1 files changed, 120 insertions, 0 deletions
diff --git a/dwmswallow b/dwmswallow
new file mode 100644
index 0000000..eaab3bb
--- /dev/null
+++ b/dwmswallow
@@ -0,0 +1,120 @@
+#!/usr/bin/env sh
+
+# Separator and command prefix, as defined in dwm.c:fakesignal()
+SEP='###'
+PREFIX='#!'
+
+# Asserts that all arguments are valid X11 window IDs, i.e. positive integers.
+# For the purpose of this script 0 is declared invalid.
+is_winid() {
+	while :; do
+		# Given input incompatible to %d, some implementations of printf return
+		# an error while others silently evaluate the expression to 0.
+		if ! wid=$(printf '%d' "$1" 2>/dev/null) || [ "$wid" -le 0 ]; then
+			return 1
+		fi
+
+		[ -n "$2" ] && shift || break
+	done
+}
+
+# Prints usage help. If "$1" is provided, function exits script after
+# execution.
+usage() {
+	[ -t 1 ] && myprintf=printf || myprintf=true
+	msg="$(cat <<-EOF
+	dwm window swallowing command-line interface. Usage:
+
+	  $($myprintf "\033[1m")dwmswallow $($myprintf "\033[3m")SWALLOWER [-c CLASS] [-i INSTANCE] [-t TITLE]$($myprintf "\033[0m")
+	    Register window $($myprintf "\033[3m")SWALLOWER$($myprintf "\033[0m") to swallow the next future window whose attributes
+	    match the $($myprintf "\033[3m")CLASS$($myprintf "\033[0m") name, $($myprintf "\033[3m")INSTANCE$($myprintf "\033[0m") name and window $($myprintf "\033[3m")TITLE$($myprintf "\033[0m") filters using basic
+	    string-matching. An omitted filter will match anything.
+
+	  $($myprintf "\033[1m")dwmswallow $($myprintf "\033[3m")SWALLOWER -d$($myprintf "\033[0m")
+	    Deregister queued swallow for window $($myprintf "\033[3m")SWALLOWER$($myprintf "\033[0m"). Inverse of above signature.
+
+	  $($myprintf "\033[1m")dwmswallow $($myprintf "\033[3m")SWALLOWER SWALLOWEE$($myprintf "\033[0m")
+	    Perform immediate swallow of window $($myprintf "\033[3m")SWALLOWEE$($myprintf "\033[0m") by window $($myprintf "\033[3m")SWALLOWER$($myprintf "\033[0m").
+
+	  $($myprintf "\033[1m")dwmswallow $($myprintf "\033[3m")SWALLOWEE -s$($myprintf "\033[0m")
+	    Stop swallow of window $($myprintf "\033[3m")SWALLOWEE$($myprintf "\033[0m"). Inverse of the above signature. Visible
+	    windows only.
+
+	  $($myprintf "\033[1m")dwmswallow -h$($myprintf "\033[0m")
+	    Show this usage information.
+	EOF
+	)"
+
+	if [ -n "$1" ]; then
+		echo "$msg" >&2
+		exit "$1"
+	else
+		echo "$msg"
+	fi
+}
+
+# Determine number of leading positional arguments
+arg1="$1" # save for later
+arg2="$2" # save for later
+num_pargs=0
+while :; do
+	case "$1" in
+	-*|"") break ;;
+	*) num_pargs=$((num_pargs + 1)); shift ;;
+	esac
+done
+
+case "$num_pargs" in
+1)
+	! is_winid "$arg1" && usage 1
+
+	widswer="$arg1"
+	if [ "$1" = "-d" ] && [ "$#" -eq 1 ]; then
+		if name="$(printf "${PREFIX}swalunreg${SEP}%u" "$widswer" 2>/dev/null)"; then
+			xsetroot -name "$name"
+		else
+			usage 1
+		fi
+	elif [ "$1" = "-s" ] && [ "$#" -eq 1 ]; then
+		widswee="$arg1"
+		if name="$(printf "${PREFIX}swalstop${SEP}%u" "$widswee" 2>/dev/null)"; then
+			xsetroot -name "$name"
+		else
+			usage 1
+		fi
+	else
+		while :; do
+			case "$1" in
+			-c) [ -n "$2" ] && { class="$2"; shift 2; } || usage 1 ;;
+			-i) [ -n "$2" ] && { instance="$2"; shift 2; } || usage 1 ;;
+			-t) [ -n "$2" ] && { title="$2"; shift 2; } || usage 1 ;;
+			"") break ;;
+			*)	usage 1 ;;
+			esac
+		done
+		widswer="$arg1"
+		if name="$(printf "${PREFIX}swalreg${SEP}%u${SEP}%s${SEP}%s${SEP}%s" "$widswer" "$class" "$instance" "$title" 2>/dev/null)"; then
+			xsetroot -name "$name"
+		else
+			usage 1
+		fi
+	fi
+	;;
+2)
+	! is_winid "$arg1" "$arg2" || [ -n "$1" ] && usage 1
+
+	widswer="$arg1"
+	widswee="$arg2"
+	if name="$(printf "${PREFIX}swal${SEP}%u${SEP}%u" "$widswer" "$widswee" 2>/dev/null)"; then
+		xsetroot -name "$name"
+	else
+		usage 1
+	fi
+	;;
+*)
+	if [ "$arg1" = "-h" ] && [ $# -eq 1 ]; then
+		usage
+	else
+		usage 1
+	fi
+esac