forky a utility for managing multiple commands in the background.

forky

#!/bin/bash

FILE="forky.state"
SESSION_PREFIX="forky"

function print_help {
  echo "forky v0.1.0"
  echo "A utility for managing multiple commands in the background."
  echo ""
  echo "Usage:"
  echo "  $0 cmds=\"cmd0 [args]\",\"cmd1 [args]\" dirs=\"dir0\",\"dir1\""
  echo "  $0 start [id]"
  echo "  $0 stop [id]"
  echo "  $0 reset [id]"
  echo "  $0 list"
  echo "  $0 open <id>"
  echo "  $0 save <id> [output_file]"
  echo "  $0 help"
  echo ""
  echo "Options:"
  echo "  cmds:    A comma-separated list of commands to run in the background."
  echo "  dirs:        A comma-separated list of directories where each command should be run. Must have the same number of items as commands."
  echo "  start:       Starts the previously saved commands if available."
  echo "  stop:        Kills the tmux sessions."
  echo "  reset:       resets the previously saved commands."
  echo "  list:        Lists the tmux sessions."
  echo "  open:        Attaches to the tmux session for the given command ID."
  echo "  save:        Save the tmux session output to a given file or if not specified print to console."
  echo "  help:        Prints this help message."
}

function load_state {
  if [ ! -f "$FILE" ]; then
    echo "Error: $FILE not found."
    exit 1
  fi
  while IFS= read -r line; do
    key="${line%%:*}"
    value="${line#*: }"
    if [[ $key == cmd* ]]; then
      CMDS+=("$value")
    elif [[ $key == dir* ]]; then
      DIRS+=("$value")
    fi
  done < $FILE
}

function validate_id {
  if [ -n "$ID" ] && ( [ "$ID" -lt "0" ] || [ "$ID" -ge "${#CMDS[@]}" ] ); then
    echo "Error: Invalid ID. Must be in the range [0, ${#CMDS[@]})."
    exit 1
  fi
}

function run_commands {
  if [ "${#CMDS[@]}" -ne "${#DIRS[@]}" ]; then
    echo "Error: Number of commands does not match number of directories."
    exit 1
  fi
  TEMP_FILE=$(mktemp)
  for i in "${!CMDS[@]}"; do
    if [ -z "$ID" ] || [ "$ID" == "$i" ]; then
      CMD="${CMDS[$i]}"
      DIR="${DIRS[$i]}"
      SESSION_NAME="${SESSION_PREFIX}-cmd${i}"
      tmux new-session -d -s "$SESSION_NAME" "cd $DIR && $CMD; bash"
      if [ $? -ne 0 ]; then
        echo "Error: Failed to start tmux session for command $i."
        continue
      fi
      echo "cmd${i}: $CMD" >> $TEMP_FILE
      echo "dir${i}: $DIR" >> $TEMP_FILE
    fi
  done
  mv $TEMP_FILE $FILE
  echo "Commands executed in the background. tmux sessions created."
}

function stop_sessions {
  for i in "${!CMDS[@]}"; do
    if [ -z "$ID" ] || [ "$ID" == "$i" ]; then
      SESSION_NAME="${SESSION_PREFIX}-cmd${i}"
      tmux kill-session -t "$SESSION_NAME" 2>/dev/null
    fi
  done
  echo "tmux sessions killed."
}

function list_sessions {
  echo "id     session                            command"
  for i in "${!CMDS[@]}"; do
    SESSION_NAME="${SESSION_PREFIX}-cmd${i}"
    CMD="${CMDS[$i]}"
    printf "%-6s%-36s%s\\n" "$i" "$SESSION_NAME" "$CMD"
  done
}

function open_session {
  SESSION_NAME="${SESSION_PREFIX}-cmd$ID"
  tmux attach-session -t "$SESSION_NAME"
}

function save_session {
  SESSION_NAME="${SESSION_PREFIX}-cmd$ID"
  if [ -z "$ID" ]; then
    echo "Usage: $0 save <id> [output_file]"
    return
  fi
  if [ -z "$OUTPUT_FILE" ]; then
    tmux capture-pane -t "$SESSION_NAME" -p
    echo "Session ${SESSION_NAME} content printed to console."
  else
    tmux capture-pane -t "$SESSION_NAME" -p > "$OUTPUT_FILE"
    echo "Session ${SESSION_NAME} saved to $OUTPUT_FILE"
  fi
}


if [ "$1" == "help" ]; then
  print_help
elif [[ $1 == "cmds="* ]] && [[ $2 == "dirs="* ]]; then
  IFS=',' read -ra CMDS <<< "${1#cmds=}"
  IFS=',' read -ra DIRS <<< "${2#dirs=}"
  run_commands
elif [ "$1" == "stop" ] || [ "$1" == "start" ] || [ "$1" == "reset" ]; then
  if [ -f "$FILE" ]; then
    load_state
    ID="$2" # Optional command ID
    validate_id
    if [ "$1" == "stop" ]; then
      stop_sessions
    elif [ "$1" == "start" ]; then
      run_commands
    elif [ "$1" == "reset" ]; then
      $0 stop "$ID"
      $0 start "$ID"
    fi
  else
    echo "$FILE not found."
    exit 1
  fi
elif [ "$1" == "list" ]; then
  if [ -f "$FILE" ]; then
    load_state
    list_sessions
  else
    echo "$FILE not found."
  fi
elif [ "$1" == "open" ]; then
  if [ -f "$FILE" ]; then
    load_state
    ID="$2" # Command ID for the session to be opened
    open_session
  else
    echo "$FILE not found."
  fi
elif [ "$1" == "save" ]; then
  if [ -f "$FILE" ]; then
    load_state
    ID="$2"
    OUTPUT_FILE="$3"
    save_session
  else
    echo "$FILE not found."
  fi
else
  print_help
fi