lsof | cut -f 1 -d ' ' | uniq -c | sort -rn | head -n 10

List open file descriptor count by PID

Useful for when you find the system runs out of file descriptors and you want to know why.
Sample Output
  32015 java
   2567 Passenger
   1630 ruby
   1470 rtorrent
   1316 ruby
   1014 ruby
    957 python2
    689 ruby
    510 deluged
    337 postgres

2014-11-12 09:16:19

These Might Interest You

  • taken from " What does it mean? The redirection operator n>&m makes file descriptor n to be a copy of file descriptor m. So, whe are: - Opening a new file descriptor, 3, that is a copy of file descriptor 1, the standard output; - Making file descriptor 1 a copy of file descriptor 2, the standard error output; - Making file descriptor 2 to be a copy of file descriptor 3 (the "backup" of the standard output) in a short: we swapped the standard output and the standard error output. "

    command 3>&1 1>&2 2>&3 | tee file
    hute37 · 2012-10-30 10:53:21 1
  • Ever needed to test firewalls but didn't have netcat, telnet or even FTP? Enter /dev/tcp, your new best friend. /dev/tcp/(hostname)/(port) is a bash builtin that bash can use to open connections to TCP and UDP ports. This one-liner opens a connection on a port to a server and lets you read and write to it from the terminal. How it works: First, exec sets up a redirect for /dev/tcp/$server/$port to file descriptor 5. Then, as per some excellent feedback from @flatcap, we launch a redirect from file descriptor 5 to STDOUT and send that to the background (which is what causes the PID to be printed when the commands are run), and then redirect STDIN to file descriptor 5 with the second cat. Finally, when the second cat dies (the connection is closed), we clean up the file descriptor with 'exec 5>&-'. It can be used to test FTP, HTTP, NTP, or can connect to netcat listening on a port (makes for a simple chat client!) Replace /tcp/ with /udp/ to use UDP instead.

    exec 5<>/dev/tcp/; cat <&5 & cat >&5; exec 5>&-
    tyzbit · 2015-07-30 21:12:38 9
  • the tee command does fine with file names, but not so much with file descriptors, such as &2 (stderr). This uses process redirection to tee to the specified descriptor. In the sample output, it's being used to tee to stderr, which is connected with the terminal, and to wc -l, which is also outputting to the terminal. The result is the output of bash --version followed by the linecount Show Sample Output

    tee >(cat - >&2)
    camocrazed · 2010-07-20 17:22:31 3
  • List all open files of all processes. . find /proc/*/fd Look through the /proc file descriptors . -xtype f list only symlinks to file . -printf "%l\n" print the symlink target . grep -P '^/(?!dev|proc|sys)' ignore files from /dev /proc or /sys . sort | uniq -c | sort -n count the results . Many processes will create and immediately delete temporary files. These can the filtered out by adding: ... | grep -v " (deleted)$" | ... Show Sample Output

    find /proc/*/fd -xtype f -printf "%l\n" | grep -P '^/(?!dev|proc|sys)' | sort | uniq -c | sort -n
    flatcap · 2015-08-18 17:58:21 0
  • Add permanent line numbers to a file without creating a temp file. The rm command deletes file10 while the nl command works on the open file descriptor of file10 which it outputs into a new file again named file10. The new file10 will now be numbered in the same directory with the same file name and content as before, but it will in fact be a new file, using (ls -i) to show its inode number will prove this.

    { rm -f file10 && nl > file10; } < file10
    zlemini · 2010-04-08 21:08:23 4

  • 0
    users | xargs -n1 echo | sort | uniq -c
    michaelmior · 2011-01-05 19:05:05 0

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

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