move util.c to util.h

This allows single-source compilation and whole-program optimization using something like:

make CFLAGS='-flto -ffunction-sections -fdata-sections -Wl,--gc-sections'

Furthermore, move more compositor-agnostic utility functions/macros to util.h,
similar to the original dwm sources.

Makefile

@@ -5,7 +5,7 @@ include config.mk
 
 # flags for compiling
 DWLCPPFLAGS = -I. -DWLR_USE_UNSTABLE -D_POSIX_C_SOURCE=200809L \
-	-DVERSION=\"$(VERSION)\" $(XWAYLAND)
+	-DVERSION=\"$(VERSION)\" $(XWAYLAND) $(CPPFLAGS)
 DWLDEVCFLAGS = -g -Wpedantic -Wall -Wextra -Wdeclaration-after-statement \
 	-Wno-unused-parameter -Wshadow -Wunused-macros -Werror=strict-prototypes \
 	-Werror=implicit -Werror=return-type -Werror=incompatible-pointer-types \
@@ -17,12 +17,10 @@ DWLCFLAGS = `$(PKG_CONFIG) --cflags $(PKGS)` $(WLR_INCS) $(DWLCPPFLAGS) $(DWLDEV
 LDLIBS    = `$(PKG_CONFIG) --libs $(PKGS)` $(WLR_LIBS) -lm $(LIBS)
 
 all: dwl
-dwl: dwl.o util.o
-	$(CC) dwl.o util.o $(DWLCFLAGS) $(LDFLAGS) $(LDLIBS) -o $@
-dwl.o: dwl.c client.h config.h config.mk cursor-shape-v1-protocol.h \
+dwl: dwl.c client.h config.h util.h config.mk cursor-shape-v1-protocol.h \
 	pointer-constraints-unstable-v1-protocol.h wlr-layer-shell-unstable-v1-protocol.h \
 	wlr-output-power-management-unstable-v1-protocol.h xdg-shell-protocol.h
-util.o: util.c util.h
+	$(CC) dwl.c $(DWLCFLAGS) $(LDFLAGS) $(LDLIBS) -o $@
 
 # 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
@@ -54,7 +52,7 @@ clean:
 dist: clean
 	mkdir -p dwl-$(VERSION)
 	cp -R LICENSE* Makefile CHANGELOG.md README.md client.h config.def.h \
-		config.mk protocols dwl.1 dwl.c util.c util.h dwl.desktop \
+		config.mk protocols dwl.1 dwl.c util.h dwl.desktop \
 		dwl-$(VERSION)
 	tar -caf dwl-$(VERSION).tar.gz dwl-$(VERSION)
 	rm -rf dwl-$(VERSION)
@@ -73,7 +71,3 @@ install: dwl
 uninstall:
 	rm -f $(DESTDIR)$(PREFIX)/bin/dwl $(DESTDIR)$(MANDIR)/man1/dwl.1 \
 		$(DESTDIR)$(DATADIR)/wayland-sessions/dwl.desktop
-
-.SUFFIXES: .c .o
-.c.o:
-	$(CC) $(CPPFLAGS) $(DWLCFLAGS) -o $@ -c $<

README.md

@@ -1,15 +1,16 @@
 # dwl - dwm for Wayland
 
-Join us on our IRC channel: [#dwl on Libera Chat]  
-Or on the community-maintained [Discord server].
+Join us on our [Discord server]  
+Or Matrix: [#dwl-official:matrix.org]  
+Or on our IRC channel: [#dwl on Libera Chat]
 
 dwl is a compact, hackable compositor for [Wayland] based on [wlroots]. It is
-intended to fill the same space in the Wayland world that dwm does in X11,
+intended to fill the same space in the Wayland world that [dwm] does in X11,
 primarily in terms of functionality, and secondarily in terms of
-philosophy. Like dwm, dwl is:
+philosophy. 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`
+- One C source file configurable via `config.h`
 - Tied to as few external dependencies as possible
 
 ## Getting Started:
@@ -23,12 +24,14 @@ with each release on the [release] page
 
 ### Development branch [main]
 Active development progresses on the `main` branch. The `main` branch is built
-against a late (and often changing) git commit of wlroots. While the adventurous
-are welcome to use `main`, it is a rocky road. Using `main` requires that the
-user be willing to chase git commits of wlroots. Testing development pull
-requests may involve merging unmerged pull requests in [wlroots]' git repository
-and/or git commits of wayland.
-  
+against the latest release of [wlroots]. PRs should target this branch unless they
+depend on functionality that is not in the current release of `wlroots`.
+
+### Preview branch [wlroots-next]
+The `wlroots-next` branch is built against the git version of [wlroots], which
+is unstable and changes frequently. PRs requiring functionality from the git
+version of `wlroots` should target this branch.
+
 ### Building dwl
 dwl has the following dependencies:
 - libinput
@@ -55,11 +58,11 @@ To enable XWayland, you should uncomment its flags in `config.mk`.
 ## Configuration
 
 All configuration is done by editing `config.h` and recompiling, in the same
-manner as dwm. There is no way to separately restart the window manager in
+manner as [dwm]. There is no way to separately restart the window manager in
 Wayland without restarting the entire display server, so any changes will take
 effect the next time dwl is executed.
 
-As in the dwm community, we encourage users to share patches they have
+As in the [dwm] community, we encourage users to share patches they have
 created. Check out the [dwl-patches] repository!
 
 ## Running dwl
@@ -118,17 +121,26 @@ script with the line
 
 To get a list of status bars that work with dwl consult our [wiki].
 
+### (Known) Java nonreparenting WM issue
+Certain IDEs don't display correctly unless an environmental variable for Java AWT
+indicates that the WM is nonreparenting.
+
+For some Java AWT-based IDEs, such as Xilinx Vivado and Microchip MPLAB X, the
+following environment variable needs to be set before running the IDE or dwl:
+
+    export _JAVA_AWT_WM_NONREPARENTING=1
+
 ## Replacements for X applications
 
 You can find a [list of useful resources on our wiki].
 
 ## Background
 
-dwl is not meant to provide every feature under the sun. Instead, like dwm, it
+dwl is not meant to provide every feature under the sun. Instead, like [dwm], it
 sticks to features which are necessary, simple, and straightforward to implement
 given the base on which it is built. Implemented default features are:
 
-- Any features provided by dwm/Xlib: simple window borders, tags, keybindings,
+- 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.
@@ -145,10 +157,10 @@ given the base on which it is built. Implemented default features are:
 - Layer shell popups (used by Waybar)
 - Damage tracking provided by scenegraph API
 
-Given the Wayland architecture, dwl has to implement features from dwm **and**
+Given the Wayland architecture, dwl has to implement features from [dwm] **and**
 the xorg-server. Because of this, it is impossible to maintain the original
 project goal of 2000 SLOC and have a reasonably complete compositor with
-features comparable to dwm. However, this does not mean that the code will grow
+features comparable to [dwm]. However, this does not mean that the code will grow
 indiscriminately. We will try to keep the code as small as possible.
 
 Features under consideration (possibly as patches) are:
@@ -172,7 +184,7 @@ developers. This was made possible in many cases by looking at how sway
 accomplished something, then trying to do the same in as suckless a way as
 possible.
 
-Many thanks to suckless.org and the dwm developers and community for the
+Many thanks to suckless.org and the [dwm] developers and community for the
 inspiration, and to the various contributors to the project, including:
 
 - **Devin J. Pohly for creating and nurturing the fledgling project**
@@ -183,6 +195,7 @@ inspiration, and to the various contributors to the project, including:
 
 
 [wlroots]: https://gitlab.freedesktop.org/wlroots
+[dwm]: https://dwm.suckless.org/
 [`systemd --user`]: https://wiki.archlinux.org/title/Systemd/User
 [#dwl on Libera Chat]: https://web.libera.chat/?channels=#dwl
 [0.7-rc1]: https://codeberg.org/dwl/dwl/releases/tag/v0.7-rc1
@@ -192,6 +205,7 @@ inspiration, and to the various contributors to the project, including:
 [dwl-patches]: https://codeberg.org/dwl/dwl-patches
 [list of useful resources on our wiki]: https://codeberg.org/dwl/dwl/wiki/Home#migrating-from-x
 [main]: https://codeberg.org/dwl/dwl/src/branch/main
+[wlroots-next]: https://codeberg.org/dwl/dwl/src/branch/wlroots-next
 [release]: https://codeberg.org/dwl/dwl/releases
 [runit]: http://smarden.org/runit/faq.html#userservices
 [s6]: https://skarnet.org/software/s6/
@@ -199,3 +213,4 @@ inspiration, and to the various contributors to the project, including:
 [wiki]: https://codeberg.org/dwl/dwl/wiki/Home#compatible-status-bars
 [Discord server]: https://discord.gg/jJxZnrGPWN
 [Wayland]: https://wayland.freedesktop.org/
+[#dwl-official:matrix.org]: https://matrix.to/#/#dwl-official:matrix.org

config.def.h

@@ -20,12 +20,11 @@ static const float fullscreen_bg[]         = {0.0f, 0.0f, 0.0f, 1.0f}; /* You ca
 /* logging */
 static int log_level = WLR_ERROR;
 
-/* NOTE: ALWAYS keep a rule declared even if you don't use rules (e.g leave at least one example) */
 static const Rule rules[] = {
 	/* app_id             title       tags mask     isfloating   monitor */
-	/* examples: */
 	{ "Gimp_EXAMPLE",     NULL,       0,            1,           -1 }, /* Start on currently visible tags floating, not tiled */
 	{ "firefox_EXAMPLE",  NULL,       1 << 8,       0,           -1 }, /* Start on ONLY tag "9" */
+    /* default/example rule: can be changed but cannot be eliminated; at least one rule must exist */
 };
 
 /* layout(s) */
@@ -38,17 +37,14 @@ static const Layout layouts[] = {
 
 /* monitors */
 /* (x=-1, y=-1) is reserved as an "autoconfigure" monitor position indicator
- * WARNING: negative values other than (-1, -1) cause problems with Xwayland clients
- * https://gitlab.freedesktop.org/xorg/xserver/-/issues/899
-*/
-/* NOTE: ALWAYS add a fallback rule, even if you are completely sure it won't be used */
+ * WARNING: negative values other than (-1, -1) cause problems with Xwayland clients due to
+ * https://gitlab.freedesktop.org/xorg/xserver/-/issues/899 */
 static const MonitorRule monrules[] = {
-	/* name       mfact  nmaster scale layout       rotate/reflect                x    y */
-	/* example of a HiDPI laptop monitor:
-	{ "eDP-1",    0.5f,  1,      2,    &layouts[0], WL_OUTPUT_TRANSFORM_NORMAL,   -1,  -1 },
-	*/
-	/* defaults */
+   /* name        mfact  nmaster scale layout       rotate/reflect                x    y
+    * example of a HiDPI laptop monitor:
+    { "eDP-1",    0.5f,  1,      2,    &layouts[0], WL_OUTPUT_TRANSFORM_NORMAL,   -1,  -1 }, */
 	{ NULL,       0.55f, 1,      1,    &layouts[0], WL_OUTPUT_TRANSFORM_NORMAL,   -1,  -1 },
+	/* default monitor rule: can be changed but cannot be eliminated; at least one monitor rule must exist */
 };
 
 /* keyboard */
@@ -123,41 +119,41 @@ static const char *termcmd[] = { "foot", NULL };
 static const char *menucmd[] = { "wmenu-run", NULL };
 
 static const Key keys[] = {
-	/* Note that Shift changes certain key codes: c -> C, 2 -> at, etc. */
-	/* modifier                  key                 function        argument */
-	{ MODKEY,                    XKB_KEY_p,          spawn,          {.v = menucmd} },
-	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_Return,     spawn,          {.v = termcmd} },
-	{ MODKEY,                    XKB_KEY_j,          focusstack,     {.i = +1} },
-	{ MODKEY,                    XKB_KEY_k,          focusstack,     {.i = -1} },
-	{ MODKEY,                    XKB_KEY_i,          incnmaster,     {.i = +1} },
-	{ MODKEY,                    XKB_KEY_d,          incnmaster,     {.i = -1} },
-	{ MODKEY,                    XKB_KEY_h,          setmfact,       {.f = -0.05f} },
-	{ MODKEY,                    XKB_KEY_l,          setmfact,       {.f = +0.05f} },
-	{ MODKEY,                    XKB_KEY_Return,     zoom,           {0} },
-	{ MODKEY,                    XKB_KEY_Tab,        view,           {0} },
-	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_C,          killclient,     {0} },
-	{ MODKEY,                    XKB_KEY_t,          setlayout,      {.v = &layouts[0]} },
-	{ MODKEY,                    XKB_KEY_f,          setlayout,      {.v = &layouts[1]} },
-	{ 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_0,          view,           {.ui = ~0} },
-	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_parenright, tag,            {.ui = ~0} },
-	{ MODKEY,                    XKB_KEY_comma,      focusmon,       {.i = WLR_DIRECTION_LEFT} },
-	{ MODKEY,                    XKB_KEY_period,     focusmon,       {.i = WLR_DIRECTION_RIGHT} },
-	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_less,       tagmon,         {.i = WLR_DIRECTION_LEFT} },
-	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_greater,    tagmon,         {.i = WLR_DIRECTION_RIGHT} },
-	TAGKEYS(          XKB_KEY_1, XKB_KEY_exclam,                     0),
-	TAGKEYS(          XKB_KEY_2, XKB_KEY_at,                         1),
-	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_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),
-	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_Q,          quit,           {0} },
+	/* Note that Shift changes certain key codes: 2 -> at, etc. */
+	/* modifier                  key                  function          argument */
+	{ MODKEY,                    XKB_KEY_p,           spawn,            {.v = menucmd} },
+	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_Return,      spawn,            {.v = termcmd} },
+	{ MODKEY,                    XKB_KEY_j,           focusstack,       {.i = +1} },
+	{ MODKEY,                    XKB_KEY_k,           focusstack,       {.i = -1} },
+	{ MODKEY,                    XKB_KEY_i,           incnmaster,       {.i = +1} },
+	{ MODKEY,                    XKB_KEY_d,           incnmaster,       {.i = -1} },
+	{ MODKEY,                    XKB_KEY_h,           setmfact,         {.f = -0.05f} },
+	{ MODKEY,                    XKB_KEY_l,           setmfact,         {.f = +0.05f} },
+	{ MODKEY,                    XKB_KEY_Return,      zoom,             {0} },
+	{ MODKEY,                    XKB_KEY_Tab,         view,             {0} },
+	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_c,           killclient,       {0} },
+	{ MODKEY,                    XKB_KEY_t,           setlayout,        {.v = &layouts[0]} },
+	{ MODKEY,                    XKB_KEY_f,           setlayout,        {.v = &layouts[1]} },
+	{ 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_0,           view,             {.ui = ~0} },
+	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_parenright,  tag,              {.ui = ~0} },
+	{ MODKEY,                    XKB_KEY_comma,       focusmon,         {.i = WLR_DIRECTION_LEFT} },
+	{ MODKEY,                    XKB_KEY_period,      focusmon,         {.i = WLR_DIRECTION_RIGHT} },
+	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_less,        tagmon,           {.i = WLR_DIRECTION_LEFT} },
+	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_greater,     tagmon,           {.i = WLR_DIRECTION_RIGHT} },
+	TAGKEYS(          XKB_KEY_1, XKB_KEY_exclam,                        0),
+	TAGKEYS(          XKB_KEY_2, XKB_KEY_at,                            1),
+	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_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),
+	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_q,           quit,             {0} },
 
 	/* Ctrl-Alt-Backspace and Ctrl-Alt-Fx used to be handled by X server */
 	{ WLR_MODIFIER_CTRL|WLR_MODIFIER_ALT,XKB_KEY_Terminate_Server, quit, {0} },

dwl.c

@@ -24,6 +24,7 @@
 #include <wlr/types/wlr_data_device.h>
 #include <wlr/types/wlr_drm.h>
 #include <wlr/types/wlr_export_dmabuf_v1.h>
+#include <wlr/types/wlr_ext_data_control_v1.h>
 #include <wlr/types/wlr_fractional_scale_v1.h>
 #include <wlr/types/wlr_gamma_control_v1.h>
 #include <wlr/types/wlr_idle_inhibit_v1.h>
@@ -71,12 +72,8 @@
 #include "util.h"
 
 /* macros */
-#define MAX(A, B)               ((A) > (B) ? (A) : (B))
-#define MIN(A, B)               ((A) < (B) ? (A) : (B))
 #define CLEANMASK(mask)         (mask & ~WLR_MODIFIER_CAPS)
 #define VISIBLEON(C, M)         ((M) && (C)->mon == (M) && ((C)->tags & (M)->tagset[(M)->seltags]))
-#define LENGTH(X)               (sizeof X / sizeof X[0])
-#define END(A)                  ((A) + LENGTH(A))
 #define TAGMASK                 ((1u << TAGCOUNT) - 1)
 #define LISTEN(E, L, H)         wl_signal_add((E), ((L)->notify = (H), (L)))
 #define LISTEN_STATIC(E, H)     do { struct wl_listener *_l = ecalloc(1, sizeof(*_l)); _l->notify = (H); wl_signal_add((E), _l); } while (0)
@@ -585,7 +582,7 @@ arrangelayers(Monitor *m)
 		arrange(m);
 	}
 
-	/* Arrange non-exlusive surfaces from top->bottom */
+	/* Arrange non-exclusive surfaces from top->bottom */
 	for (i = 3; i >= 0; i--)
 		arrangelayer(m, &m->layers[i], &usable_area, 0);
 
@@ -1616,7 +1613,8 @@ keybinding(uint32_t mods, xkb_keysym_t sym)
 	const Key *k;
 	for (k = keys; k < END(keys); k++) {
 		if (CLEANMASK(mods) == CLEANMASK(k->mod)
-				&& sym == k->keysym && k->func) {
+				&& xkb_keysym_to_lower(sym) == xkb_keysym_to_lower(k->keysym)
+				&& k->func) {
 			k->func(&k->arg);
 			return 1;
 		}
@@ -2132,7 +2130,7 @@ powermgrsetmode(struct wl_listener *listener, void *data)
 	if (!m)
 		return;
 
-	m->gamma_lut_changed = 1; /* Reapply gamma LUT when re-enabling the ouput */
+	m->gamma_lut_changed = 1; /* Reapply gamma LUT when re-enabling the output */
 	wlr_output_state_set_enabled(&state, event->mode);
 	wlr_output_commit_state(m->wlr_output, &state);
 
@@ -2454,7 +2452,7 @@ setup(void)
 	wlr_log_init(log_level, NULL);
 
 	/* The Wayland display is managed by libwayland. It handles accepting
-	 * clients from the Unix socket, manging Wayland globals, and so on. */
+	 * clients from the Unix socket, managing Wayland globals, and so on. */
 	dpy = wl_display_create();
 	event_loop = wl_display_get_event_loop(dpy);
 
@@ -2517,6 +2515,7 @@ setup(void)
 	wlr_export_dmabuf_manager_v1_create(dpy);
 	wlr_screencopy_manager_v1_create(dpy);
 	wlr_data_control_manager_v1_create(dpy);
+	wlr_ext_data_control_manager_v1_create(dpy, 1);
 	wlr_primary_selection_v1_device_manager_create(dpy);
 	wlr_viewporter_create(dpy);
 	wlr_single_pixel_buffer_manager_v1_create(dpy);

util.c

@@ -1,51 +0,0 @@
-/* See LICENSE.dwm file for copyright and license details. */
-#include <stdarg.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <fcntl.h>
-
-#include "util.h"
-
-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);
-}
-
-void *
-ecalloc(size_t nmemb, size_t size)
-{
-	void *p;
-
-	if (!(p = calloc(nmemb, size)))
-		die("calloc:");
-	return p;
-}
-
-int
-fd_set_nonblock(int fd) {
-	int flags = fcntl(fd, F_GETFL);
-	if (flags < 0) {
-		perror("fcntl(F_GETFL):");
-		return -1;
-	}
-	if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) < 0) {
-		perror("fcntl(F_SETFL):");
-		return -1;
-	}
-
-	return 0;
-}

util.h

@@ -1,5 +1,58 @@
 /* See LICENSE.dwm file for copyright and license details. */
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
 
-void die(const char *fmt, ...);
-void *ecalloc(size_t nmemb, size_t size);
-int fd_set_nonblock(int fd);
+#define MAX(A, B)               ((A) > (B) ? (A) : (B))
+#define MIN(A, B)               ((A) < (B) ? (A) : (B))
+#define LENGTH(X)               (sizeof X / sizeof X[0])
+#define END(A)                  ((A) + LENGTH(A))
+
+static void die(const char *fmt, ...);
+static void *ecalloc(size_t nmemb, size_t size);
+static int fd_set_nonblock(int fd);
+
+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);
+}
+
+void *
+ecalloc(size_t nmemb, size_t size)
+{
+	void *p;
+
+	if (!(p = calloc(nmemb, size)))
+		die("calloc:");
+	return p;
+}
+
+int
+fd_set_nonblock(int fd) {
+	int flags = fcntl(fd, F_GETFL);
+	if (flags < 0) {
+		perror("fcntl(F_GETFL):");
+		return -1;
+	}
+	if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) < 0) {
+		perror("fcntl(F_SETFL):");
+		return -1;
+	}
+
+	return 0;
+}