init commit

19 files changed, 1268 insertions, 0 deletions

diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..2e4419b
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,24 @@
+MIT/X Consortium License
+
+© 2015-2016 Markus Teich <markus.teich@stusta.mhn.de>
+© 2014 Dimitris Papastamos <sin@2f30.org>
+© 2006-2014 Anselm R Garbe <anselm@garbe.us>
+© 2014-2016 Laslo Hunhold <dev@frign.de>
+
+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.
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..f4ffbb7
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,61 @@
+# slock - simple screen locker
+# See LICENSE file for copyright and license details.
+
+include config.mk
+
+SRC = slock.c ${COMPATSRC}
+OBJ = ${SRC:.c=.o}
+
+all: options slock
+
+options:
+	@echo slock build options:
+	@echo "CFLAGS   = ${CFLAGS}"
+	@echo "LDFLAGS  = ${LDFLAGS}"
+	@echo "CC       = ${CC}"
+
+.c.o:
+	@echo CC $<
+	@${CC} -c ${CFLAGS} $<
+
+${OBJ}: config.h config.mk arg.h util.h
+
+config.h:
+	@echo creating $@ from config.def.h
+	@cp config.def.h $@
+
+slock: ${OBJ}
+	@echo CC -o $@
+	@${CC} -o $@ ${OBJ} ${LDFLAGS}
+
+clean:
+	@echo cleaning
+	@rm -f slock ${OBJ} slock-${VERSION}.tar.gz
+
+dist: clean
+	@echo creating dist tarball
+	@mkdir -p slock-${VERSION}
+	@cp -R LICENSE Makefile README slock.1 config.mk \
+		${SRC} explicit_bzero.c config.def.h arg.h util.h slock-${VERSION}
+	@tar -cf slock-${VERSION}.tar slock-${VERSION}
+	@gzip slock-${VERSION}.tar
+	@rm -rf slock-${VERSION}
+
+install: all
+	@echo installing executable file to ${DESTDIR}${PREFIX}/bin
+	@mkdir -p ${DESTDIR}${PREFIX}/bin
+	@cp -f slock ${DESTDIR}${PREFIX}/bin
+	@chmod 755 ${DESTDIR}${PREFIX}/bin/slock
+	@chmod u+s ${DESTDIR}${PREFIX}/bin/slock
+	@echo installing manual page to ${DESTDIR}${MANPREFIX}/man1
+	@mkdir -p ${DESTDIR}${MANPREFIX}/man1
+	@sed "s/VERSION/${VERSION}/g" <slock.1 >${DESTDIR}${MANPREFIX}/man1/slock.1
+	@chmod 644 ${DESTDIR}${MANPREFIX}/man1/slock.1
+
+uninstall:
+	@echo removing executable file from ${DESTDIR}${PREFIX}/bin
+	@rm -f ${DESTDIR}${PREFIX}/bin/slock
+	@echo removing manual page from ${DESTDIR}${MANPREFIX}/man1
+	@rm -f ${DESTDIR}${MANPREFIX}/man1/slock.1
+
+.PHONY: all options clean dist install uninstall
diff --git a/README b/README
new file mode 100644
index 0000000..dcacd01
--- /dev/null
+++ b/README
@@ -0,0 +1,24 @@
+slock - simple screen locker
+============================
+simple screen locker utility for X.
+
+
+Requirements
+------------
+In order to build slock you need the Xlib header files.
+
+
+Installation
+------------
+Edit config.mk to match your local setup (slock is installed into
+the /usr/local namespace by default).
+
+Afterwards enter the following command to build and install slock
+(if necessary as root):
+
+    make clean install
+
+
+Running slock
+-------------
+Simply invoke the 'slock' command. To get out of it, enter your password.
diff --git a/arg.h b/arg.h
new file mode 100644
index 0000000..0b23c53
--- /dev/null
+++ b/arg.h
@@ -0,0 +1,65 @@
+/*
+ * Copy me if you can.
+ * by 20h
+ */
+
+#ifndef ARG_H__
+#define ARG_H__
+
+extern char *argv0;
+
+/* use main(int argc, char *argv[]) */
+#define ARGBEGIN	for (argv0 = *argv, argv++, argc--;\
+					argv[0] && argv[0][0] == '-'\
+					&& argv[0][1];\
+					argc--, argv++) {\
+				char argc_;\
+				char **argv_;\
+				int brk_;\
+				if (argv[0][1] == '-' && argv[0][2] == '\0') {\
+					argv++;\
+					argc--;\
+					break;\
+				}\
+				for (brk_ = 0, argv[0]++, argv_ = argv;\
+						argv[0][0] && !brk_;\
+						argv[0]++) {\
+					if (argv_ != argv)\
+						break;\
+					argc_ = argv[0][0];\
+					switch (argc_)
+
+/* Handles obsolete -NUM syntax */
+#define ARGNUM				case '0':\
+					case '1':\
+					case '2':\
+					case '3':\
+					case '4':\
+					case '5':\
+					case '6':\
+					case '7':\
+					case '8':\
+					case '9'
+
+#define ARGEND			}\
+			}
+
+#define ARGC()		argc_
+
+#define ARGNUMF()	(brk_ = 1, estrtonum(argv[0], 0, INT_MAX))
+
+#define EARGF(x)	((argv[0][1] == '\0' && argv[1] == NULL)?\
+				((x), abort(), (char *)0) :\
+				(brk_ = 1, (argv[0][1] != '\0')?\
+					(&argv[0][1]) :\
+					(argc--, argv++, argv[0])))
+
+#define ARGF()		((argv[0][1] == '\0' && argv[1] == NULL)?\
+				(char *)0 :\
+				(brk_ = 1, (argv[0][1] != '\0')?\
+					(&argv[0][1]) :\
+					(argc--, argv++, argv[0])))
+
+#define LNGARG()	&argv[0][0]
+
+#endif
diff --git a/config.def.h b/config.def.h
new file mode 100644
index 0000000..9855e21
--- /dev/null
+++ b/config.def.h
@@ -0,0 +1,12 @@
+/* user and group to drop privileges to */
+static const char *user  = "nobody";
+static const char *group = "nogroup";
+
+static const char *colorname[NUMCOLS] = {
+	[INIT] =   "black",     /* after initialization */
+	[INPUT] =  "#005577",   /* during input */
+	[FAILED] = "#CC3333",   /* wrong password */
+};
+
+/* treat a cleared input like a wrong password (color) */
+static const int failonclear = 1;
diff --git a/config.h b/config.h
new file mode 100644
index 0000000..400e4f2
--- /dev/null
+++ b/config.h
@@ -0,0 +1,17 @@
+/* user and group to drop privileges to */
+static const char *user  = "nobody";
+static const char *group = "nogroup";
+
+static const char *colorname[NUMCOLS] = {
+	[INIT] =   "#000000",   /* after initialization */
+	[INPUT] =  "#000000",   /* during input */
+	[FAILED] = "#000000",   /* wrong password */
+};
+
+/* treat a cleared input like a wrong password (color) */
+static const int failonclear = 1;
+const char * fonts[] = {"Source Code Pro:size=24"};
+const char * schemes[] = {"#ffffff", "#000000", "#000000"};
+const int diasize[] = {320, 320};
+const char * lock_message = "Nathan Reiner";
+const char * pass_char = "•";
diff --git a/config.mk b/config.mk
new file mode 100644
index 0000000..4597729
--- /dev/null
+++ b/config.mk
@@ -0,0 +1,34 @@
+# slock version
+VERSION = 1.4
+
+# Customize below to fit your system
+
+# paths
+PREFIX = /usr/local
+MANPREFIX = ${PREFIX}/share/man
+
+X11INC = /usr/X11R6/include
+X11LIB = /usr/X11R6/lib
+FREETPYEINC = /usr/include/freetype2
+FREETYPELIBS = -lfontconfig -lXft
+
+# includes and libs
+INCS = -I. -I/usr/include -I${X11INC} -I${FREETPYEINC}
+LIBS = -L/usr/lib -lc -lcrypt -L${X11LIB} -lX11 -lXext -lXrandr ${FREETYPELIBS}
+
+# flags
+CPPFLAGS = -DVERSION=\"${VERSION}\" -D_DEFAULT_SOURCE -DHAVE_SHADOW_H
+CFLAGS = -std=c99 -pedantic -Wall -Os ${INCS} ${CPPFLAGS}
+LDFLAGS = -s ${LIBS}
+COMPATSRC = explicit_bzero.c util.c drw.c
+
+# On OpenBSD and Darwin remove -lcrypt from LIBS
+#LIBS = -L/usr/lib -lc -L${X11LIB} -lX11 -lXext -lXrandr
+# On *BSD remove -DHAVE_SHADOW_H from CPPFLAGS
+# On NetBSD add -D_NETBSD_SOURCE to CPPFLAGS
+#CPPFLAGS = -DVERSION=\"${VERSION}\" -D_BSD_SOURCE -D_NETBSD_SOURCE
+# On OpenBSD set COMPATSRC to empty
+#COMPATSRC =
+
+# compiler and linker
+CC = cc
diff --git a/drw.c b/drw.c
new file mode 100644
index 0000000..4cdbcbe
--- /dev/null
+++ b/drw.c
@@ -0,0 +1,436 @@
+/* See LICENSE file for copyright and license details. */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <X11/Xlib.h>
+#include <X11/Xft/Xft.h>
+
+#include "drw.h"
+#include "util.h"
+
+#define UTF_INVALID 0xFFFD
+#define UTF_SIZ     4
+
+static const unsigned char utfbyte[UTF_SIZ + 1] = {0x80,    0, 0xC0, 0xE0, 0xF0};
+static const unsigned char utfmask[UTF_SIZ + 1] = {0xC0, 0x80, 0xE0, 0xF0, 0xF8};
+static const long utfmin[UTF_SIZ + 1] = {       0,    0,  0x80,  0x800,  0x10000};
+static const long utfmax[UTF_SIZ + 1] = {0x10FFFF, 0x7F, 0x7FF, 0xFFFF, 0x10FFFF};
+
+static long
+utf8decodebyte(const char c, size_t *i)
+{
+	for (*i = 0; *i < (UTF_SIZ + 1); ++(*i))
+		if (((unsigned char)c & utfmask[*i]) == utfbyte[*i])
+			return (unsigned char)c & ~utfmask[*i];
+	return 0;
+}
+
+static size_t
+utf8validate(long *u, size_t i)
+{
+	if (!BETWEEN(*u, utfmin[i], utfmax[i]) || BETWEEN(*u, 0xD800, 0xDFFF))
+		*u = UTF_INVALID;
+	for (i = 1; *u > utfmax[i]; ++i)
+		;
+	return i;
+}
+
+static size_t
+utf8decode(const char *c, long *u, size_t clen)
+{
+	size_t i, j, len, type;
+	long udecoded;
+
+	*u = UTF_INVALID;
+	if (!clen)
+		return 0;
+	udecoded = utf8decodebyte(c[0], &len);
+	if (!BETWEEN(len, 1, UTF_SIZ))
+		return 1;
+	for (i = 1, j = 1; i < clen && j < len; ++i, ++j) {
+		udecoded = (udecoded << 6) | utf8decodebyte(c[i], &type);
+		if (type)
+			return j;
+	}
+	if (j < len)
+		return 0;
+	*u = udecoded;
+	utf8validate(u, len);
+
+	return len;
+}
+
+Drw *
+drw_create(Display *dpy, int screen, Window root, unsigned int w, unsigned int h)
+{
+	Drw *drw = ecalloc(1, sizeof(Drw));
+
+	drw->dpy = dpy;
+	drw->screen = screen;
+	drw->root = root;
+	drw->w = w;
+	drw->h = h;
+	drw->drawable = XCreatePixmap(dpy, root, w, h, DefaultDepth(dpy, screen));
+	drw->gc = XCreateGC(dpy, root, 0, NULL);
+	XSetLineAttributes(dpy, drw->gc, 1, LineSolid, CapButt, JoinMiter);
+
+	return drw;
+}
+
+void
+drw_resize(Drw *drw, unsigned int w, unsigned int h)
+{
+	if (!drw)
+		return;
+
+	drw->w = w;
+	drw->h = h;
+	if (drw->drawable)
+		XFreePixmap(drw->dpy, drw->drawable);
+	drw->drawable = XCreatePixmap(drw->dpy, drw->root, w, h, DefaultDepth(drw->dpy, drw->screen));
+}
+
+void
+drw_free(Drw *drw)
+{
+	XFreePixmap(drw->dpy, drw->drawable);
+	XFreeGC(drw->dpy, drw->gc);
+	drw_fontset_free(drw->fonts);
+	free(drw);
+}
+
+/* This function is an implementation detail. Library users should use
+ * drw_fontset_create instead.
+ */
+static Fnt *
+xfont_create(Drw *drw, const char *fontname, FcPattern *fontpattern)
+{
+	Fnt *font;
+	XftFont *xfont = NULL;
+	FcPattern *pattern = NULL;
+
+	if (fontname) {
+		/* Using the pattern found at font->xfont->pattern does not yield the
+		 * same substitution results as using the pattern returned by
+		 * FcNameParse; using the latter results in the desired fallback
+		 * behaviour whereas the former just results in missing-character
+		 * rectangles being drawn, at least with some fonts. */
+		if (!(xfont = XftFontOpenName(drw->dpy, drw->screen, fontname))) {
+			fprintf(stderr, "error, cannot load font from name: '%s'\n", fontname);
+			return NULL;
+		}
+		if (!(pattern = FcNameParse((FcChar8 *) fontname))) {
+			fprintf(stderr, "error, cannot parse font name to pattern: '%s'\n", fontname);
+			XftFontClose(drw->dpy, xfont);
+			return NULL;
+		}
+	} else if (fontpattern) {
+		if (!(xfont = XftFontOpenPattern(drw->dpy, fontpattern))) {
+			fprintf(stderr, "error, cannot load font from pattern.\n");
+			return NULL;
+		}
+	} else {
+		die("no font specified.");
+	}
+
+	/* Do not allow using color fonts. This is a workaround for a BadLength
+	 * error from Xft with color glyphs. Modelled on the Xterm workaround. See
+	 * https://bugzilla.redhat.com/show_bug.cgi?id=1498269
+	 * https://lists.suckless.org/dev/1701/30932.html
+	 * https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=916349
+	 * and lots more all over the internet.
+	 */
+	FcBool iscol;
+	if(FcPatternGetBool(xfont->pattern, FC_COLOR, 0, &iscol) == FcResultMatch && iscol) {
+		XftFontClose(drw->dpy, xfont);
+		return NULL;
+	}
+
+	font = ecalloc(1, sizeof(Fnt));
+	font->xfont = xfont;
+	font->pattern = pattern;
+	font->h = xfont->ascent + xfont->descent;
+	font->dpy = drw->dpy;
+
+	return font;
+}
+
+static void
+xfont_free(Fnt *font)
+{
+	if (!font)
+		return;
+	if (font->pattern)
+		FcPatternDestroy(font->pattern);
+	XftFontClose(font->dpy, font->xfont);
+	free(font);
+}
+
+Fnt*
+drw_fontset_create(Drw* drw, const char *fonts[], size_t fontcount)
+{
+	Fnt *cur, *ret = NULL;
+	size_t i;
+
+	if (!drw || !fonts)
+		return NULL;
+
+	for (i = 1; i <= fontcount; i++) {
+		if ((cur = xfont_create(drw, fonts[fontcount - i], NULL))) {
+			cur->next = ret;
+			ret = cur;
+		}
+	}
+	return (drw->fonts = ret);
+}
+
+void
+drw_fontset_free(Fnt *font)
+{
+	if (font) {
+		drw_fontset_free(font->next);
+		xfont_free(font);
+	}
+}
+
+void
+drw_clr_create(Drw *drw, Clr *dest, const char *clrname)
+{
+	if (!drw || !dest || !clrname)
+		return;
+
+	if (!XftColorAllocName(drw->dpy, DefaultVisual(drw->dpy, drw->screen),
+	                       DefaultColormap(drw->dpy, drw->screen),
+	                       clrname, dest))
+		die("error, cannot allocate color '%s'", clrname);
+}
+
+/* Wrapper to create color schemes. The caller has to call free(3) on the
+ * returned color scheme when done using it. */
+Clr *
+drw_scm_create(Drw *drw, const char *clrnames[], size_t clrcount)
+{
+	size_t i;
+	Clr *ret;
+
+	/* need at least two colors for a scheme */
+	if (!drw || !clrnames || clrcount < 2 || !(ret = ecalloc(clrcount, sizeof(XftColor))))
+		return NULL;
+
+	for (i = 0; i < clrcount; i++)
+		drw_clr_create(drw, &ret[i], clrnames[i]);
+	return ret;
+}
+
+void
+drw_setfontset(Drw *drw, Fnt *set)
+{
+	if (drw)
+		drw->fonts = set;
+}
+
+void
+drw_setscheme(Drw *drw, Clr *scm)
+{
+	if (drw)
+		drw->scheme = scm;
+}
+
+void
+drw_rect(Drw *drw, int x, int y, unsigned int w, unsigned int h, int filled, int invert)
+{
+	if (!drw || !drw->scheme)
+		return;
+	XSetForeground(drw->dpy, drw->gc, invert ? drw->scheme[ColBg].pixel : drw->scheme[ColFg].pixel);
+	if (filled)
+		XFillRectangle(drw->dpy, drw->drawable, drw->gc, x, y, w, h);
+	else
+		XDrawRectangle(drw->dpy, drw->drawable, drw->gc, x, y, w - 1, h - 1);
+}
+
+int
+drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, unsigned int lpad, const char *text, int invert)
+{
+	char buf[1024];
+	int ty;
+	unsigned int ew;
+	XftDraw *d = NULL;
+	Fnt *usedfont, *curfont, *nextfont;
+	size_t i, len;
+	int utf8strlen, utf8charlen, render = x || y || w || h;
+	long utf8codepoint = 0;
+	const char *utf8str;
+	FcCharSet *fccharset;
+	FcPattern *fcpattern;
+	FcPattern *match;
+	XftResult result;
+	int charexists = 0;
+
+	if (!drw || (render && !drw->scheme) || !text || !drw->fonts)
+		return 0;
+
+	if (!render) {
+		w = ~w;
+	} else {
+		XSetForeground(drw->dpy, drw->gc, drw->scheme[invert ? ColFg : ColBg].pixel);
+		XFillRectangle(drw->dpy, drw->drawable, drw->gc, x, y, w, h);
+		d = XftDrawCreate(drw->dpy, drw->drawable,
+		                  DefaultVisual(drw->dpy, drw->screen),
+		                  DefaultColormap(drw->dpy, drw->screen));
+		x += lpad;
+		w -= lpad;
+	}
+
+	usedfont = drw->fonts;
+	while (1) {
+		utf8strlen = 0;
+		utf8str = text;
+		nextfont = NULL;
+		while (*text) {
+			utf8charlen = utf8decode(text, &utf8codepoint, UTF_SIZ);
+			for (curfont = drw->fonts; curfont; curfont = curfont->next) {
+				charexists = charexists || XftCharExists(drw->dpy, curfont->xfont, utf8codepoint);
+				if (charexists) {
+					if (curfont == usedfont) {
+						utf8strlen += utf8charlen;
+						text += utf8charlen;
+					} else {
+						nextfont = curfont;
+					}
+					break;
+				}
+			}
+
+			if (!charexists || nextfont)
+				break;
+			else
+				charexists = 0;
+		}
+
+		if (utf8strlen) {
+			drw_font_getexts(usedfont, utf8str, utf8strlen, &ew, NULL);
+			/* shorten text if necessary */
+			for (len = MIN(utf8strlen, sizeof(buf) - 1); len && ew > w; len--)
+				drw_font_getexts(usedfont, utf8str, len, &ew, NULL);
+
+			if (len) {
+				memcpy(buf, utf8str, len);
+				buf[len] = '\0';
+				if (len < utf8strlen)
+					for (i = len; i && i > len - 3; buf[--i] = '.')
+						; /* NOP */
+
+				if (render) {
+					ty = y + (h - usedfont->h) / 2 + usedfont->xfont->ascent;
+					XftDrawStringUtf8(d, &drw->scheme[invert ? ColBg : ColFg],
+					                  usedfont->xfont, x, ty, (XftChar8 *)buf, len);
+				}
+				x += ew;
+				w -= ew;
+			}
+		}
+
+		if (!*text) {
+			break;
+		} else if (nextfont) {
+			charexists = 0;
+			usedfont = nextfont;
+		} else {
+			/* Regardless of whether or not a fallback font is found, the
+			 * character must be drawn. */
+			charexists = 1;
+
+			fccharset = FcCharSetCreate();
+			FcCharSetAddChar(fccharset, utf8codepoint);
+
+			if (!drw->fonts->pattern) {
+				/* Refer to the comment in xfont_create for more information. */
+				die("the first font in the cache must be loaded from a font string.");
+			}
+
+			fcpattern = FcPatternDuplicate(drw->fonts->pattern);
+			FcPatternAddCharSet(fcpattern, FC_CHARSET, fccharset);
+			FcPatternAddBool(fcpattern, FC_SCALABLE, FcTrue);
+			FcPatternAddBool(fcpattern, FC_COLOR, FcFalse);
+
+			FcConfigSubstitute(NULL, fcpattern, FcMatchPattern);
+			FcDefaultSubstitute(fcpattern);
+			match = XftFontMatch(drw->dpy, drw->screen, fcpattern, &result);
+
+			FcCharSetDestroy(fccharset);
+			FcPatternDestroy(fcpattern);
+
+			if (match) {
+				usedfont = xfont_create(drw, NULL, match);
+				if (usedfont && XftCharExists(drw->dpy, usedfont->xfont, utf8codepoint)) {
+					for (curfont = drw->fonts; curfont->next; curfont = curfont->next)
+						; /* NOP */
+					curfont->next = usedfont;
+				} else {
+					xfont_free(usedfont);
+					usedfont = drw->fonts;
+				}
+			}
+		}
+	}
+	if (d)
+		XftDrawDestroy(d);
+
+	return x + (render ? w : 0);
+}
+
+void
+drw_map(Drw *drw, Window win, int x, int y, unsigned int w, unsigned int h)
+{
+	if (!drw)
+		return;
+
+	XCopyArea(drw->dpy, drw->drawable, win, drw->gc, x, y, w, h, x, y);
+	XSync(drw->dpy, False);
+}
+
+unsigned int
+drw_fontset_getwidth(Drw *drw, const char *text)
+{
+	if (!drw || !drw->fonts || !text)
+		return 0;
+	return drw_text(drw, 0, 0, 0, 0, 0, text, 0);
+}
+
+void
+drw_font_getexts(Fnt *font, const char *text, unsigned int len, unsigned int *w, unsigned int *h)
+{
+	XGlyphInfo ext;
+
+	if (!font || !text)
+		return;
+
+	XftTextExtentsUtf8(font->dpy, font->xfont, (XftChar8 *)text, len, &ext);
+	if (w)
+		*w = ext.xOff;
+	if (h)
+		*h = font->h;
+}
+
+Cur *
+drw_cur_create(Drw *drw, int shape)
+{
+	Cur *cur;
+
+	if (!drw || !(cur = ecalloc(1, sizeof(Cur))))
+		return NULL;
+
+	cur->cursor = XCreateFontCursor(drw->dpy, shape);
+
+	return cur;
+}
+
+void
+drw_cur_free(Drw *drw, Cur *cursor)
+{
+	if (!cursor)
+		return;
+
+	XFreeCursor(drw->dpy, cursor->cursor);
+	free(cursor);
+}
diff --git a/drw.h b/drw.h
new file mode 100644
index 0000000..4bcd5ad
--- /dev/null
+++ b/drw.h
@@ -0,0 +1,57 @@
+/* See LICENSE file for copyright and license details. */
+
+typedef struct {
+	Cursor cursor;
+} Cur;
+
+typedef struct Fnt {
+	Display *dpy;
+	unsigned int h;
+	XftFont *xfont;
+	FcPattern *pattern;
+	struct Fnt *next;
+} Fnt;
+
+enum { ColFg, ColBg, ColBorder }; /* Clr scheme index */
+typedef XftColor Clr;
+
+typedef struct {
+	unsigned int w, h;
+	Display *dpy;
+	int screen;
+	Window root;
+	Drawable drawable;
+	GC gc;
+	Clr *scheme;
+	Fnt *fonts;
+} Drw;
+
+/* Drawable abstraction */
+Drw *drw_create(Display *dpy, int screen, Window win, unsigned int w, unsigned int h);
+void drw_resize(Drw *drw, unsigned int w, unsigned int h);
+void drw_free(Drw *drw);
+
+/* Fnt abstraction */
+Fnt *drw_fontset_create(Drw* drw, const char *fonts[], size_t fontcount);
+void drw_fontset_free(Fnt* set);
+unsigned int drw_fontset_getwidth(Drw *drw, const char *text);
+void drw_font_getexts(Fnt *font, const char *text, unsigned int len, unsigned int *w, unsigned int *h);
+
+/* Colorscheme abstraction */
+void drw_clr_create(Drw *drw, Clr *dest, const char *clrname);
+Clr *drw_scm_create(Drw *drw, const char *clrnames[], size_t clrcount);
+
+/* Cursor abstraction */
+Cur *drw_cur_create(Drw *drw, int shape);
+void drw_cur_free(Drw *drw, Cur *cursor);
+
+/* Drawing context manipulation */
+void drw_setfontset(Drw *drw, Fnt *set);
+void drw_setscheme(Drw *drw, Clr *scm);
+
+/* Drawing functions */
+void drw_rect(Drw *drw, int x, int y, unsigned int w, unsigned int h, int filled, int invert);
+int drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, unsigned int lpad, const char *text, int invert);
+
+/* Map functions */
+void drw_map(Drw *drw, Window win, int x, int y, unsigned int w, unsigned int h);
diff --git a/drw.o b/drw.o
new file mode 100644
index 0000000..941460b
--- /dev/null
+++ b/drw.o
diff --git a/explicit_bzero.c b/explicit_bzero.c
new file mode 100644
index 0000000..3e33ca8
--- /dev/null
+++ b/explicit_bzero.c
@@ -0,0 +1,19 @@
+/*	$OpenBSD: explicit_bzero.c,v 1.3 2014/06/21 02:34:26 matthew Exp $ */
+/*
+ * Public domain.
+ * Written by Matthew Dempsky.
+ */
+
+#include <string.h>
+
+__attribute__((weak)) void
+__explicit_bzero_hook(void *buf, size_t len)
+{
+}
+
+void
+explicit_bzero(void *buf, size_t len)
+{
+	memset(buf, 0, len);
+	__explicit_bzero_hook(buf, len);
+}
diff --git a/explicit_bzero.o b/explicit_bzero.o
new file mode 100644
index 0000000..d98c7e9
--- /dev/null
+++ b/explicit_bzero.o
diff --git a/slock b/slock
new file mode 100755
index 0000000..1e6390b
--- /dev/null
+++ b/slock
diff --git a/slock.1 b/slock.1
new file mode 100644
index 0000000..82cdcd6
--- /dev/null
+++ b/slock.1
@@ -0,0 +1,39 @@
+.Dd 2016-08-23
+.Dt SLOCK 1
+.Sh NAME
+.Nm slock
+.Nd simple X screen locker
+.Sh SYNOPSIS
+.Nm
+.Op Fl v
+.Op Ar cmd Op Ar arg ...
+.Sh DESCRIPTION
+.Nm
+is a simple X screen locker. If provided,
+.Ar cmd Op Ar arg ...
+is executed after the screen has been locked.
+.Sh OPTIONS
+.Bl -tag -width Ds
+.It Fl v
+Print version information to stdout and exit.
+.El
+.Sh SECURITY CONSIDERATIONS
+To make sure a locked screen can not be bypassed by switching VTs
+or killing the X server with Ctrl+Alt+Backspace, it is recommended
+to disable both in
+.Xr xorg.conf 5
+for maximum security:
+.Bd -literal -offset left
+Section "ServerFlags"
+	Option "DontVTSwitch" "True"
+	Option "DontZap"      "True"
+EndSection
+.Ed
+.Sh EXAMPLES
+$
+.Nm
+/usr/sbin/s2ram
+.Sh CUSTOMIZATION
+.Nm
+can be customized by creating a custom config.h from config.def.h and
+(re)compiling the source code. This keeps it fast, secure and simple.
diff --git a/slock.c b/slock.c
new file mode 100644
index 0000000..0ec5b18
--- /dev/null
+++ b/slock.c
@@ -0,0 +1,435 @@
+/* See LICENSE file for license details. */
+#define _XOPEN_SOURCE 500
+#if HAVE_SHADOW_H
+#include <shadow.h>
+#endif
+
+#include <ctype.h>
+#include <errno.h>
+#include <grp.h>
+#include <pwd.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <X11/extensions/Xrandr.h>
+#include <X11/keysym.h>
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+#include <X11/Xft/Xft.h>
+
+#include "arg.h"
+#include "util.h"
+#include "drw.h"
+
+char *argv0;
+
+enum {
+	INIT,
+	INPUT,
+	FAILED,
+	NUMCOLS
+};
+
+struct lock {
+	int screen;
+	Window root, win;
+	Pixmap pmap;
+	unsigned long colors[NUMCOLS];
+};
+
+struct xrandr {
+	int active;
+	int evbase;
+	int errbase;
+};
+
+#include "config.h"
+
+
+#ifdef __linux__
+#include <fcntl.h>
+#include <linux/oom.h>
+
+static void
+dontkillme(void)
+{
+	FILE *f;
+	const char oomfile[] = "/proc/self/oom_score_adj";
+
+	if (!(f = fopen(oomfile, "w"))) {
+		if (errno == ENOENT)
+			return;
+		die("slock: fopen %s: %s\n", oomfile, strerror(errno));
+	}
+	fprintf(f, "%d", OOM_SCORE_ADJ_MIN);
+	if (fclose(f)) {
+		if (errno == EACCES)
+			die("slock: unable to disable OOM killer. "
+			    "Make sure to suid or sgid slock.\n");
+		else
+			die("slock: fclose %s: %s\n", oomfile, strerror(errno));
+	}
+}
+#endif
+
+static const char *
+gethash(void)
+{
+	const char *hash;
+	struct passwd *pw;
+
+	/* Check if the current user has a password entry */
+	errno = 0;
+	if (!(pw = getpwuid(getuid()))) {
+		if (errno)
+			die("slock: getpwuid: %s\n", strerror(errno));
+		else
+			die("slock: cannot retrieve password entry\n");
+	}
+	hash = pw->pw_passwd;
+
+#if HAVE_SHADOW_H
+	if (!strcmp(hash, "x")) {
+		struct spwd *sp;
+		if (!(sp = getspnam(pw->pw_name)))
+			die("slock: getspnam: cannot retrieve shadow entry. "
+			    "Make sure to suid or sgid slock.\n");
+		hash = sp->sp_pwdp;
+	}
+#else
+	if (!strcmp(hash, "*")) {
+#ifdef __OpenBSD__
+		if (!(pw = getpwuid_shadow(getuid())))
+			die("slock: getpwnam_shadow: cannot retrieve shadow entry. "
+			    "Make sure to suid or sgid slock.\n");
+		hash = pw->pw_passwd;
+#else
+		die("slock: getpwuid: cannot retrieve shadow entry. "
+		    "Make sure to suid or sgid slock.\n");
+#endif /* __OpenBSD__ */
+	}
+#endif /* HAVE_SHADOW_H */
+
+	return hash;
+}
+
+static void
+readpw(Display *dpy, struct xrandr *rr, struct lock **locks, int nscreens,
+       const char *hash)
+{
+	XRRScreenChangeNotifyEvent *rre;
+	char buf[32], passwd[256], *inputhash;
+	int num, screen, running, failure, oldc;
+	unsigned int len, color;
+	KeySym ksym;
+	XEvent ev;
+
+	len = 0;
+	running = 1;
+	failure = 0;
+	oldc = INIT;
+
+	XRRScreenResources * scr;
+	XRRCrtcInfo * crtc_info;
+	
+	scr = XRRGetScreenResources(dpy, locks[0]->win);
+	crtc_info = XRRGetCrtcInfo(dpy, scr, scr->crtcs[0]);
+	int w_pos[] = { (crtc_info->width - diasize[0]) / 2, (crtc_info->height - diasize[1]) / 2 };
+
+	int w_len[] = {diasize[0] + w_pos[0], diasize[1] + w_pos[1]};
+	
+	Drw * drw = drw_create(dpy, locks[0]->screen, locks[0]->win, crtc_info->width, crtc_info->height);
+	Clr * scm = drw_scm_create(drw, schemes, 3);
+	Fnt * font = drw_fontset_create(drw, fonts, 1);
+	drw_setfontset(drw, font);
+	drw_setscheme(drw, scm);
+
+	int l_size = drw_fontset_getwidth(drw, lock_message);
+
+	int t_pos[] = {(diasize[0] / 2) - (l_size / 2) + w_pos[0], w_pos[1]};
+	int t_len[] = {diasize[0] + w_pos[0], w_pos[1] / 3};
+
+	drw_text(drw, t_pos[0], t_pos[1], t_len[0], t_len[1], 0, lock_message, 0);
+	drw_map(drw, locks[0]->win, 0, 0, crtc_info->width, crtc_info->height);
+
+
+	while (running && !XNextEvent(dpy, &ev)) {
+		if (ev.type == KeyPress) {
+			explicit_bzero(&buf, sizeof(buf));
+			num = XLookupString(&ev.xkey, buf, sizeof(buf), &ksym, 0);
+			if (IsKeypadKey(ksym)) {
+				if (ksym == XK_KP_Enter)
+					ksym = XK_Return;
+				else if (ksym >= XK_KP_0 && ksym <= XK_KP_9)
+					ksym = (ksym - XK_KP_0) + XK_0;
+			}
+			if (IsFunctionKey(ksym) ||
+			    IsKeypadKey(ksym) ||
+			    IsMiscFunctionKey(ksym) ||
+			    IsPFKey(ksym) ||
+			    IsPrivateKeypadKey(ksym))
+				continue;
+			switch (ksym) {
+			case XK_Return:
+				passwd[len] = '\0';
+				errno = 0;
+				if (!(inputhash = crypt(passwd, hash)))
+					fprintf(stderr, "slock: crypt: %s\n", strerror(errno));
+				else
+					running = !!strcmp(inputhash, hash);
+				if (running) {
+					XBell(dpy, 100);
+					failure = 1;
+				}
+				explicit_bzero(&passwd, sizeof(passwd));
+				len = 0;
+				break;
+			case XK_Escape:
+				explicit_bzero(&passwd, sizeof(passwd));
+				len = 0;
+				break;
+			case XK_BackSpace:
+				if (len)
+					passwd[--len] = '\0';
+				break;
+			default:
+				if (num && !iscntrl((int)buf[0]) &&
+				    (len + num < sizeof(passwd))) {
+					memcpy(passwd + len, buf, num);
+					len += num;
+				}
+				break;
+			}
+			color = len ? INPUT : ((failure || failonclear) ? FAILED : INIT);
+			if (running && oldc != color) {
+				for (screen = 0; screen < nscreens; screen++) {
+					XSetWindowBackground(dpy,
+					                     locks[screen]->win,
+					                     locks[screen]->colors[color]);
+					XClearWindow(dpy, locks[screen]->win);
+				}
+				oldc = color;
+			}
+
+			drw_rect(drw, 0, crtc_info->height - w_pos[1], crtc_info->width, w_len[1], 1, 1);
+
+			if (!failure) {
+
+				for (int i = 0; i < strlen(passwd); i++) {
+					drw_text(drw,
+							(i * 15) + (crtc_info->width / 2 - strlen(passwd) * 15 / 2),
+							w_pos[1] + diasize[1],
+							w_len[0],
+							diasize[1],
+							0,
+							pass_char,
+							0
+					);
+				}
+
+			} else {
+				drw_text(drw, t_pos[0], w_pos[1] + diasize[1], w_len[0], diasize[1], 0, "\u274c", 0);
+				failure = 0;
+			}
+
+			drw_map(drw, locks[0]->win, 0, 0, crtc_info->width, crtc_info->height);
+
+		} else if (rr->active && ev.type == rr->evbase + RRScreenChangeNotify) {
+			rre = (XRRScreenChangeNotifyEvent*)&ev;
+			for (screen = 0; screen < nscreens; screen++) {
+				if (locks[screen]->win == rre->window) {
+					if (rre->rotation == RR_Rotate_90 ||
+					    rre->rotation == RR_Rotate_270)
+						XResizeWindow(dpy, locks[screen]->win,
+						              rre->height, rre->width);
+					else
+						XResizeWindow(dpy, locks[screen]->win,
+						              rre->width, rre->height);
+					XClearWindow(dpy, locks[screen]->win);
+					break;
+				}
+			}
+		} else {
+			for (screen = 0; screen < nscreens; screen++)
+				XRaiseWindow(dpy, locks[screen]->win);
+		}
+	}
+}
+
+static struct lock *
+lockscreen(Display *dpy, struct xrandr *rr, int screen)
+{
+	char curs[] = {0, 0, 0, 0, 0, 0, 0, 0};
+	int i, ptgrab, kbgrab;
+	struct lock *lock;
+	XColor color, dummy;
+	XSetWindowAttributes wa;
+	Cursor invisible;
+
+	if (dpy == NULL || screen < 0 || !(lock = malloc(sizeof(struct lock))))
+		return NULL;
+
+	lock->screen = screen;
+	lock->root = RootWindow(dpy, lock->screen);
+
+	for (i = 0; i < NUMCOLS; i++) {
+		XAllocNamedColor(dpy, DefaultColormap(dpy, lock->screen),
+		                 colorname[i], &color, &dummy);
+		lock->colors[i] = color.pixel;
+	}
+
+	/* init */
+	wa.override_redirect = 1;
+	wa.background_pixel = lock->colors[INIT];
+	lock->win = XCreateWindow(dpy, lock->root, 0, 0,
+	                          DisplayWidth(dpy, lock->screen),
+	                          DisplayHeight(dpy, lock->screen),
+	                          0, DefaultDepth(dpy, lock->screen),
+	                          CopyFromParent,
+	                          DefaultVisual(dpy, lock->screen),
+	                          CWOverrideRedirect | CWBackPixel, &wa);
+	lock->pmap = XCreateBitmapFromData(dpy, lock->win, curs, 8, 8);
+	invisible = XCreatePixmapCursor(dpy, lock->pmap, lock->pmap,
+	                                &color, &color, 0, 0);
+	XDefineCursor(dpy, lock->win, invisible);
+
+	/* Try to grab mouse pointer *and* keyboard for 600ms, else fail the lock */
+	for (i = 0, ptgrab = kbgrab = -1; i < 6; i++) {
+		if (ptgrab != GrabSuccess) {
+			ptgrab = XGrabPointer(dpy, lock->root, False,
+			                      ButtonPressMask | ButtonReleaseMask |
+			                      PointerMotionMask, GrabModeAsync,
+			                      GrabModeAsync, None, invisible, CurrentTime);
+		}
+		if (kbgrab != GrabSuccess) {
+			kbgrab = XGrabKeyboard(dpy, lock->root, True,
+			                       GrabModeAsync, GrabModeAsync, CurrentTime);
+		}
+
+		/* input is grabbed: we can lock the screen */
+		if (ptgrab == GrabSuccess && kbgrab == GrabSuccess) {
+			XMapRaised(dpy, lock->win);
+			if (rr->active)
+				XRRSelectInput(dpy, lock->win, RRScreenChangeNotifyMask);
+
+			XSelectInput(dpy, lock->root, SubstructureNotifyMask);
+			return lock;
+		}
+
+		/* retry on AlreadyGrabbed but fail on other errors */
+		if ((ptgrab != AlreadyGrabbed && ptgrab != GrabSuccess) ||
+		    (kbgrab != AlreadyGrabbed && kbgrab != GrabSuccess))
+			break;
+
+		usleep(100000);
+	}
+
+	/* we couldn't grab all input: fail out */
+	if (ptgrab != GrabSuccess)
+		fprintf(stderr, "slock: unable to grab mouse pointer for screen %d\n",
+		        screen);
+	if (kbgrab != GrabSuccess)
+		fprintf(stderr, "slock: unable to grab keyboard for screen %d\n",
+		        screen);
+	return NULL;
+}
+
+static void
+usage(void)
+{
+	die("usage: slock [-v] [cmd [arg ...]]\n");
+}
+
+int
+main(int argc, char **argv) {
+	struct xrandr rr;
+	struct lock **locks;
+	struct passwd *pwd;
+	struct group *grp;
+	uid_t duid;
+	gid_t dgid;
+	const char *hash;
+	Display *dpy;
+	int s, nlocks, nscreens;
+
+	ARGBEGIN {
+	case 'v':
+		fprintf(stderr, "slock-"VERSION"\n");
+		return 0;
+	default:
+		usage();
+	} ARGEND
+
+	/* validate drop-user and -group */
+	errno = 0;
+	if (!(pwd = getpwnam(user)))
+		die("slock: getpwnam %s: %s\n", user,
+		    errno ? strerror(errno) : "user entry not found");
+	duid = pwd->pw_uid;
+	errno = 0;
+	if (!(grp = getgrnam(group)))
+		die("slock: getgrnam %s: %s\n", group,
+		    errno ? strerror(errno) : "group entry not found");
+	dgid = grp->gr_gid;
+
+#ifdef __linux__
+	dontkillme();
+#endif
+
+	hash = gethash();
+	errno = 0;
+	if (!crypt("", hash))
+		die("slock: crypt: %s\n", strerror(errno));
+
+	if (!(dpy = XOpenDisplay(NULL)))
+		die("slock: cannot open display\n");
+
+	/* drop privileges */
+	if (setgroups(0, NULL) < 0)
+		die("slock: setgroups: %s\n", strerror(errno));
+	if (setgid(dgid) < 0)
+		die("slock: setgid: %s\n", strerror(errno));
+	if (setuid(duid) < 0)
+		die("slock: setuid: %s\n", strerror(errno));
+
+	/* check for Xrandr support */
+	rr.active = XRRQueryExtension(dpy, &rr.evbase, &rr.errbase);
+
+	/* get number of screens in display "dpy" and blank them */
+	nscreens = ScreenCount(dpy);
+	if (!(locks = calloc(nscreens, sizeof(struct lock *))))
+		die("slock: out of memory\n");
+	for (nlocks = 0, s = 0; s < nscreens; s++) {
+		if ((locks[s] = lockscreen(dpy, &rr, s)) != NULL)
+			nlocks++;
+		else
+			break;
+	}
+	XSync(dpy, 0);
+
+	/* did we manage to lock everything? */
+	if (nlocks != nscreens)
+		return 1;
+
+	/* run post-lock command */
+	if (argc > 0) {
+		switch (fork()) {
+		case -1:
+			die("slock: fork failed: %s\n", strerror(errno));
+		case 0:
+			if (close(ConnectionNumber(dpy)) < 0)
+				die("slock: close: %s\n", strerror(errno));
+			execvp(argv[0], argv);
+			fprintf(stderr, "slock: execvp %s: %s\n", argv[0], strerror(errno));
+			_exit(1);
+		}
+	}
+
+	/* everything is now blank. Wait for the correct password */
+	readpw(dpy, &rr, locks, nscreens, hash);
+
+	return 0;
+}
diff --git a/slock.o b/slock.o
new file mode 100644
index 0000000..b25eddc
--- /dev/null
+++ b/slock.o
diff --git a/util.c b/util.c
new file mode 100644
index 0000000..fe044fc
--- /dev/null
+++ b/util.c
@@ -0,0 +1,35 @@
+/* See LICENSE 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);
+}
diff --git a/util.h b/util.h
new file mode 100644
index 0000000..e4930bf
--- /dev/null
+++ b/util.h
@@ -0,0 +1,10 @@
+/* See LICENSE file for copyright and license details. */
+
+#define MAX(A, B)               ((A) > (B) ? (A) : (B))
+#define MIN(A, B)               ((A) < (B) ? (A) : (B))
+#define BETWEEN(X, A, B)        ((A) <= (X) && (X) <= (B))
+
+void die(const char *fmt, ...);
+void *ecalloc(size_t nmemb, size_t size);
+#undef explicit_bzero
+void explicit_bzero(void *, size_t);
diff --git a/util.o b/util.o
new file mode 100644
index 0000000..4607dbd
--- /dev/null
+++ b/util.o