Environment Variables and Pipes

Alternative to CallLua, CallLuaSilently messages that call Lua functions, there are Call0, CallSilently0, BashExec0, BashExecSilently0 messages that call shell commands.

Example: Simple file opener using xdg-open and $XPLR_FOCUS_PATH

xplr.config.modes.builtin.default.key_bindings.on_key["X"] = {
  help = "open",
  messages = {
    {
      BashExecSilently0 = [===[
        xdg-open "${XPLR_FOCUS_PATH:?}"
      ]===],
    },
  },
}

However, unlike the Lua functions, these shell commands have to read the useful information and send messages via environment variables and temporary files called "pipe"s. These environment variables and files are only available when a command is being executed.

Example: Using Environment Variables and Pipes

xplr.config.modes.builtin.default.key_bindings.on_key["space"] = {
  help = "ask name and greet",
  messages = {
    {
      BashExec0 = [===[
        echo "What's your name?"

        read name
        greeting="Hello $name!"
        message="$greeting You are inside $PWD"

        "$XPLR" -m 'LogSuccess: %q' "$message"
      ]===]
    }
  }
}

-- Now, when you press "space" in default mode, you will be prompted for your
-- name. Enter your name to receive a nice greeting and to know your location.

Visit the fzf integration tutorial for another example.

To see the environment variables and pipes, invoke the shell by typing :! in default mode and run the following command:

env | grep ^XPLR

You will see something like:

XPLR=xplr
XPLR_FOCUS_INDEX=0
XPLR_MODE=action to
XPLR_PIPE_SELECTION_OUT=/run/user/1000/xplr/session/122278/pipe/selection_out
XPLR_INPUT_BUFFER=
XPLR_PIPE_GLOBAL_HELP_MENU_OUT=/run/user/1000/xplr/session/122278/pipe/global_help_menu_out
XPLR_PID=122278
XPLR_PIPE_MSG_IN=/run/user/1000/xplr/session/122278/pipe/msg_in
XPLR_PIPE_LOGS_OUT=/run/user/1000/xplr/session/122278/pipe/logs_out
XPLR_PIPE_RESULT_OUT=/run/user/1000/xplr/session/122278/pipe/result_out
XPLR_PIPE_HISTORY_OUT=/run/user/1000/xplr/session/122278/pipe/history_out
XPLR_FOCUS_PATH=/home/sayanarijit/Documents/GitHub/xplr/docs/en/book
XPLR_SESSION_PATH=/run/user/1000/xplr/session/122278
XPLR_APP_VERSION=0.14.3
XPLR_PIPE_DIRECTORY_NODES_OUT=/run/user/1000/xplr/session/122278/pipe/directory_nodes_out

The environment variables starting with XPLR_PIPE_ are the temporary files called "pipe"s.

The other variables are single-line variables containing simple information:

XPLR
XPLR_APP_VERSION
XPLR_FOCUS_INDEX
XPLR_FOCUS_PATH
XPLR_INPUT_BUFFER
XPLR_INITIAL_PWD
XPLR_MODE
XPLR_PID
XPLR_SESSION_PATH
XPLR_VROOT

Environment variables

XPLR

The binary path of xplr command.

XPLR_APP_VERSION

Self-explanatory.

XPLR_FOCUS_INDEX

Contains the index of the currently focused item, as seen in column-renderer/index.

XPLR_FOCUS_PATH

Contains the full path of the currently focused node.

XPLR_INITIAL_PWD

The $PWD then xplr started.

XPLR_INPUT_BUFFER

The line currently in displaying in the xplr input buffer. For e.g. the search input while searching. See Reading Input.

XPLR_MODE

Contains the mode xplr is currently in, see modes.

XPLR_PID

Contains the process ID of the current xplr process.

XPLR_SESSION_PATH

Contains the current session path, like /tmp/runtime-"$USER"/xplr/session/"$XPLR_PID"/, you can find temporary files here, such as pipes.

XPLR_VROOT

Contains the path of current virtual root, is set.

Pipes

Input pipe

Currently there is only one input pipe.

XPLR_PIPE_MSG_IN

Output pipes

XPLR_PIPE_*_OUT are the output pipes that contain data which cannot be exposed directly via environment variables, like multi-line strings. These pipes can be accessed as plain text files located in $XPLR_SESSION_PATH.

Depending on the message (e.g. Call or Call0), each line will be separated by newline or null character (\n or \0).

XPLR_PIPE_SELECTION_OUT
XPLR_PIPE_GLOBAL_HELP_MENU_OUT
XPLR_PIPE_LOGS_OUT
XPLR_PIPE_RESULT_OUT
XPLR_PIPE_HISTORY_OUT
XPLR_PIPE_DIRECTORY_NODES_OUT

XPLR_PIPE_MSG_IN

Append new messages to this pipe in YAML (or JSON) syntax. These messages will be read and handled by xplr after the command execution.

Depending on the message (e.g. Call or Call0) you need to separate each message using newline or null character (\n or \0).

NOTE: Since version v0.20.0, it's recommended to avoid writing directly to this file, as safely escaping YAML strings is a lot of work. Use xplr -m / xplr --pipe-msg-in to pass messages to xplr in a safer way.

It uses jf syntax to safely convert an YAML template into a valid message.

Example: "$XPLR" -m 'ChangeDirectory: %q' "${HOME:?}"

xplr book