ir

#!/bin/bash

help_text=\
"NAME
	ir - create a temporary file structure and run a viewer
	
SYNOPSIS
	ir
	ir directory [directory ...]
	non_interactive_commands_pipeline | ir
	ir 'command'
	
DESCRIPTION
	Given a list of files and directories, create a directory structure
	in a temporary directory with links to the files and directories; ranger
	(or another viewer) is then run in the temporary directory.
	
ARGUMENTS
	With no arguments, ir runs 'fzf -m' to select files and directories.
	
	If given directories, 'fzf -m' is used to select from the directories.
	
	ir accepts the list of files on stdin, if you generate the file list
	via a pipeline, make sure no interactive command is used (IE: fzf).
	
	A user command to generate a list of files can be given to ir; the
	command can be interactive.
	
USER COMMAND
	The user command is given as an argument, quote the command to avoid
	shell interpolation.
	
	E.G.: ir 'find /home/directory/ -type f | fzf -m'
	
	You can add a macro in your initrc to do the wrapping:
		"\ei": '\C-a ir '\C-e'

LINKING DIRECTORIES
	If a directory is given in the file list, previously linked files in
	that directory are removed and the directory is linked.
	
	If you want sparsely populated directories, don't pass directories, the
	examples above use '-type -f' to filter out directories.
	
OPTIONS
	-h|--help	display this help text
	-d|--debug	display debug information, temporary directory is kept
	-v|--viewer=cmd	run the command after setting up the file structure
	--no_viewer	only create the structure
	-f|--flat	the files are linked to basename.dirname flattening the
			directory structure
	
ENVIRONMENT VARIABLES
	IR_DEBUG	see --debug
	IR_VIEWER	see --viewer
	IR_NO_VIEWER	see --no_viewer
	IR_FLAT		see --flat"

while :; do
	case $1 in
		-h|--help)
			echo "$help_text"
			exit 0 ;;
		-d|--debug)
			IR_DEBUG=1 ;;
		-v|--viewer)
			IR_VIEWER=$2 ; : ${IR_VIEWER:=ranger} ; shift ;;
		--no_viewer)
			IR_NO_VIEWER=1 ;;
		-f|--flat)
			IR_FLAT=1 ;;
		-?*)
			printf 'ir: Error: Unknown option: %s\n' "$1" >&2
			exit 1 ;;
		*)
			break
	esac
	shift
done

set -e

IR_VIEWER=${IR_VIEWER:-ranger}

td=/tmp/$(mktemp -d -u ir_XXXXXXXX)
mkdir -p "$td" &>/dev/null

t=$td/.ir_input

if [[ ! -t 0 ]] ; then
	[[ -n $IR_DEBUG ]] && echo ir: redirecting stdin to file list: $t
	cat > "$t"
	echo >> "$t"
elif [[ -z "$1" ]] ; then
	[[ -n $IR_DEBUG ]] && echo ir: redirecting command "'fzf -m'" to file list: $t
	fzf -m > "$t"
	d=$(pwd)/
elif [[ -d "$1" ]] ; then
	find $* | fzf -m > "$t"
else
	[[ -n $IR_DEBUG ]] && echo ir: redirecting command "'$*'" to file list: $t
	eval $* > "$t"
fi

exec 3< $t

while read f <&3 ; do
	if [[ -n $f ]] ; then
		
		f=${f%/}
		[[ -n $IR_DEBUG ]] && echo ir: linking "$d$f"
		
		[[ -d "$f" && -e "$td/$f" ]] && rm -rf "$td/$f"
		
		if [[ -z $IR_FLAT ]] ; then
			mkdir -p "$td/"$(dirname  "$f")
			ln -s "$d$f" "$td/$f"
		else
			destination="$td/"$(basename "$f").$(dirname "$f" | tr / _)
			ln -s "$d$f" "$destination"
		fi
	fi
done

[[ -z $IR_NO_VIEWER ]] && echo "$td" | parallel -X --tty "$IR_VIEWER"
[[ -z $IR_DEBUG ]] && rm -rf "$td"