I am trying to kill a process in the command line for a specific port in Ubuntu. If I run this command, I get the port: sudo lsof -t -i:9001 so...now I want to run: sudo kill 'sudo lsof -t -i:9001... More on stackoverflow.com

I wrote this up and got distracted for the last few hours... I really, really like the simplicity! At the risk of ruining that, however, I wonder if it may be useful/wise to have a confirmation option like rm's -i? You may also like to check whether the user has the ability to kill the target proc and if not, look at launching sudo. Or just outright restrict it to root/sudo only. #!/bin/bash set -euo pipefail It's been a while since I've had to say this: Standard Warning about The Unofficial Strict Mode. readonly os=$(uname) https://www.shellcheck.net/wiki/SC2155 You may also like to look at $OSTYPE kill_port() { local port=$1 https://www.shellcheck.net/wiki/SC2155 ... probably.... You may like to consider something like port="${1:?No port defined}" to have a degree of auto-failure. It's not strictly necessary in this case, but a good habit to get into nonetheless. # Validate the port number if ! [[ "$port" =~ ^[0-9]{1,5}$ && "$port" -ge 0 && "$port" -le 65535 ]]; then echo "Invalid port number" exit 1 fi There's a bit going on here. Firstly, I would split this out into separate checks like this: printf -- '%d' "${port}" >/dev/null 2>&1 || { printf -- '%s\n' "Given port is not an integer" >&2 exit 1 } (( port > 0 && port <= 65535 )) || { printf -- '%s\n' "Given port must be between 1 and 65535" >&2 exit 1 } If the script got much bigger, you'd want to implement a die() function, so those would look more like printf -- '%d' "${port}" >/dev/null 2>&1 || die "Given port is not an integer" (( port > 0 && port <= 65535 )) || die "Given port must be between 1 and 65535" Note that I use printf. echo is a portability mess and POSIX specifies that you should use printf for that reason - they decided that echo was unfixable. Fun fact: echo in Apple's default bash is different from echo in the same version of bash on Linux. When you use echo, what you're doing is inflicting unpredictable behaviour on consumers of your code. Note also that these are error messages, so we send them to stderr. # Check if port is in use if ! type lsof >/dev/null 2>&1 || ! lsof -Pi :"$port" -sTCP:LISTEN -t >/dev/null; then echo "Port $port is not in use" exit 1 fi The more common way to check if a command exists is command -v rather than type/which/hash/-x # Kill the process if [ "$os" == "Darwin" ]; then # macOS lsof -ti tcp:"$port" | xargs kill else # Linux fuser -k "$port"/tcp fi == is best reserved for arithmetic contexts IMHO, and within single square brackets it's not a specified behaviour. Use = for string comparisons in [[]] and == for arithmetic comparisons in (()). Generally speaking. Consider a case statement instead. You can see examples of $OSTYPE in a case statement here Linux often has lsof too, you may also like to look at netstat and/or ss echo "Process on port $port killed" } # Check if port is provided if [ $# -ne 1 ]; then echo "usage: killport " exit 1 fi I would put this right towards the top of the script. You want a script to fail fast, fail early: so fail out before declaring any vars, functions etc. kill_port "$1" exit 0 Nice. More on reddit.com

UNIX isn't Linux, and (most) Linux isn't UNIX. And even on Linux, netstat (highly deprecated) and lsof may not be installed. For Linux, ss has superseded netstat, so ss may be used. On Linux, if fuser is present, that may also be used, e.g.: # fuser -n tcp 22 More on reddit.com

I was wondering, is there any way to kill a process that is running on a specific IP and port on Ubuntu 14.04 on a local IP and port? Preferably, this would be in one command, but if not, a bash sc... More on unix.stackexchange.com