netstat_cmdline

#!/bin/bash
#
# based on https://superuser.com/a/1079629
# consult that URL for a list of limitation
# that this script inherits
#
# I'm at home at https://github.com/tpo/little_shell_scripts

help() {
   echo 'usage: netstat_cmdline [netstat_options]*'
   echo '       netstat_cmdline --help'
   echo
   echo '    netstat_cmdline will call netstat and replace'
   echo '    the program name with the full command line'
   echo
   echo '    See `netstat --help` for all possible options'
   echo
   echo '    Note: netstat_cmdline works, but is slow and is'
   echo "          a hack (see its source code). It'd be"
   echo '          better to add a respective option to'
   echo '          netstat itself. Or to use `ss`, whose'
   echo '          output seems to be more robust to parse.'
   echo
   exit 1
}

[ "$1" == "--help" ] && help

set -e          # stop on error
set -u          # stop on undefined variable
set -o pipefail # stop part of pipeline failing

netstat "$@" -p | while IPS= read -r line;
  do
     pid="$( sed -En 's/^.*( [0-9]+)\/[^ ]*.*/\1/gp' <<< "$line" )"
     if [ "$pid" != "" ]; then
       cmdline="$(ps -p $pid -o cmd=)"
       line_start="$( sed -En 's/^(.* [0-9]+)\/[^ ]*.*/\1/gp' <<< "$line" )"
       line_end="$(   sed -En 's/^.* [0-9]+\/[^ ]*(.*)/\1/gp' <<< "$line" )"
       echo "$line_start#$cmdline $line_end"
     else
       echo "$line"
     fi
  done