open file linux cheat sheet

open_files_linux_cheat_sheet.txt

# show the limits in place on the system 
ulimit -a

# system wide ulmits 
ulimit -Sn  # soft limit
ulimit -Hn  # hard limit

# list open files for all processes and sort them by how many files are open
for pid in /proc/[0-9]*; do echo "PID = $(basename $pid) : $(ls $pid/fd 2>/dev/null | wc -l) open files"; done | sort -n -k5,5

# list all open files (provided not to many
lsof | wc -l

# list open files outout blocking - may not provide accurate counts
lsof -b 2>&1 | wc -l