Remaining number of open files in Linux

Question

ulimit -a tells me I have a limit of 1024 open files, which is the default on my distro. Is there a way to show how many of these are currently used, or how many are remaining?

Answer 1

This limit apply per process.

One way to get the number of open files per process would be on Linux or Solaris:

for i in /proc/*/fd
do
    [ -r $i ] && printf "%6d : %d\n" $(basename $(dirname $i)) $(ls $i | wc -l)
done