https://github.com/fhofherr/hazcld

Check if a process has a certain child
https://github.com/fhofherr/hazcld

golang linux neovim tmux vim

Last synced: 3 days ago
JSON representation

Check if a process has a certain child

• Host: GitHub
• URL: https://github.com/fhofherr/hazcld
• Owner: fhofherr
• License: mit
• Created: 2021-02-07T14:55:53.000Z (over 3 years ago)
• Default Branch: main
• Last Pushed: 2021-02-07T15:15:28.000Z (over 3 years ago)
• Last Synced: 2024-04-16T03:17:09.837Z (6 months ago)
• Topics: golang, linux, neovim, tmux, vim
• Language: Go
• Homepage:
• Size: 5.86 KB
• Stars: 0
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

README

        
# hazcld - Check if a process has a certain child

`hazcld` is a Linux utility that given a process ID checks if the

corresponding process has a child process with the name matching the

passed regex.

Some tools require this information to determine how to process user

interaction.

[`vim-tmux-navigator`](https://github.com/christoomey/vim-tmux-navigator)

uses the

[following](https://github.com/christoomey/vim-tmux-navigator/blob/6a1e58c3ca3bc7acca36c90521b3dfae83b2a602/vim-tmux-navigator.tmux#L5)

to determine if a tmux pane runs `vim`:

    is_vim="ps -o state= -o comm= -t '#{pane_tty}' \

        | grep -iqE '^[^TXZ ]+ +(\\S+\\/)?g?(view|n?vim?x?)(diff)?$'"

This however breaks if the pane executes `vim` inside a `poetry shell

session`.

The following shell script would to the trick, but is rather slow:

```bash

#!/usr/bin/env bash

PATTERN="[[:space:]]*g?(view|n?vim?x?)(diff)?"

function find_vim() {

    local pid

    pid="$1"

    while [[ -n "$pid" ]]; do

        read -r pid cmd <<<"$(command ps --ppid "$pid" -o pid= -o comm=)"

        if [[ "$cmd" =~ $PATTERN ]]; then

            return 0

        fi

    done

    return 1

}

find_vim "$1"

```

This is an attempt to generalize the above script and make it faster by

reducing the amount of calls to `ps`.

A short try with the initial draft version looks promising. Please note

that this was not a properly planned benchmark. It mainly served to play

around a little with

[`hyperfine`](https://github.com/sharkdp/hyperfine):

| Command | Mean [ms] | Min [ms] | Max [ms] | Relative |

|:---|---:|---:|---:|---:|

| `./scripts/tmux-pane-runs-vim 2210` | 22.6 ± 1.2 | 21.1 | 26.9 | 5.18 ± 0.76 |

| `./bin/hazcld '\s*g?(view\|n?vim?x?)(diff)?' 2210` | 4.4 ± 0.6 | 3.6 | 6.6 | 1.00 |

Above table shows the output of

    hyperfine --export-markdown results.md \

              --warmup 10 \

              "./scripts/tmux-pane-runs-vim 2210" \

              "./bin/hazcld '\s*g?(view|n?vim?x?)(diff)?' 2210"

## Installation

The package can be installed using `go get`:

    go get github.com/fhofherr/hazcld

## Usage

Call `hazcld` using a [Go regular

expression](https://pkg.go.dev/regexp/syntax) matching the command the

child process you are interested in is executing and the process ID of a

parent process.

    hazcld '\s*g?(view|n?vim?x?)(diff)?' 2210

### Tmux

This repository contains a `hazcld_vim.tmux` script which can be used as

a [TPM](https://github.com/tmux-plugins/tpm) tmux plugin.

Add the following line to your `tmux.conf` and install the

`christoomey/vim-tmux-navigator` vim plugin.

    set -g @plugin 'fhofherr/hazcld'

## License

Copyright © 2021 Ferdinand Hofherr

Distributed under the MIT License.