GopherProxy

	Title: Implement a «Command not found» handler in OpenBSD
	Author: Solène
	Date: 09 March 2021
	Tags: openbsd
	Description:

	# Introduction

	On many Linux systems, there is a special program run by the shell
	(configured by default) that will tell you which package provide a
	command you tried to run but is not available in $PATH. Let's do the
	same for OpenBSD!

	# Prerequisites

	We will need to install the package pkglocate to find binaries.

	```shell command as root
	# pkg_add pkglocate
	```

	We will also need a file /usr/local/bin/command-not-found executable
	with this content:

	```shell script
	#!/bin/sh

	CMD="$1"

	RESULT=$(pkglocate /bin/${CMD} /sbin/${CMD} \| cut -d ':' -f 1)

	if [ -n "$RESULT" ]
	then
	echo "The following package(s) contain program ${CMD}"
	for result in $RESULT
	do
	echo " - $result"
	done
	else
	echo "pkglocate didn't find a package providing program ${CMD}"
	fi
	```

	# Configuration

	Now, we need to configure the shell to run this command when it detects
	an error corresponding to an unknown command. This is possible with
	bash, zsh or fish at least.


	## Bash configuration

	Let's go with bash, add this to your bash configuration file

	```bash script
	command_not_found_handle()
	{
	/usr/local/bin/command-not-found "$1"
	}
	```

	## Fish configuration

	```fish shell script
	function fish_command_not_found
	/usr/local/bin/command-not-found $argv[1]
	end
	```

	## ZSH configuration

	```zsh shell script
	function command_not_found_handler()
	{
	/usr/local/bin/command-not-found "$1"
	}
	```

	# Trying it

	Now that you configured your shell correctly, if you run a command in
	your shell that isn't available in your PATH, you may have either a
	success with a list of packages giving the command or that the command
	can't be found in any package (unlucky).

	This is a successful output that found the program we were trying to
	run.

	```Success output
	$ pup
	The following package(s) contain program pup
	- pup-0.4.0p0
	```

	This is a result showing that no package found a program named "steam".

	```Unsuccessful output
	$ steam
	pkglocate didn't find a package providing program steam
	```