dwl: don't show input popup if client is not enabled

We link clients and their input popups which lets us disable the popups'
scene nodes in case the associated client's scene is not enabled on a tag.

.github/ISSUE_TEMPLATE/bug_report.md

@@ -7,4 +7,16 @@ assignees: ''
 
 ---
 
+## Info
+dwl's commit:
+wlroots version:
+## Description
+<!--
+Only report bugs that can be reproduced on the main line
+Report patch issues to their respective authors
+If the patch author doesn't respond within a reasonable time, email me:
 
+Leonardo Hernández Hernández <leohdz172@protonmail.com>
+
+but note that I'm NOT making any promises
+-->

LICENSE

@@ -2,7 +2,7 @@ dwl - dwm for Wayland
 
 Copyright © 2020 dwl team
 
-See also the files LICENSE.tinywl and LICENSE.dwm.
+See also the files LICENSE.tinywl, LICENSE.dwm and LICENSE.sway.
 
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by

LICENSE.sway

@@ -0,0 +1,19 @@
+Copyright (c) 2016-2017 Drew DeVault
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

Makefile

@@ -1,6 +1,6 @@
 include config.mk
 
-CFLAGS += -I. -DWLR_USE_UNSTABLE -std=c99
+CFLAGS += -I. -DWLR_USE_UNSTABLE -std=c99 -pedantic -DVERSION=\"$(VERSION)\"
 
 WAYLAND_PROTOCOLS=$(shell pkg-config --variable=pkgdatadir wayland-protocols)
 WAYLAND_SCANNER=$(shell pkg-config --variable=wayland_scanner wayland-scanner)
@@ -14,13 +14,23 @@ all: dwl
 clean:
 	rm -f dwl *.o *-protocol.h *-protocol.c
 
+dist: clean
+	mkdir -p dwl-$(VERSION)
+	cp -R LICENSE* Makefile README.md generate-version.sh client.h\
+		config.def.h config.mk protocols dwl.1 dwl.c util.c util.h\
+		dwl-$(VERSION)
+	echo "echo $(VERSION)" > dwl-$(VERSION)/generate-version.sh
+	tar -caf dwl-$(VERSION).tar.gz dwl-$(VERSION)
+	rm -rf dwl-$(VERSION)
+
 install: dwl
-	install -D dwl $(PREFIX)/bin/dwl
+	install -Dm755 dwl $(DESTDIR)$(PREFIX)/bin/dwl
+	install -Dm644 dwl.1 $(DESTDIR)$(MANDIR)/man1/dwl.1
 
 uninstall:
-	rm -f $(PREFIX)/bin/dwl
+	rm -f $(DESTDIR)$(PREFIX)/bin/dwl $(DESTDIR)$(MANDIR)/man1/dwl.1
 
-.PHONY: all clean install uninstall
+.PHONY: all clean dist install uninstall
 
 # wayland-scanner is a tool which generates C headers and rigging for Wayland
 # protocols, which are specified in XML. wlroots requires you to rig these up
@@ -58,6 +68,6 @@ idle-protocol.o: idle-protocol.h
 config.h: | config.def.h
 	cp config.def.h $@
 
-dwl.o: config.mk config.h client.h xdg-shell-protocol.h wlr-layer-shell-unstable-v1-protocol.h idle-protocol.h
+dwl.o: config.mk config.h client.h xdg-shell-protocol.h wlr-layer-shell-unstable-v1-protocol.h idle-protocol.h util.h
 
-dwl: xdg-shell-protocol.o wlr-layer-shell-unstable-v1-protocol.o idle-protocol.o
+dwl: xdg-shell-protocol.o wlr-layer-shell-unstable-v1-protocol.o idle-protocol.o util.o

README.md

@@ -2,7 +2,7 @@
 
 Join us on our [Discord server](https://discord.gg/jJxZnrGPWN)!
 
-dwl is a compact, hackable compositor for Wayland based on [wlroots](https://github.com/swaywm/wlroots). It is intended to fill the same space in the Wayland world that dwm does in X11, primarily in terms of philosophy, and secondarily in terms of functionality. Like dwm, dwl is:
+dwl is a compact, hackable compositor for Wayland based on [wlroots](https://gitlab.freedesktop.org/wlroots/wlroots/). It is intended to fill the same space in the Wayland world that dwm does in X11, primarily in terms of philosophy, and secondarily in terms of functionality. Like dwm, dwl is:
 
 - Easy to understand, hack on, and extend with patches
 - One C source file (or a very small number) configurable via `config.h`
@@ -14,20 +14,19 @@ dwl is not meant to provide every feature under the sun. Instead, like dwm, it s
 - Any features provided by dwm/Xlib: simple window borders, tags, keybindings, client rules, mouse move/resize. Providing a built-in status bar is an exception to this goal, to avoid dependencies on font rendering and/or drawing libraries when an external bar could work well.
 - Configurable multi-monitor layout support, including position and rotation
 - Configurable HiDPI/multi-DPI support
+- Idle-inhibit protocol which lets applications such as mpv disable idle monitoring
 - Provide information to external status bars via stdout/stdin
 - Urgency hints via xdg-activate protocol
+- Support screen lockers via input-inhibitor protocol
 - Various Wayland protocols
 - XWayland support as provided by wlroots (can be enabled in `config.mk`)
 - Zero flickering - Wayland users naturally expect that "every frame is perfect"
+- Layer shell popups (used by Waybar)
+- Damage tracking provided by scenegraph API
 
 Features under consideration (possibly as patches) are:
 
 - Protocols made trivial by wlroots
-- Implement the input-inhibitor protocol to support screen lockers
-- Implement the idle-inhibit protocol which lets applications such as mpv disable idle monitoring
-- Layer shell popups (used by Waybar)
-- Basic yes/no damage tracking to avoid needless redraws
-- More in-depth damage region tracking ([which may improve power usage](https://mozillagfx.wordpress.com/2019/10/22/dramatically-reduced-power-usage-in-firefox-70-on-macos-with-core-animation/))
 - Implement the text-input and input-method protocols to support IME once ibus implements input-method v2 (see https://github.com/ibus/ibus/pull/2256 and https://github.com/djpohly/dwl/pull/12)
 
 Feature *non-goals* for the main codebase include:
@@ -78,7 +77,7 @@ You can find a [list of Wayland applications on the sway wiki](https://github.co
 
 ## IRC channel
 
-dwl's IRC channel is #dwl on irc.freenode.net.
+dwl's IRC channel is #dwl on irc.libera.chat.
 
 ## Acknowledgements
 

client.h

@@ -30,16 +30,19 @@ client_surface(Client *c)
 static inline void
 client_activate_surface(struct wlr_surface *s, int activated)
 {
+	struct wlr_xdg_surface *surface;
 #ifdef XWAYLAND
-	if (wlr_surface_is_xwayland_surface(s)) {
-		wlr_xwayland_surface_activate(
-				wlr_xwayland_surface_from_wlr_surface(s), activated);
+	struct wlr_xwayland_surface *xsurface;
+	if (wlr_surface_is_xwayland_surface(s)
+			&& (xsurface = wlr_xwayland_surface_from_wlr_surface(s))) {
+		wlr_xwayland_surface_activate(xsurface, activated);
 		return;
 	}
 #endif
-	if (wlr_surface_is_xdg_surface(s))
-		wlr_xdg_toplevel_set_activated(
-				wlr_xdg_surface_from_wlr_surface(s), activated);
+	if (wlr_surface_is_xdg_surface(s)
+			&& (surface = wlr_xdg_surface_from_wlr_surface(s))
+			&& surface->role == WLR_XDG_SURFACE_ROLE_TOPLEVEL)
+		wlr_xdg_toplevel_set_activated(surface, activated);
 }
 
 static inline void
@@ -90,17 +93,50 @@ client_get_title(Client *c)
 
 static inline int
 client_is_float_type(Client *c)
+{
+	struct wlr_xdg_toplevel *toplevel;
+	struct wlr_xdg_toplevel_state state;
+
+#ifdef XWAYLAND
+	if (client_is_x11(c)) {
+		struct wlr_xwayland_surface *surface = c->surface.xwayland;
+		struct wlr_xwayland_surface_size_hints *size_hints;
+		if (surface->modal)
+			return 1;
+
+		for (size_t i = 0; i < surface->window_type_len; i++)
+			if (surface->window_type[i] == netatom[NetWMWindowTypeDialog] ||
+					surface->window_type[i] == netatom[NetWMWindowTypeSplash] ||
+					surface->window_type[i] == netatom[NetWMWindowTypeToolbar] ||
+					surface->window_type[i] == netatom[NetWMWindowTypeUtility])
+				return 1;
+
+		size_hints = surface->size_hints;
+		if (size_hints && size_hints->min_width > 0 && size_hints->min_height > 0
+				&& (size_hints->max_width == size_hints->min_width ||
+				size_hints->max_height == size_hints->min_height))
+			return 1;
+
+		return 0;
+	}
+#endif
+
+	toplevel = c->surface.xdg->toplevel;
+	state = toplevel->current;
+	return (state.min_width != 0 && state.min_height != 0
+		&& (state.min_width == state.max_width
+		|| state.min_height == state.max_height))
+		|| toplevel->parent;
+}
+
+static inline int
+client_wants_fullscreen(Client *c)
 {
 #ifdef XWAYLAND
 	if (client_is_x11(c))
-		for (size_t i = 0; i < c->surface.xwayland->window_type_len; i++)
-			if (c->surface.xwayland->window_type[i] == netatom[NetWMWindowTypeDialog] ||
-					c->surface.xwayland->window_type[i] == netatom[NetWMWindowTypeSplash] ||
-					c->surface.xwayland->window_type[i] == netatom[NetWMWindowTypeToolbar] ||
-					c->surface.xwayland->window_type[i] == netatom[NetWMWindowTypeUtility])
-				return 1;
+		return c->surface.xwayland->fullscreen;
 #endif
-	return 0;
+	return c->surface.xdg->toplevel->requested.fullscreen;
 }
 
 static inline int
@@ -156,8 +192,7 @@ client_set_tiled(Client *c, uint32_t edges)
 	if (client_is_x11(c))
 		return;
 #endif
-	wlr_xdg_toplevel_set_tiled(c->surface.xdg, WLR_EDGE_TOP |
-			WLR_EDGE_BOTTOM | WLR_EDGE_LEFT | WLR_EDGE_RIGHT);
+	wlr_xdg_toplevel_set_tiled(c->surface.xdg, edges);
 }
 
 static inline struct wlr_surface *
@@ -170,3 +205,56 @@ client_surface_at(Client *c, double cx, double cy, double *sx, double *sy)
 #endif
 	return wlr_xdg_surface_surface_at(c->surface.xdg, cx, cy, sx, sy);
 }
+
+static inline void
+client_min_size(Client *c, int *width, int *height)
+{
+	struct wlr_xdg_toplevel *toplevel;
+	struct wlr_xdg_toplevel_state *state;
+#ifdef XWAYLAND
+	if (client_is_x11(c)) {
+		struct wlr_xwayland_surface_size_hints *size_hints;
+		size_hints = c->surface.xwayland->size_hints;
+		if (size_hints) {
+			*width = size_hints->min_width;
+			*height = size_hints->min_height;
+		} else {
+			*width = 0;
+			*height = 0;
+		}
+		return;
+	}
+#endif
+	toplevel = c->surface.xdg->toplevel;
+	state = &toplevel->current;
+	*width = state->min_width;
+	*height = state->min_height;
+}
+
+static inline Client *
+client_from_wlr_surface(struct wlr_surface *surface)
+{
+	struct wlr_scene_node *n = surface->data;
+	return n ? n->data : NULL;
+}
+
+static inline Client *
+client_from_popup(struct wlr_xdg_popup *popup)
+{
+	struct wlr_xdg_surface *surface = popup->base;
+
+	while (1) {
+		switch (surface->role) {
+		case WLR_XDG_SURFACE_ROLE_POPUP:
+			if (!wlr_surface_is_xdg_surface(surface->popup->parent))
+				return NULL;
+
+			surface = wlr_xdg_surface_from_wlr_surface(surface->popup->parent);
+			break;
+		case WLR_XDG_SURFACE_ROLE_TOPLEVEL:
+				return surface->data;
+		case WLR_XDG_SURFACE_ROLE_NONE:
+			return NULL;
+		}
+	}
+}

config.def.h

@@ -1,6 +1,7 @@
 /* appearance */
 static const int sloppyfocus        = 1;  /* focus follows mouse */
 static const unsigned int borderpx  = 1;  /* border pixel of windows */
+static const int lockfullscreen     = 1;  /* 1 will force focus on the fullscreen window */
 static const float rootcolor[]      = {0.3, 0.3, 0.3, 1.0};
 static const float bordercolor[]    = {0.5, 0.5, 0.5, 1.0};
 static const float focuscolor[]     = {1.0, 0.0, 0.0, 1.0};
@@ -12,8 +13,8 @@ static const Rule rules[] = {
 	/* app_id     title       tags mask     isfloating   monitor */
 	/* examples:
 	{ "Gimp",     NULL,       0,            1,           -1 },
-	{ "firefox",  NULL,       1 << 8,       0,           -1 },
 	*/
+	{ "firefox",  NULL,       1 << 8,       0,           -1 },
 };
 
 /* layout(s) */
@@ -24,16 +25,14 @@ static const Layout layouts[] = {
 	{ "[M]",      monocle },
 };
 
-/* monitors
- * The order in which monitors are defined determines their position.
- * Non-configured monitors are always added to the left. */
+/* monitors */
 static const MonitorRule monrules[] = {
-	/* name       mfact nmaster scale layout       rotate/reflect x y */
+	/* name       mfact nmaster scale layout       rotate/reflect */
 	/* example of a HiDPI laptop monitor:
-	{ "eDP-1",    0.5,  1,      2,    &layouts[0], WL_OUTPUT_TRANSFORM_NORMAL, 0, 0 },
+	{ "eDP-1",    0.5,  1,      2,    &layouts[0], WL_OUTPUT_TRANSFORM_NORMAL },
 	*/
 	/* defaults */
-	{ NULL,       0.55, 1,      1,    &layouts[0], WL_OUTPUT_TRANSFORM_NORMAL, 0, 0 },
+	{ NULL,       0.55, 1,      1,    &layouts[0], WL_OUTPUT_TRANSFORM_NORMAL },
 };
 
 /* keyboard */
@@ -42,6 +41,7 @@ static const struct xkb_rule_names xkb_rules = {
 	/* example:
 	.options = "ctrl:nocaps",
 	*/
+	.options = "",
 };
 
 static const int repeat_rate = 25;
@@ -49,8 +49,33 @@ static const int repeat_delay = 600;
 
 /* Trackpad */
 static const int tap_to_click = 1;
+static const int tap_and_drag = 1;
+static const int drag_lock = 1;
 static const int natural_scrolling = 0;
+static const int disable_while_typing = 1;
+static const int left_handed = 0;
+static const int middle_button_emulation = 0;
+/* You can choose between:
+LIBINPUT_CONFIG_SCROLL_NO_SCROLL
+LIBINPUT_CONFIG_SCROLL_2FG
+LIBINPUT_CONFIG_SCROLL_EDGE
+LIBINPUT_CONFIG_SCROLL_ON_BUTTON_DOWN
+*/
+static const enum libinput_config_scroll_method scroll_method = LIBINPUT_CONFIG_SCROLL_2FG;
+/* You can choose between:
+LIBINPUT_CONFIG_SEND_EVENTS_ENABLED
+LIBINPUT_CONFIG_SEND_EVENTS_DISABLED
+LIBINPUT_CONFIG_SEND_EVENTS_DISABLED_ON_EXTERNAL_MOUSE
+*/
+static const uint32_t send_events_mode = LIBINPUT_CONFIG_SEND_EVENTS_ENABLED;
+/* You can choose between:
+LIBINPUT_CONFIG_ACCEL_PROFILE_FLAT
+LIBINPUT_CONFIG_ACCEL_PROFILE_ADAPTIVE
+*/
+static const enum libinput_config_accel_profile accel_profile = LIBINPUT_CONFIG_ACCEL_PROFILE_ADAPTIVE;
+static const double accel_speed = 0.0;
 
+/* If you want to use the windows key change this to WLR_MODIFIER_LOGO */
 #define MODKEY WLR_MODIFIER_ALT
 #define TAGKEYS(KEY,SKEY,TAG) \
 	{ MODKEY,                    KEY,            view,            {.ui = 1 << TAG} }, \
@@ -84,7 +109,7 @@ static const Key keys[] = {
 	{ MODKEY,                    XKB_KEY_m,          setlayout,      {.v = &layouts[2]} },
 	{ MODKEY,                    XKB_KEY_space,      setlayout,      {0} },
 	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_space,      togglefloating, {0} },
-	{ MODKEY, 					 XKB_KEY_e,    		togglefullscreen, {0} },
+	{ MODKEY,                    XKB_KEY_e,         togglefullscreen, {0} },
 	{ MODKEY,                    XKB_KEY_0,          view,           {.ui = ~0} },
 	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_parenright, tag,            {.ui = ~0} },
 	{ MODKEY,                    XKB_KEY_comma,      focusmon,       {.i = WLR_DIRECTION_LEFT} },
@@ -96,7 +121,7 @@ static const Key keys[] = {
 	TAGKEYS(          XKB_KEY_3, XKB_KEY_numbersign,                 2),
 	TAGKEYS(          XKB_KEY_4, XKB_KEY_dollar,                     3),
 	TAGKEYS(          XKB_KEY_5, XKB_KEY_percent,                    4),
-	TAGKEYS(          XKB_KEY_6, XKB_KEY_caret,                      5),
+	TAGKEYS(          XKB_KEY_6, XKB_KEY_asciicircum,                5),
 	TAGKEYS(          XKB_KEY_7, XKB_KEY_ampersand,                  6),
 	TAGKEYS(          XKB_KEY_8, XKB_KEY_asterisk,                   7),
 	TAGKEYS(          XKB_KEY_9, XKB_KEY_parenleft,                  8),

config.mk

@@ -1,8 +1,12 @@
+_VERSION = 0.3.1
+VERSION = $(shell ./generate-version.sh $(_VERSION))
+
 # paths
 PREFIX = /usr/local
+MANDIR = $(PREFIX)/share/man
 
 # Default compile flags (overridable by environment)
-CFLAGS ?= -g -Wall -Wextra -Werror -Wno-unused-parameter -Wno-sign-compare -Wno-unused-function -Wno-unused-variable -Wdeclaration-after-statement
+CFLAGS ?= -g -Wall -Wextra -Werror -Wno-unused-parameter -Wno-sign-compare -Wno-unused-function -Wno-unused-variable -Wno-unused-result -Wdeclaration-after-statement
 
 # Uncomment to build XWayland support
 #CFLAGS += -DXWAYLAND

dwl.1

@@ -0,0 +1,151 @@
+.Dd January 8, 2021
+.Dt DWL 1
+.Os
+.Sh NAME
+.Nm dwl
+.Nd dwm for Wayland
+.Sh SYNOPSIS
+.Nm
+.Op Fl v
+.Op Fl s Ar startup command
+.Sh DESCRIPTION
+.Nm
+is a Wayland compositor based on wlroots.
+It is intended to fill the same space in the Wayland world that
+.Nm dwm
+does for X11.
+.Pp
+When given the
+.Fl v
+option,
+.Nm
+writes its name and version to standard error and exits unsuccessfully.
+.Pp
+When given the
+.Fl s
+option,
+.Nm
+starts a shell process running
+.Ar command
+when starting.
+When stopping, it sends
+.Dv SIGTERM
+to the child process and waits for it to exit.
+.Pp
+Users are encouraged to customize
+.Nm
+by editing the sources, in particular
+.Pa config.h .
+The default key bindings are as follows:
+.Bl -tag -width 20n -offset indent -compact
+.It Mod-[1-9]
+Show only all windows with a tag.
+.It Mod-Ctrl-[1-9]
+Show all windows with a tag.
+.It Mod-Shift-[1-9]
+Move window to a single tag.
+.It Mod-Ctrl-Shift-[1-9]
+Toggle tag for window.
+.It Mod-p
+Spawn
+.Nm bemenu-run .
+.It Mod-Shift-Return
+Spawn
+.Nm alacritty .
+.It Mod-[jk]
+Move focus down/up the stack.
+.It Mod-[id]
+Increase/decrease number of windows in master area.
+.It Mod-[hl]
+Decrease/increase master area.
+.It Mod-Return
+Move window on top of stack or switch top of stack with second window.
+.It Mod-Tab
+Show only all windows with previous tag.
+.It Mod-Shift-c
+Close window.
+.It Mod-t
+Switch to tabbed layout.
+.It Mod-f
+Switch to floating layout.
+.It Mod-m
+Switch to monocle layout.
+.It Mod-Space
+Switch to previous layout.
+.It Mod-Shift-Space
+Toggle floating state of window.
+.It Mod-e
+Toggle fullscreen state of window.
+.It Mod-0
+Show all windows.
+.It Mod-Shift-0
+Set all tags for window.
+.It Mod-,
+Move focus to previous monitor.
+.It Mod-.
+Move focus to next monitor.
+.It Mod-Shift-,
+Move window to previous monitor.
+.It Mod-Shift-.
+Move window to next monitor.
+.It Mod-Shift-q
+Quit
+.Nm .
+.El
+These might differ depending on your keyboard layout.
+.Sh ENVIRONMENT
+These environment variables are used by
+.Nm :
+.Bl -tag -width XDG_RUNTIME_DIR
+.It Ev XDG_RUNTIME_DIR
+A directory where temporary user files, such as the Wayland socket,
+are stored.
+.It Ev XDG_CONFIG_DIR
+A directory containung configuration of various programs and
+libraries, including libxkbcommon.
+.It Ev DISPLAY , WAYLAND_DISPLAY , WAYLAND_SOCKET
+Tell how to connect to an underlying X11 or Wayland server.
+.It Ev WLR_*
+Various variables specific to wlroots.
+.It Ev XKB_* , XLOCALEDIR , XCOMPOSEFILE
+Various variables specific to libxkbcommon.
+.It Ev XCURSOR_PATH
+List of directories to search for XCursor themes in.
+.It Ev HOME
+A directory where there are always dear files there for you.
+Waiting for you to clean them up.
+.El
+.Pp
+These are set by
+.Nm :
+.Bl -tag -width WAYLAND_DISPLAY
+.It Ev WAYLAND_DISPLAY
+Tell how to connect to
+.Nm .
+.It Ev DISPLAY
+If using
+.Nm Xwayland ,
+tell how to connect to the
+.Nm Xwayland
+server.
+.El
+.Sh EXAMPLES
+Start
+.Nm
+with s6 in the background:
+.Dl dwl -s 's6-svscan <&-'
+.Sh SEE ALSO
+.Xr alacritty 1 ,
+.Xr bemenu 1 ,
+.Xr dwm 1 ,
+.Xr xkeyboard-config 7
+.Sh CAVEATS
+The child process's standard input is connected with a pipe to
+.Nm .
+If the child process neither reads from the pipe nor closes its
+standard input,
+.Nm
+will freeze after a while due to it blocking when writing to the full
+pipe buffer.
+.Sh BUGS
+All of them.

generate-version.sh

@@ -0,0 +1,13 @@
+#!/bin/sh
+
+if git tag --contains HEAD | grep -q $1; then
+	echo $1
+else
+	branch="$(git rev-parse --abbrev-ref HEAD)"
+	commit="$(git rev-parse --short HEAD)"
+	if [ "${branch}" != "main" ]; then
+		echo $1-$branch-$commit
+	else
+		echo $1-$commit
+	fi
+fi

util.c

@@ -0,0 +1,35 @@
+/* See LICENSE.dwm file for copyright and license details. */
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "util.h"
+
+void *
+ecalloc(size_t nmemb, size_t size)
+{
+	void *p;
+
+	if (!(p = calloc(nmemb, size)))
+		die("calloc:");
+	return p;
+}
+
+void
+die(const char *fmt, ...) {
+	va_list ap;
+
+	va_start(ap, fmt);
+	vfprintf(stderr, fmt, ap);
+	va_end(ap);
+
+	if (fmt[0] && fmt[strlen(fmt)-1] == ':') {
+		fputc(' ', stderr);
+		perror(NULL);
+	} else {
+		fputc('\n', stderr);
+	}
+
+	exit(1);
+}

util.h

@@ -0,0 +1,4 @@
+/* See LICENSE.dwm file for copyright and license details. */
+
+void die(const char *fmt, ...);
+void *ecalloc(size_t nmemb, size_t size);