From 565572077d89bb902710f22fc0e2dadeb9670038 Mon Sep 17 00:00:00 2001 From: EuAndreh Date: Fri, 2 Dec 2022 20:47:59 -0300 Subject: bin/free-port: Add new working utility --- bin/free-port | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100755 bin/free-port diff --git a/bin/free-port b/bin/free-port new file mode 100755 index 0000000..2476b4b --- /dev/null +++ b/bin/free-port @@ -0,0 +1,73 @@ +#!/bin/sh +set -eu + + +usage() { + cat <<-'EOF' + Usage: + free-port + free-port -h + EOF +} + +help() { + cat <<-'EOF' + + + Options: + -h, --help show this message + + + Returns a free TCP port. + + + Examples: + + Get a port for a command: + + $ cmd -p `free-port` + EOF +} + + +for flag in "$@"; do + case "$flag" in + --) + break + ;; + --help) + usage + help + exit + ;; + *) + ;; + esac +done + +while getopts 'h' flag; do + case "$flag" in + h) + usage + help + exit + ;; + *) + usage >&2 + exit 2 + ;; + esac +done +shift $((OPTIND - 1)) + + +PORT=1024 + +while true; do + if ! lsof -s TCP:LISTEN -i ":$PORT" >/dev/null; then + break + fi + PORT=$((PORT + 1)) +done + +echo "$PORT" -- cgit v1.2.3