Screenshot & Post-process

screenshot-and-postprocess.sh

#!/bin/bash
set -eu -o noclobber
outfile_format='Screenshot %(%F %T)T'
imgext=png
screenshot='gnome-screenshot -f'
postprocessor=gimp

# Discover user picture directory
user_dirs="${XDG_CONFIG_HOME:-"$HOME/.config"}/user-dirs.dirs"
[ ! -e "$user_dirs" ] || source "$user_dirs"

outdir="${XDG_PICTURES_DIR:-"$HOME/Pictures"}"
[ -e "$outdir" ] || mkdir -p -- "$outdir"

# Generate unique destination file name
touch_noclobber() { { : > "$1"; } 2>&-; }

printf -v outfile "%s/$outfile_format" "$outdir" -1
if ! touch_noclobber "$outfile.$imgext"; then
	declare -i i=1
	while ! touch_noclobber "$outfile.$i.$imgext"; do
		i=$(($i + 1))
	done
	outfile+=".$i"
fi
outfile+=".$imgext"
trap 'rm -f -- "$outfile"' EXIT

# Take and process screenshot
$screenshot "$outfile" "$@"
trap - EXIT
$postprocessor "$outfile"