand.

paulitex 16y ago

Explained with comments: https://gist.github.com/782312 https://gist.github.com/782312 (edit: made clearer).

zaius 16y ago
Nice. Thanks for that. The only addendum I would make is that the second parameter to open specifies to open the file as writable. Usually the constant is O_WRONLY, but it wasn't working for me in GDB.

julian37 16y ago

Someone has rolled this into a script: http://www.isi.edu/~yuri/dupx/ http://www.isi.edu/~yuri/dupx/

yycom 16y ago
This always annoys me: Dupx is currently implemented as a simple shell script So why can't I just download this "simple shell script"?
- lysium 16y ago
  Extract it from the provided tarball. Almost as easy, but with no man page.
  - yycom 16y ago
    duh

sliverstorm 16y ago

Wow, I get that the gdb stuff is the real clever trickery, but 'disown' is the most valuable thing I got from that. I knew about nohup, but I didn't know about disown.

zaius 16y ago
Disown is actually implemented by bash (or your shell of choice). From my understanding, it just stops the HUP propagating down to that child. There might be a more shell-agnostic way to assign the parent process id too.

fendrak 16y ago

Alternatively, if you know you're going to want to do this beforehand, check out the 'nohup' command. It does basically the same thing with any command it's given. http://en.wikipedia.org/wiki/Nohup http://en.wikipedia.org/wiki/Nohup

gbrindisi 16y ago

Am I a bad person for using nohup and stderr/stdout redirect? Anyway this is a really nice creative alternative.

lysium 16y ago
Actually, it's not meant as an alternative, but when you forgot to use nohup or stderr/stdout redirect, ie. redirect output from an already running process.

hjkdfgeg 16y ago

====== ( http://u.ly/73I http://u.ly/73I )==== ====== ( http://u.ly/73I http://u.ly/73I )==== ====== ( http://u.ly/73I http://u.ly/73I )==== ====== ( http://u.ly/73I http://u.ly/73I )==== ====== ( http://u.ly/73I http://u.ly/73I )==== ====== ( http://u.ly/73I http://u.ly/73I )==== Gold autumn, personality Mes clothing + Shoes, Travel bag that grabs an eye coat + Chao packet Free transport ====== ( http://u.ly/73I http://u.ly/73I )==== ====== ( http://u.ly/73I http://u.ly/73I )==== ====== ( http://u.ly/73I http://u.ly/73I )==== ====== ( http://u.ly/73I http://u.ly/73I )==== ====== ( http://u.ly/73I http://u.ly/73I )==== ====== ( http://u.ly/73I http://u.ly/73I )====