audacious-songchange

#!/bin/sh
VERSION="1.0.20181101"

help() { cat <</help
Executes a command file and writes a blank one in its place.
Usage: audacious-songchange [CURRENT-SONG]

Add this with audacious in Settings, Plugins, General, Song Change, starting:
  audacious-songchange "%T"

Set keybindings to run commands like:
  audacious-songchange --queue-stop
(this will stop audacious after the current song finishes)

audacious-songchange $VERSION, Copyright 2003+ by Adam Katz, GPLv2+
Learn more at https://github.com/adamhotep/media-scripts
/help
  exit
}

version() { cat <</version
audacious-songchange $VERSION
(originally called xmms-songchange)
Copyright (C) 2003+  Adam Katz
License GPLv2+: GNU GPL version 2 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
/version
  exit
}

license() { cat <</license
Copyright (C) 2010+  Adam Katz
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
/license
  exit
}

# true only when we have all given commands
we_have() {
  command -v "$@" >/dev/null 2>&1
}

# exit with given error(s)
die() {
  for text in "$@"; do
    echo "$text" >&2
  done
  exit 2
}

for DIR in .config/audacious .config/beep /.beep .config/xmms2 .xmms2 .xmms; do
  DIR="$HOME/$DIR"
  if [ -d "$DIR" ]; then break; fi
done

if [ ! -d "$DIR" ] || [ ! -w "$DIR" ]; then
  die "Cannot locate audacious/beep/xmms2/xmms directory, aborting"
fi

CMD="${DIR##*/}"	# command taken from DIR name
for CMD in "$CMD" "${CMD%2}" "${CMD}2"; do
  if we_have "$CMD"; then
    break
  fi
done

if ! we_have "$CMD"; then
  die "Cannot locate audacious/beem/xmms2/xmms command, aborting"
fi


CMDFILE="$DIR/command"

while getopts c:hLqV-: OPT; do
  case "$OPT" in
    (c) 	CMDFILE="$OPTARG" ;;
    (h) 	help ;;
    (L) 	license ;;
    (q) 	QUEUE_STOP=1 ;;
    (V) 	version ;;
    (-) case "$OPTARG" in
      (help)	help ;;
      (license)	license ;;
      ([cq]ue*)	QUEUE_STOP=1 ;;
      (version)	version ;;
      ('')	break ;;
      (*)	die "Illegal option --$OPTARG" "Try --help" ;;
     esac ;;
    (\?) 	die "Try --help" ;;
  esac
done
shift $((OPTIND-1))

# create the file if it's missing
if [ ! -e "$CMDFILE" ]; then
  touch "$CMDFILE"
fi

# make executable if not already (only if we own the file)
if [ ! -x "$CMDFILE" ] && [ -O "$CMDFILE" ]; then
  chmod +x "$CMDFILE"
fi

if [ 1 = "$QUEUE_STOP" ]; then
  echo "$CMD --stop" >> "$CMDFILE"
  exit
fi

if [ -s "$CMDFILE" ]; then
  cp -p "$CMDFILE" "${CMDFILE}-prev"
fi

# run script
[ -x "$CMDFILE" ] && "$CMDFILE" || echo 'problem running script' >&2

# erase script and place the following information there instead:
echo "# now playing: $*
# $(date)
####################################################################
# This is an auto-generated file and will be overwritten after use.
# The following will be run once the above song ends:
" >"$CMDFILE"