git.y1.nz

commit ce1a7bc6685440a31cd95da8b8882dcee004b122
Author: Emma Weaver <emma@waeaves.com>
Date:   Sat, 11 Apr 2026 13:04:44 -0400

basic bmp screenshots

Diffstat:
A
.gitignore
8
++++++++
A
LICENSE
38
++++++++++++++++++++++++++++++++++++++
A
Makefile
29
+++++++++++++++++++++++++++++
A
README
8
++++++++
A
bmp.c
110
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
A
bmp.h
27
+++++++++++++++++++++++++++
A
config.default.h
5
+++++
A
config.mk
28
++++++++++++++++++++++++++++
A
main.c
94
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

9 files changed, 347 insertions(+), 0 deletions(-)
diff --git a/.gitignore b/.gitignore
@@ -0,0 +1,8 @@
+grabs
+
+config.h
+
+**.o
+**.swp
+**.bmp
+
diff --git a/LICENSE b/LICENSE
@@ -0,0 +1,38 @@
+MIT/X Consortium License
+
+© 2010-2026 Hiltjo Posthuma <hiltjo@codemadness.org>
+© 2006-2019 Anselm R Garbe <anselm@garbe.ca>
+© 2006-2009 Jukka Salmi <jukka at salmi dot ch>
+© 2006-2007 Sander van Dijk <a dot h dot vandijk at gmail dot com>
+© 2007-2011 Peter Hartlich <sgkkr at hartlich dot com>
+© 2007-2009 Szabolcs Nagy <nszabolcs at gmail dot com>
+© 2007-2009 Christof Musik <christof at sendfax dot de>
+© 2007-2009 Premysl Hruby <dfenze at gmail dot com>
+© 2007-2008 Enno Gottox Boland <gottox at s01 dot de>
+© 2008 Martin Hurton <martin dot hurton at gmail dot com>
+© 2008 Neale Pickett <neale dot woozle dot org>
+© 2009 Mate Nagy <mnagy at port70 dot net>
+© 2010-2012 Connor Lane Smith <cls@lubutu.com>
+© 2011 Christoph Lohmann <20h@r-36.net>
+© 2015-2016 Quentin Rameau <quinq@fifth.space>
+© 2015-2016 Eric Pruitt <eric.pruitt@gmail.com>
+© 2016-2017 Markus Teich <markus.teich@stusta.mhn.de>
+© 2020-2022 Chris Down <chris@chrisdown.name>
+
+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
@@ -0,0 +1,29 @@
+
+include config.mk
+
+grabs: bmp.c bmp.h
+grabs: config.h
+grabs: main.c
+	cc main.c ${CFLAGS} ${LDFLAGS} -o grabs 
+
+config.h: config.default.h
+	cp config.default.h config.h
+
+# dist: clean
+# 	mkdir -p st-$(VERSION)
+# 	cp -R FAQ LEGACY TODO LICENSE Makefile README config.mk\
+# 		config.def.h st.info st.1 arg.h st.h win.h $(SRC)\
+# 		st-$(VERSION)
+# 	tar -cf - st-$(VERSION) | gzip > st-$(VERSION).tar.gz
+# 	rm -rf st-$(VERSION)
+# 
+# install: st
+# 	mkdir -p $(DESTDIR)$(PREFIX)/bin
+# 	cp -f st $(DESTDIR)$(PREFIX)/bin
+# 	chmod 755 $(DESTDIR)$(PREFIX)/bin/st
+# 	mkdir -p $(DESTDIR)$(MANPREFIX)/man1
+# 	chmod 644 $(DESTDIR)$(MANPREFIX)/man1/st.1
+# 	tic -sx st.info
+
+.PHONY: test bmp clean
+
diff --git a/README b/README
@@ -0,0 +1,8 @@
+
+Grabs is a minimal screenshot program based on X11. 
+
+TODO:
+ - add vim-style keyboard controls and GUI for that
+ - add "install" and "clean" directives like what dwm and st have
+ - figure out a space-efficient way to record video
+
diff --git a/bmp.c b/bmp.c
@@ -0,0 +1,110 @@
+/* Originally retrieved from github.com/yunhao-qian/save-bmp */
+/* Adapted by Emma Weaver on 26-04-16. */
+
+#ifndef WRITE_BMP_IMPLEMENT
+#define WRITE_BMP_IMPLEMENT
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+
+#define WRITE_BMP_U16(offset, value) \
+	header[offset + 0] = 0xff & (value >> 0); \
+	header[offset + 1] = 0xff & (value >> 8);
+
+#define WRITE_BMP_U32(offset, value) \
+	header[offset + 0] = 0xff & (value >> 0); \
+	header[offset + 1] = 0xff & (value >> 8); \
+	header[offset + 2] = 0xff & (value >> 16); \
+	header[offset + 3] = 0xff & (value >> 24);
+
+#define WRITE_SAFE(value) \
+	if (fputc(value, stream) == EOF) \
+		WRITE_BMP_RETURN(WRITE_BMP_WRITE_ERROR);
+
+#define WRITE_BMP_RETURN(code) \
+	{ \
+		fclose(stream); \
+		return (code); \
+	}
+
+enum write_bmp_status
+write_bmp(
+	FILE * const stream,
+	const uint8_t *image,
+	uint32_t width,
+	uint32_t height
+)
+{
+	uint32_t padding = (width * 3) % 4 == 0 ? 0 : 4 - (width * 3) % 4;
+	const uint64_t bf_size = ((uint64_t) width * 3 + padding) * height + 54;
+	uint8_t header[54] = {'B', 'M'};
+	const uint32_t bi_height = ~height + 1;
+
+	if (width == 0 || height == 0)
+		return WRITE_BMP_SIZE_IS_ZERO;
+
+	if (width > 0x55555542 || height > 0x3ffffff2)
+		return WRITE_BMP_SIZE_TOO_BIG;
+
+	if (bf_size > 0xffffffff)
+		return WRITE_BMP_SIZE_TOO_BIG;
+
+	WRITE_BMP_U32(2, bf_size);	/* bf_size */
+	WRITE_BMP_U32(10, 54);		/* bf_off_bits */
+	WRITE_BMP_U32(14, 40);		/* bi_size */
+	WRITE_BMP_U32(18, width);	/* bi_width */
+	WRITE_BMP_U32(22, bi_height);	/* bi_height */
+	WRITE_BMP_U16(26, 1);		/* bi_planes */
+	WRITE_BMP_U16(28, 24);		/* bi_bit_count */
+	WRITE_BMP_U32(38, 2835);		/* bi_x_pels_per_meter */
+	WRITE_BMP_U32(42, 2835);		/* bi_y_pels_per_meter */
+
+	if (fwrite(header, 54, 1, stream) == 0)
+		WRITE_BMP_RETURN(WRITE_BMP_WRITE_ERROR);
+
+	{
+		uint32_t x = 0, y = 0;
+		for (;;) {
+			if (x < width) {
+				WRITE_SAFE(image[2]);
+				WRITE_SAFE(image[1]);
+				WRITE_SAFE(image[0]);
+				image += 3;
+			} else {
+				WRITE_SAFE(0);
+			}
+
+			x++;
+			if (x >= width + padding) {
+				x = 0;
+				y++;
+			}
+			if (y >= height)
+				break;	
+		}
+	}
+
+	WRITE_BMP_RETURN(WRITE_BMP_SUCCESS);
+}
+
+const char *
+get_bmp_status_message(enum write_bmp_status status)
+{
+	switch (status) {
+	case WRITE_BMP_SUCCESS:
+		return "Success";
+	case WRITE_BMP_SIZE_IS_ZERO:
+		return "Error saving image: image size is zero";
+	case WRITE_BMP_SIZE_TOO_BIG:
+		return "Error saving image: image size is too big";
+	case WRITE_BMP_CANT_OPEN_FILE:
+	case WRITE_BMP_WRITE_ERROR:
+		return strerror(errno);
+	default:
+		return "Unknown status code";
+	}
+}
+
+#endif /* WRITE_BMP_IMPLEMENT */
diff --git a/bmp.h b/bmp.h
@@ -0,0 +1,27 @@
+/* Originally retrieved from github.com/yunhao-qian/save-bmp */
+/* Adapted by Emma Weaver on 26-04-16. */
+
+#ifndef SAVE_BMP_INCLUDE
+#define SAVE_BMP_INCLUDE
+
+#include <stdint.h>
+
+
+enum write_bmp_status {
+	WRITE_BMP_SUCCESS,
+	WRITE_BMP_SIZE_IS_ZERO,
+	WRITE_BMP_SIZE_TOO_BIG,
+	WRITE_BMP_CANT_OPEN_FILE,
+	WRITE_BMP_WRITE_ERROR
+};
+
+enum write_bmp_status write_bmp(
+	FILE * const stream,
+	const uint8_t * image,
+	uint32_t width,
+	uint32_t height
+);
+
+const char * get_bmp_status_message(enum write_bmp_status status);
+
+#endif /* SAVE_BMP_INCLUDE */
diff --git a/config.default.h b/config.default.h
@@ -0,0 +1,5 @@
+
+/* grabs will segfault if you try to take a screenshot larger than this. */
+#define MAX_SCREEN_WIDTH 1366
+#define MAX_SCREEN_HEIGHT 768
+
diff --git a/config.mk b/config.mk
@@ -0,0 +1,28 @@
+# grabs version
+VERSION = 1.0
+
+# Customize below to fit your system
+
+# paths
+PREFIX = /usr/local
+MANPREFIX = ${PREFIX}/share/man
+
+X11INC = /usr/X11R6/include
+X11LIB = /usr/X11R6/lib
+
+# includes and libs
+INCS = -I${X11INC}
+LIBS = -L${X11LIB} -lX11
+
+# flags
+CPPFLAGS = -D_DEFAULT_SOURCE -D_BSD_SOURCE -D_XOPEN_SOURCE=700L -DVERSION=\"${VERSION}\"
+#CFLAGS   = -g -std=c99 -pedantic -Wall -O0 ${INCS} ${CPPFLAGS}
+CFLAGS   = -std=c99 -pedantic -Wall -Wno-deprecated-declarations -Os ${INCS} ${CPPFLAGS}
+LDFLAGS  = ${LIBS}
+
+# Solaris
+#CFLAGS = -fast ${INCS} -DVERSION=\"${VERSION}\"
+#LDFLAGS = ${LIBS}
+
+# compiler and linker
+CC = cc
diff --git a/main.c b/main.c
@@ -0,0 +1,94 @@
+#include <stdio.h>
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+#include <stdlib.h>
+#include <limits.h>
+
+#include "config.h"
+#include "bmp.h"
+#include "bmp.c"
+
+#define CANCEL(message) { fprintf(stderr, (message)); exit(1); }
+
+
+uint8_t image_buffer[3 * MAX_SCREEN_WIDTH * MAX_SCREEN_HEIGHT];
+
+int
+stoi(char * arg)
+{
+	char * endptr;
+	int ret;
+	ret = strtol(arg, &endptr, 10);
+	if (* endptr != '\0' || ret > INT_MAX || ret < INT_MIN)
+		CANCEL("Couldn't parse arguments." "\n");
+	return ret;
+}
+
+int
+main(int argc, char * argv[])
+{
+	XImage * ximage;
+	XWindowAttributes wa;
+	Display * display;
+	Window window;
+	int start_x = 0, start_y = 0, width, height;
+
+	display = XOpenDisplay(NULL);
+	if (display == NULL)
+		CANCEL("Couldn't open display." "\n");
+
+	window = RootWindow(display, DefaultScreen(display));
+
+	if (argc == 1) {
+		int get_result = XGetWindowAttributes(display, window, &wa);
+		if (get_result == 0)
+			CANCEL("XGetWindowAttributes failed." "\n");
+		width = wa.width;
+		height = wa.height;
+	} else if (argc == 5) {
+		start_x = stoi(argv[1]);
+		start_y = stoi(argv[2]);
+		width = stoi(argv[3]);
+		height = stoi(argv[4]);
+	} else {
+		CANCEL(
+			"grabs [x y w h]" "\n" \
+			"Minimal screenshot utility." "\n"
+		);
+	}
+
+	ximage = XGetImage(
+		display, window,
+		start_x, start_y, width, height,
+		AllPlanes, ZPixmap
+	);
+	
+	{
+		int x = 0, y = 0;
+		long pixel;
+		uint8_t * buffer_index = image_buffer;
+
+		for (;;) {
+			pixel = XGetPixel(ximage, x, y);
+
+			*buffer_index++ = (pixel & ximage->red_mask) >> 16;
+			*buffer_index++ = (pixel & ximage->green_mask) >> 8;
+			*buffer_index++ = pixel & ximage->blue_mask;
+
+			x++;
+			if (x >= width) {
+				x = 0;
+				y++;
+			}
+			if (y >= height) 
+				break;
+		}
+	}
+
+	const int status = write_bmp(stdout, image_buffer, width, height);
+	if (status != 0)
+		CANCEL(get_bmp_status_message(status));
+
+	return 1;
+}
+

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