Thelm

Selection narrowing tool for the terminal. The basic idea is the adapted from Emacs-helm.

To see thelm in action, the following use cases contain animations:

Running ag or git-grep continuously
Insert a command to prompt from history
Choose directory where to jump from directory stack

Installation

$ go get github.com/kopoli/thelm

Alternatively you can download one of the pre-compiled releases.

Usage

Basic operation is the following:

Reads data from:
- Running given command repeatedly.
- A pipe.
- A file.
User is able to select a line visually with a termbox-go user interface.
The line is printed out to stdout.

Command line

$ ./thelm --help

Usage: ./thelm [OPTIONS] [-- ARG...]

Helm for terminal

Arguments:
  ARG                         Command to be run

Options:
  -v, --version               Show the version and exit
  -f, --filter                Start filtering after running command.
  -d, --default               The default argument that will be printed out if aborted.
  -i, --hide-initial          Hide command given at the command line.
  -s, --single-arg            Regard input given in the UI as a single argument to the program.
  -r, --relaxed-regexp        Regard input as a relaxed regexp. Implies --single-arg.
  -t, --title                 Title string in UI. (default "./thelm")
  -F, --file                  The file which will be read instead of running a command.
  -P, --pipe                  The data will be read through a pipe.
      --licenses              Show licenses of ./thelm.
      --cpu-profile-file      The CPU profile would be saved to this file.
      --memory-profile-file   The Memory profile would be saved to this file.

Concepts:

Filtering means that the current input can be filtered/narrowed down grep -style. This can be toggled with a key binding. If the -f flag is given, the data is read once (or a command is run once) and then it is filtered within thelm.
Default argument is what is printed out if user aborts out of the UI. If this is not supplied, nothing is printed.
Hiding initial arguments means that the user can give a part of the command from the command line and the rest in the UI. See for an example in Running ag or git-grep continuously.
Single argument is used when the part of the command line given in the UI is wanted to be given to the called program as a single argument. Without this, whitespace delimited fields are interpret as separate arguments.
Reading from a file is invoked with the -F flag.
Reading from a pipe is invoked with the -P flag.

Key bindings within the narrowing UI

Key	Function
ESC	Abort.
C-g	Abort.
up C-p	Select previous item.
down C-n	Select next item.
pgup	Move focus backward a screenful.
pgdown	Move focus forward a screenful.
RET	Terminate UI and print highlighted line to stdout.
C-f	Toggle filtering.

Use cases

Insert a command to prompt from history

This is comparable to the "C-r" binding in bash and zsh. I have only zsh configuration for this setup. It can be found here. This is configured to "Meta-," keybinding by default.

Choose directory where to jump from directory stack

The ZSH configuration is in here. It uses "Meta-." key binding by default.

Running ag or git-grep continuously

$ ./thelm --hide-initial --single-arg ag

This is marginally useful from the terminal. Obviously I prefer helm-grepint for Emacs.

License

MIT license