build a shared library and rework parts of the code

8 files changed, 496 insertions, 401 deletions

diff --git a/Makefile b/Makefile
index 9e29586..f46bef1 100644
--- a/Makefile
+++ b/Makefile
@@ -1,41 +1,46 @@
 # cqrlogo - CGI QR-Code logo for web services
 
-PREFIX	:= /usr
-LIBDIR	:= $(PREFIX)/lib
+# pathes
+PREFIX		:= /usr
 APACHECONF	:= /etc/apache/conf/extra/
 LIGHTTPDCONF	:= /etc/lighttpd/conf.d/
+# commands
 CC	:= gcc
-MD	:= markdown
-INSTALL	:= install
 CP	:= cp
+FILE	:= file
+GREP	:= grep
+INSTALL	:= install
+LN	:= ln
+MD	:= markdown
 RM	:= rm
-ZBARIMG	:= zbarimg
 SED	:= sed
-GREP	:= grep
-FILE	:= file
+ZBARIMG	:= zbarimg
+# flags
 CFLAGS	+= -O2 -Wall -Werror
-CFLAGS	+= -liniparser
-CFLAGS	+= $(shell pkg-config --cflags --libs libpng)
-CFLAGS	+= $(shell pkg-config --cflags --libs zlib)
-CFLAGS	+= $(shell pkg-config --cflags --libs libqrencode)
+# calls to compiled binary files
+CQRLOGO_CGI	+= LD_LIBRARY_PATH=lib/ ./cqrlogo.cgi
+CQRLOGO_FCGI	+= LD_LIBRARY_PATH=lib/ ./cqrlogo.fcgi
 # this is just a fallback in case you do not use git but downloaded
 # a release tarball...
 VERSION := 0.4.0
 
-all: cqrlogo.cgi cqrlogo.fcgi README.html cqrlogo.png
+all: libcqrlogo cqrlogo.cgi cqrlogo.fcgi README.html cqrlogo.png
+
+libcqrlogo: lib/libcqrlogo.c lib/libcqrlogo.h config.h version.h
+	$(MAKE) -C lib
 
-cqrlogo.cgi: cqrlogo.c config.h version.h
-	$(CC) $(CFLAGS) $(LDFLAGS) -DHAVE_FCGI=0 -o cqrlogo.cgi cqrlogo.c
+cqrlogo.cgi: libcqrlogo cqrlogo.c cqrlogo.h config.h version.h
+	$(CC) -lcqrlogo -Llib/ -Ilib/ $(LDFLAGS) -DHAVE_FCGI=0 -o cqrlogo.cgi cqrlogo.c
 
-cqrlogo.fcgi: cqrlogo.c config.h version.h
-	$(CC) $(CFLAGS) -lfcgi $(LDFLAGS) -DHAVE_FCGI=1 -o cqrlogo.fcgi cqrlogo.c
+cqrlogo.fcgi: libcqrlogo cqrlogo.c cqrlogo.h config.h version.h
+	$(CC) -lcqrlogo -Llib/ -Ilib/ -lfcgi $(LDFLAGS) -DHAVE_FCGI=1 -o cqrlogo.fcgi cqrlogo.c
 
 version.h: $(wildcard .git/HEAD .git/index .git/refs/tags/*) Makefile
 	echo "#ifndef VERSION" > $@
 	echo "#define VERSION \"$(shell git describe --tags --long 2>/dev/null || echo ${VERSION})\"" >> $@
 	echo "#endif" >> $@
 
-config.h:
+config.h: config.def.h
 	$(CP) config.def.h config.h
 
 README.html: README.md
@@ -43,21 +48,24 @@ README.html: README.md
 
 cqrlogo.png: cqrlogo.cgi
 	SERVER_NAME="github.com" HTTP_REFERER="https://github.com/eworm-de/cqrlogo" \
-		    QUERY_STRING='scale=4' \
-		    ./cqrlogo.cgi | $(SED) '1,/^$$/d' > cqrlogo.png
+		QUERY_STRING='scale=4' \
+		$(CQRLOGO_CGI) | $(SED) '1,/^$$/d' > cqrlogo.png
 
 install: install-bin install-config install-doc
 
-install-bin: cqrlogo.cgi cqrlogo.fcgi
-	$(INSTALL) -D -m0755 cqrlogo.cgi $(DESTDIR)$(LIBDIR)/cqrlogo/cqrlogo.cgi
-	$(INSTALL) -D -m0755 cqrlogo.fcgi $(DESTDIR)$(LIBDIR)/cqrlogo/cqrlogo.fcgi
+install-bin: libcqrlogo lib/libcqrlogo.h cqrlogo.cgi cqrlogo.fcgi cqrlogo.conf
+	$(INSTALL) -D -m0755 lib/libcqrlogo.so.$(SOVERSION) $(DESTDIR)$(PREFIX)/lib/libcqrlogo.so.$(SOVERSION)
+	$(INSTALL) -D -m0755 lib/libcqrlogo.h $(DESTDIR)$(PREFIX)/include/libcqrlogo.h
+	$(LN) -sf libcqrlogo.so.$(SOVERSION) $(DESTDIR)$(PREFIX)/lib/libcqrlogo.so
+	$(INSTALL) -D -m0755 cqrlogo.cgi $(DESTDIR)$(PREFIX)/lib/cqrlogo/cqrlogo.cgi
+	$(INSTALL) -D -m0755 cqrlogo.fcgi $(DESTDIR)$(PREFIX)/lib/cqrlogo/cqrlogo.fcgi
 	$(INSTALL) -D -m0644 cqrlogo.conf $(DESTDIR)/etc/cqrlogo.conf
 
 install-config: config/apache.conf config/lighttpd.conf
 	$(INSTALL) -D -m0644 config/apache.conf $(DESTDIR)$(APACHECONF)/cqrlogo.conf
 	$(INSTALL) -D -m0644 config/lighttpd.conf $(DESTDIR)$(LIGHTTPDCONF)/cqrlogo.conf
 
-install-doc: README.html cqrlogo.png
+install-doc: README.md README.html cqrlogo.png
 	$(INSTALL) -D -m0644 README.md $(DESTDIR)$(PREFIX)/share/doc/cqrlogo/README.md
 	$(INSTALL) -D -m0644 README.html $(DESTDIR)$(PREFIX)/share/doc/cqrlogo/README.html
 	$(INSTALL) -D -m0644 cqrlogo.png $(DESTDIR)$(PREFIX)/share/doc/cqrlogo/cqrlogo.png
@@ -67,184 +75,184 @@ check:
 	$(RM) -f check.png
 
 	SERVER_NAME=$(SERVER) HTTP_REFERER=http://$(SERVER)/ \
-		    ./cqrlogo.cgi | $(SED) '1,/^$$/d' > check.png
+		$(CQRLOGO_CGI) | $(SED) '1,/^$$/d' > check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | $(GREP) -e '^http://$(SERVER)/$$'
 
 	SERVER_NAME=$(SERVER) HTTP_REFERER=https://$(SERVER)/ HTTPS=on \
-		    ./cqrlogo.cgi | $(SED) '1,/^$$/d' > check.png
+		$(CQRLOGO_CGI) | $(SED) '1,/^$$/d' > check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | $(GREP) -e '^https://$(SERVER)/$$'
 
 	SERVER_NAME=$(SERVER) HTTP_REFERER=http://$(SERVER)/ \
 		QUERY_STRING='scale=0' \
-		./cqrlogo.cgi | $(SED) '1,/^$$/d' > \
+		$(CQRLOGO_CGI) | $(SED) '1,/^$$/d' > \
 		check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | $(GREP) -e '^http://$(SERVER)/$$'
 
 	SERVER_NAME=$(SERVER) HTTP_REFERER=http://$(SERVER)/ \
 		QUERY_STRING='scale=4' \
-		./cqrlogo.cgi | $(SED) '1,/^$$/d' > \
+		$(CQRLOGO_CGI) | $(SED) '1,/^$$/d' > \
 		check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | $(GREP) -e '^http://$(SERVER)/$$'
 
 	SERVER_NAME=$(SERVER) HTTP_REFERER=http://$(SERVER)/ \
 		QUERY_STRING='scale=20' \
-		./cqrlogo.cgi | $(SED) '1,/^$$/d' > \
+		$(CQRLOGO_CGI) | $(SED) '1,/^$$/d' > \
 		check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | $(GREP) -e '^http://$(SERVER)/$$'
 
 	SERVER_NAME=$(SERVER) HTTP_REFERER=http://$(SERVER)/ \
 		QUERY_STRING='scale=2&border=0' \
-		./cqrlogo.cgi | $(SED) '1,/^$$/d' > \
+		$(CQRLOGO_CGI) | $(SED) '1,/^$$/d' > \
 		check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | $(GREP) -e '^http://$(SERVER)/$$'
 
 	SERVER_NAME=$(SERVER) HTTP_REFERER=http://$(SERVER)/ \
 		QUERY_STRING='scale=2&border=2' \
-		./cqrlogo.cgi | $(SED) '1,/^$$/d' > \
+		$(CQRLOGO_CGI) | $(SED) '1,/^$$/d' > \
 		check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | $(GREP) -e '^http://$(SERVER)/$$'
 
 	SERVER_NAME=$(SERVER) HTTP_REFERER=http://$(SERVER)/ \
 		QUERY_STRING='scale=2&border=10' \
-		./cqrlogo.cgi | $(SED) '1,/^$$/d' > \
+		$(CQRLOGO_CGI) | $(SED) '1,/^$$/d' > \
 		check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | $(GREP) -e '^http://$(SERVER)/$$'
 
 	SERVER_NAME=$(SERVER) HTTP_REFERER=http://$(SERVER)/ \
 		QUERY_STRING='scale=2&border=10&level=0' \
-		./cqrlogo.cgi | $(SED) '1,/^$$/d' > \
+		$(CQRLOGO_CGI) | $(SED) '1,/^$$/d' > \
 		check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | $(GREP) -e '^http://$(SERVER)/$$'
 
 	SERVER_NAME=$(SERVER) HTTP_REFERER=http://$(SERVER)/ \
 		QUERY_STRING='scale=2&border=10&level=2' \
-		./cqrlogo.cgi | $(SED) '1,/^$$/d' > \
+		$(CQRLOGO_CGI) | $(SED) '1,/^$$/d' > \
 		check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | $(GREP) -e '^http://$(SERVER)/$$'
 
 	SERVER_NAME=$(SERVER) HTTP_REFERER=http://$(SERVER)/ \
 		QUERY_STRING='scale=2&border=10&level=4' \
-		./cqrlogo.cgi | $(SED) '1,/^$$/d' > \
+		$(CQRLOGO_CGI) | $(SED) '1,/^$$/d' > \
 		check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | $(GREP) -e '^http://$(SERVER)/$$'
 
 	SERVER_NAME=eworm.net HTTP_REFERER=http://$(SERVER)/ \
-		./cqrlogo.cgi | $(SED) '1,/^$$/d' > \
+		$(CQRLOGO_CGI) | $(SED) '1,/^$$/d' > \
 		check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | \
 		$(GREP) -e '^This QR Code has been stolen from http://eworm.net/!$$'
 
 	SERVER_NAME=eworm.net HTTP_REFERER=https://$(SERVER)/ HTTPS=on \
-		./cqrlogo.cgi | $(SED) '1,/^$$/d' > \
+		$(CQRLOGO_CGI) | $(SED) '1,/^$$/d' > \
 		check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | \
 		$(GREP) -e '^This QR Code has been stolen from https://eworm.net/!$$'
 
 	SERVER_NAME=$(SERVER) HTTP_REFERER=http://$(SERVER)/ \
-		    ./cqrlogo.fcgi | $(SED) '1,/^$$/d' > check.png
+		$(CQRLOGO_FCGI) | $(SED) '1,/^$$/d' > check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | $(GREP) -e '^http://$(SERVER)/$$'
 
 	SERVER_NAME=$(SERVER) HTTP_REFERER=https://$(SERVER)/ HTTPS=on \
-		    ./cqrlogo.fcgi | $(SED) '1,/^$$/d' > check.png
+		$(CQRLOGO_FCGI) | $(SED) '1,/^$$/d' > check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | $(GREP) -e '^https://$(SERVER)/$$'
 
 	SERVER_NAME=$(SERVER) HTTP_REFERER=http://$(SERVER)/ \
 		QUERY_STRING='scale=0' \
-		./cqrlogo.fcgi | $(SED) '1,/^$$/d' > \
+		$(CQRLOGO_FCGI) | $(SED) '1,/^$$/d' > \
 		check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | $(GREP) -e '^http://$(SERVER)/$$'
 
 	SERVER_NAME=$(SERVER) HTTP_REFERER=http://$(SERVER)/ \
 		QUERY_STRING='scale=4' \
-		./cqrlogo.fcgi | $(SED) '1,/^$$/d' > \
+		$(CQRLOGO_FCGI) | $(SED) '1,/^$$/d' > \
 		check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | $(GREP) -e '^http://$(SERVER)/$$'
 
 	SERVER_NAME=$(SERVER) HTTP_REFERER=http://$(SERVER)/ \
 		QUERY_STRING='scale=20' \
-		./cqrlogo.fcgi | $(SED) '1,/^$$/d' > \
+		$(CQRLOGO_FCGI) | $(SED) '1,/^$$/d' > \
 		check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | $(GREP) -e '^http://$(SERVER)/$$'
 
 	SERVER_NAME=$(SERVER) HTTP_REFERER=http://$(SERVER)/ \
 		QUERY_STRING='scale=2&border=0' \
-		./cqrlogo.fcgi | $(SED) '1,/^$$/d' > \
+		$(CQRLOGO_FCGI) | $(SED) '1,/^$$/d' > \
 		check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | $(GREP) -e '^http://$(SERVER)/$$'
 
 	SERVER_NAME=$(SERVER) HTTP_REFERER=http://$(SERVER)/ \
 		QUERY_STRING='scale=2&border=2' \
-		./cqrlogo.fcgi | $(SED) '1,/^$$/d' > \
+		$(CQRLOGO_FCGI) | $(SED) '1,/^$$/d' > \
 		check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | $(GREP) -e '^http://$(SERVER)/$$'
 
 	SERVER_NAME=$(SERVER) HTTP_REFERER=http://$(SERVER)/ \
 		QUERY_STRING='scale=2&border=10' \
-		./cqrlogo.fcgi | $(SED) '1,/^$$/d' > \
+		$(CQRLOGO_FCGI) | $(SED) '1,/^$$/d' > \
 		check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | $(GREP) -e '^http://$(SERVER)/$$'
 
 	SERVER_NAME=$(SERVER) HTTP_REFERER=http://$(SERVER)/ \
 		QUERY_STRING='scale=2&border=10&level=0' \
-		./cqrlogo.fcgi | $(SED) '1,/^$$/d' > \
+		$(CQRLOGO_FCGI) | $(SED) '1,/^$$/d' > \
 		check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | $(GREP) -e '^http://$(SERVER)/$$'
 
 	SERVER_NAME=$(SERVER) HTTP_REFERER=http://$(SERVER)/ \
 		QUERY_STRING='scale=2&border=10&level=2' \
-		./cqrlogo.fcgi | $(SED) '1,/^$$/d' > \
+		$(CQRLOGO_FCGI) | $(SED) '1,/^$$/d' > \
 		check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | $(GREP) -e '^http://$(SERVER)/$$'
 
 	SERVER_NAME=$(SERVER) HTTP_REFERER=http://$(SERVER)/ \
 		QUERY_STRING='scale=2&border=10&level=4' \
-		./cqrlogo.fcgi | $(SED) '1,/^$$/d' > \
+		$(CQRLOGO_FCGI) | $(SED) '1,/^$$/d' > \
 		check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | $(GREP) -e '^http://$(SERVER)/$$'
 
 	SERVER_NAME=eworm.net HTTP_REFERER=http://$(SERVER)/ \
-		./cqrlogo.fcgi | $(SED) '1,/^$$/d' > \
+		$(CQRLOGO_FCGI) | $(SED) '1,/^$$/d' > \
 		check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | \
 		$(GREP) -e '^This QR Code has been stolen from http://eworm.net/!$$'
 
 	SERVER_NAME=eworm.net HTTP_REFERER=https://$(SERVER)/ HTTPS=on \
-		./cqrlogo.fcgi | $(SED) '1,/^$$/d' > \
+		$(CQRLOGO_FCGI) | $(SED) '1,/^$$/d' > \
 		check.png
 	$(FILE) check.png | $(GREP) 'PNG image data'
 	$(ZBARIMG) --raw -q check.png | \
 		$(GREP) -e '^This QR Code has been stolen from https://eworm.net/!$$'
 
 clean:
-	$(RM) -f *.o *~ *.png README.html cqrlogo.cgi cqrlogo.fcgi version.h
+	$(RM) -f *.o *~ *.png README.html lib/libcqrlogo.so lib/libcqrlogo.so.* cqrlogo.cgi cqrlogo.fcgi version.h
 
 distclean:
-	$(RM) -f *.o *~ *.png README.html cqrlogo.cgi cqrlogo.fcgi version.h config.h
+	$(RM) -f *.o *~ *.png README.html lib/libcqrlogo.so lib/libcqrlogo.so.* cqrlogo.cgi cqrlogo.fcgi version.h config.h
 
 release:
 	git archive --format=tar.xz --prefix=cqrlogo-$(VERSION)/ $(VERSION) > cqrlogo-$(VERSION).tar.xz
diff --git a/config.def.h b/config.def.h
index 1ac13c4..dc789d4 100644
--- a/config.def.h
+++ b/config.def.h
@@ -9,11 +9,11 @@
 #define _CONFIG_H
 
 /* path to the config file */
-#define CONFIGFILE	"/etc/cqrlogo.conf"
+#define CONFIGFILE		"/etc/cqrlogo.conf"
 
 /* whether or not defaults or settings from config may be overwritten
  * by query string */
-#define ALLOW_OVERWRITE	1
+#define ALLOW_OVERWRITE		1
 
 /* pixels are scaled up by this factor */
 #define QRCODE_SCALE		2
@@ -32,20 +32,10 @@
  *                  QR_ECLEVEL_Q (about 25%)
  *                  QR_ECLEVEL_H (highest, about 30%)
  * image size raises with higher levels */
-#define QRCODE_LEVEL	QR_ECLEVEL_L
+#define QRCODE_LEVEL		QR_ECLEVEL_L
 /* note that changing the level at runtime requies
  * a numeric value from 0 to 3 */
 
-/* if you really, really, really want to save some bytes...
- * It is possible to disable text information in PNG file completly, though
- * nobody will have an idea where you got this great software...
- * So please do not. */
-#define PNG_ENABLE_TEXT	1
-/* do you want version information within the PNG file? */
-#define PNG_ENABLE_TEXT_VERSIONS 1
-/* add referer information to the PNG file? */
-#define PNG_ENABLE_TEXT_REFERER 1
-
 #endif /* _CONFIG_H */
 
 // vim: set syntax=c:
diff --git a/cqrlogo.c b/cqrlogo.c
index 1681531..4b87371 100644
--- a/cqrlogo.c
+++ b/cqrlogo.c
@@ -5,285 +5,22 @@
  * of the GNU General Public License, incorporated herein by reference.
  */
 
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <inttypes.h>
-#include <regex.h>
-
-#include <iniparser.h>
-#include <png.h>
-#include <zlib.h>
-#include <qrencode.h>
-
-#if HAVE_FCGI
-#include <fcgi_stdio.h>
-#endif
-
 #include "config.h"
 #include "version.h"
 
-/* define structs and functions */
 #include "cqrlogo.h"
 
-#define URLPATTERN "^[hH][tT][tT][pP][sS]\\?://%s/"
-#define TEXTSTOLEN "This QR Code has been stolen from http%s://%s/!"
-
-#if defined PNG_TEXT_SUPPORTED && PNG_ENABLE_TEXT
-/*** add_png_text ***/
-png_text * add_png_text(png_text *pngtext, unsigned int *textcount, char *key, char *text) {
-	pngtext = realloc(pngtext, ((*textcount) + 1) * sizeof(png_text));
-
-	pngtext[*textcount].compression = PNG_TEXT_COMPRESSION_zTXt;
-	pngtext[*textcount].key = key;
-	pngtext[*textcount].text = text;
-
-	(*textcount)++;
-	return pngtext;
-}
-#endif
-
-#if HAVE_FCGI
-/*** png_write_stdout ***/
-void png_write_stdout(png_structp png_ptr, png_bytep data, png_size_t length) {
-	if (length != fwrite(data, 1, length, png_get_io_ptr(png_ptr)))
-		png_error(png_ptr, "Write Error");
-}
-
-/*** png_flush_stdout ***/
-void png_flush_stdout(png_structp png_ptr) {
-	fflush(stdout);
-}
-#endif
-
-/*** generate_png ***/
-int generate_png (struct bitmap_t *bitmap, const char *uri) {
-	png_structp png_ptr = NULL;
-	png_infop info_ptr = NULL;
-	png_byte ** row_pointers = NULL;
-	unsigned int x, y;
-	uint8_t bit, byte;
-
-	if ((png_ptr = png_create_write_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL)) == NULL)
-		return 1;
-
-	if ((info_ptr = png_create_info_struct (png_ptr)) == NULL ||
-			(setjmp (png_jmpbuf (png_ptr)))) {
-		png_destroy_write_struct (&png_ptr, &info_ptr);
-		return 1;
-	}
-
-	png_set_IHDR (png_ptr, info_ptr, bitmap->width, bitmap->height, 1 /* depth */,
-		PNG_COLOR_TYPE_GRAY, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
-
-	/* use best compression */
-	png_set_compression_level(png_ptr, Z_BEST_COMPRESSION);
-
-	/* use compression strategy filtered
-	 * this way pngcrush can not optimize any more */
-	png_set_compression_strategy(png_ptr, Z_FILTERED);
-
-#if defined PNG_TEXT_SUPPORTED && PNG_ENABLE_TEXT
-	unsigned int textcount = 0;
-	png_text *pngtext = NULL;
-
-	pngtext = add_png_text(pngtext, &textcount, "comment", "QR-Code created by cqrlogo - https://github.com/eworm-de/cqrlogo");
-#	if PNG_ENABLE_TEXT_REFERER
-	pngtext = add_png_text(pngtext, &textcount, "referer", (char *)uri);
-#	endif
-
-#	if PNG_ENABLE_TEXT_VERSIONS
-#if HAVE_FCGI
-#	define VERSIONSTR	VERSION " (FastCGI) (" __DATE__ ", " __TIME__ ")"
-#else
-#	define VERSIONSTR	VERSION " (CGI) (" __DATE__ ", " __TIME__ ")"
-#endif
-#	define LIBSSTR		"libqrencode %s, libpng %s, zlib %s"
-	char *libsstr, *qrver = QRcode_APIVersionString();
-
-	libsstr = malloc(sizeof(LIBSSTR) + strlen(qrver) + strlen(png_libpng_ver) + strlen(zlib_version));
-	sprintf(libsstr, LIBSSTR, qrver, png_libpng_ver, zlib_version);
-
-	pngtext = add_png_text(pngtext, &textcount, "version", VERSIONSTR);
-	pngtext = add_png_text(pngtext, &textcount, "libs", libsstr);
-#	endif
-
-	png_set_text(png_ptr, info_ptr, pngtext, textcount);
-	png_free (png_ptr, pngtext);
-#	if PNG_ENABLE_TEXT_VERSIONS
-	free(libsstr);
-#	endif
-#endif
-
-	row_pointers = png_malloc (png_ptr, bitmap->height * sizeof (png_byte *));
-	for (y = 0; y < bitmap->height; ++y) {
-		/* we need to round up, need a complete byte for less than eight bits */
-		row_pointers[y] = png_malloc (png_ptr, (sizeof(uint8_t) * bitmap->width + 7) / 8);
-		for (x = 0; x < bitmap->width; ++x) {
-			/* bit are written in reverse order! */
-			bit = 7 - (x % 8);
-			byte = x / 8;
-			if (bitmap->pixel[y * bitmap->width + x])
-				row_pointers[y][byte] |= 1 << (bit);
-			else
-				row_pointers[y][byte] &= ~(1 << (bit));
-		}
-	}
-
-#if HAVE_FCGI
-	/* with fastcgi we can not just open stdout for writing...
-	 * define a write function instead */
-	png_set_write_fn(png_ptr, (png_voidp)stdout, png_write_stdout, png_flush_stdout);
-#else
-	png_init_io (png_ptr, stdout);
-#endif
-
-	png_set_rows (png_ptr, info_ptr, row_pointers);
-	png_write_png (png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, NULL);
-
-	for (y = 0; y < bitmap->height; ++y)
-		png_free (png_ptr, row_pointers[y]);
-	png_free (png_ptr, row_pointers);
-	png_destroy_write_struct(&png_ptr, &info_ptr);
-
-	return 0;
-}
-
-/*** bitmap_new ***/
-struct bitmap_t * bitmap_new(int width, int height) {
-	struct bitmap_t *bitmap;
-
-	if ((bitmap = malloc(sizeof(struct bitmap_t))) == NULL)
-		return NULL;
-
-	bitmap->width = width;
-	bitmap->height = height;
-	if ((bitmap->pixel = malloc(width * height * sizeof(uint8_t))) == NULL) {
-		free(bitmap);
-		return NULL;
-	}
-
-	/* initialize with white */
-	memset(bitmap->pixel, 0xff, width * height);
-
-	return bitmap;
-}
-
-/*** bitmap_free ***/
-void bitmap_free(struct bitmap_t * bitmap) {
-	free(bitmap->pixel);
-	free(bitmap);
-}
-
-/*** encode_qrcode ***/
-struct bitmap_t * encode_qrcode (const char *text, unsigned int scale,
-		unsigned int border, unsigned int level) {
-	QRcode *qrcode;
-	struct bitmap_t *bitmap, *scaled;
-	int i, j, k, l;
-	unsigned char *data;
-
-	qrcode = QRcode_encodeString8bit(text, 0, level);
-
-	/* this happens if the string is too long
-	 * possibly we have an URL (referer) that is too long, so the code
-	 * automatically falls back to http_server (see main()) */
-	if (qrcode == NULL)
-		return NULL;
-
-	data = qrcode->data;
-
-	/* wirte QR code to bitmap */
-	if ((bitmap = bitmap_new(qrcode->width + border * 2, qrcode->width + border * 2)) == NULL)
-		return NULL;
-	for (i = border; i < qrcode->width + border; i++)
-		for (j = border; j < qrcode->width + border; j++) {
-			bitmap->pixel[i * (qrcode->width + border * 2) + j] = !(*data & 0x1) * 0xff;
-			data++;
-		}
-
-	QRcode_free(qrcode);
-
-	if (scale == 1)
-		return bitmap;
-
-	/* scale bitmap */
-	if ((scaled = bitmap_new(bitmap->width * scale, bitmap->height * scale)) == NULL)
-		return NULL;
-	for (i = 0; i < bitmap->height; i++)
-		for (j = 0; j < bitmap->width; j++)
-			for (k = 0; k < scale; k++)
-				for (l = 0; l < scale; l++)
-					scaled->pixel[i * bitmap->width * scale * scale + k * bitmap->width * scale + j * scale + l] =
-						bitmap->pixel[i * bitmap->width + j];
-
-
-	bitmap_free(bitmap);
-
-	return scaled;
-}
-
-/*** get_query_value ***/
-unsigned int get_query_value(const char *query_string, const char *pattern,
-		unsigned int value, unsigned int min, unsigned int max) {
-	char *match = NULL, *newpattern = NULL;
-	unsigned int length;
-	int tmp = -1;
-
-	newpattern = strdup(pattern);
-
-	length = strlen(newpattern);
-	/* length is without null termination, allocacte 4 bytes so we
-	 * have "=", "%u" and null termination */
-	newpattern = realloc(newpattern, length + 4);
-	sprintf(newpattern + length, "=");
-
-	if ((match = strstr(query_string, newpattern)) != NULL) {
-		sprintf(newpattern + length + 1, "%%u");
-
-		if ((sscanf(match, newpattern, &tmp)) > 0)
-			if (tmp >= min && tmp <= max)
-				value = tmp;
-	}
-
-	free(newpattern);
-
-	return value;
-}
-
-/*** get_ini_value ***/
-unsigned int get_ini_value(dictionary * ini, uint8_t type, const char * section, const char * parameter,
-		unsigned int value, unsigned int min, unsigned int max) {
-	char * key;
-	unsigned int tmp;
-
-	key = malloc(strlen(section) + strlen(parameter) + 2);
-	sprintf(key, "%s:%s", section, parameter);
-
-	if (type)
-		tmp = iniparser_getint(ini, key, value);
-	else
-		tmp = iniparser_getboolean(ini, key, value);
-
-	if (tmp >= min && tmp <= max)
-		value = tmp;
-
-	free(key);
-
-	return value;
-}
-
 /*** main ***/
 int main(int argc, char **argv) {
-	dictionary * ini;
 	const char * http_referer, * server_name, * query_string, * uri;
 	char * uri_server_name, * uri_png, * pattern, * stolen;
 	regex_t preg;
 	regmatch_t pmatch[1];
-	uint8_t https, overwrite;
+	uint8_t https;
 
+	struct png_t * png;
 	struct bitmap_t * bitmap;
-	unsigned int scale, border, level;
+	struct cqrconf_t cqrconf;
 
 #if HAVE_FCGI
 	/* loop for requests */
@@ -296,11 +33,12 @@ int main(int argc, char **argv) {
 	stolen = NULL;
 
 	https = 0;
-	overwrite = ALLOW_OVERWRITE;
 
-	scale = QRCODE_SCALE;
-	border = QRCODE_BORDER;
-	level = QRCODE_LEVEL;
+	/* these default values are defined in config.h */
+	cqrconf.scale = QRCODE_SCALE;
+	cqrconf.border = QRCODE_BORDER;
+	cqrconf.level = QRCODE_LEVEL;
+	cqrconf.overwrite = ALLOW_OVERWRITE;
 
 	/* check if we have environment variables from CGI */
 	if ((server_name = getenv("SERVER_NAME")) == NULL) {
@@ -344,42 +82,14 @@ int main(int argc, char **argv) {
 		uri = uri_server_name;
 	}
 
-	/* parse config file */
-	if ((ini = iniparser_load(CONFIGFILE)) == NULL) {
-		fprintf(stderr, "cannot parse file " CONFIGFILE ", continue anyway\n");
-	/* continue anyway, there is nothing essential in the config file */
-	} else {
-		scale = get_ini_value(ini, 1, "general", "scale", scale, 1, QRCODE_MAX_SCALE);
-		border = get_ini_value(ini, 1, "general", "border", border, 0, QRCODE_MAX_BORDER);
-		level = get_ini_value(ini, 1, "general", "level", level, QR_ECLEVEL_L, QR_ECLEVEL_H);
-		overwrite = get_ini_value(ini, 0, "general", "allow overwrite", overwrite, 0, 1);
-
-		scale = get_ini_value(ini, 1, server_name, "scale", scale, 1, QRCODE_MAX_SCALE);
-		border = get_ini_value(ini, 1, server_name, "border", border, 0, QRCODE_MAX_BORDER);
-		level = get_ini_value(ini, 1, server_name, "level", level, QR_ECLEVEL_L, QR_ECLEVEL_H);
-		overwrite = get_ini_value(ini, 0, server_name, "allow overwrite", overwrite, 0, 1);
-
-		/* done reading config file, free */
-		iniparser_freedict(ini);
-	}
-
-	/* get query string and read settings */
-	if (overwrite && (query_string = getenv("QUERY_STRING")) != NULL) {
-		/* do we have a special scale? */
-		scale = get_query_value(query_string, "scale", scale, 1, QRCODE_MAX_SCALE);
-
-		/* width of the border? */
-		border = get_query_value(query_string, "border", border, 0, QRCODE_MAX_BORDER);
-
-		/* error correction level? */
-		level = get_query_value(query_string, "level", level, QR_ECLEVEL_L, QR_ECLEVEL_H);
-	}
+	cqrconf_file(server_name, &cqrconf);
+	cqrconf_string(getenv("QUERY_STRING"), &cqrconf);
 
 	/* encode the QR-Code */
-	if ((bitmap = encode_qrcode(uri, scale, border, level)) == NULL) {
+	if ((bitmap = encode_qrcode(uri, cqrconf)) == NULL) {
 		/* uri too long? retry with uri from server name */
 		uri = uri_server_name;
-		if ((bitmap = encode_qrcode(uri, scale, border, level)) == NULL) {
+		if ((bitmap = encode_qrcode(uri, cqrconf)) == NULL) {
 			fprintf(stderr, "Could not generate QR-Code.\n");
 			return EXIT_FAILURE;
 		}
@@ -395,12 +105,15 @@ int main(int argc, char **argv) {
 		uri = uri_png;
 	}
 
-	/* print PNG data */
-	if (generate_png(bitmap, uri)) {
+	/* generate PNG data */
+	if ((png = generate_png(bitmap, CQR_COMMENT|CQR_REFERER|CQR_VERSION|CQR_LIBVERSION, uri)) == NULL) {
 		fprintf(stderr, "Failed to generate PNG.\n");
 		return EXIT_FAILURE;
 	}
 
+	/* write PNG data to stdout */
+	fwrite(png->buffer, png->size, 1, stdout);
+
 	/* free memory we no longer need */
 	if (uri_server_name)
 		free(uri_server_name);
@@ -409,6 +122,9 @@ int main(int argc, char **argv) {
 	if (uri_png)
 		free(uri_png);
 	bitmap_free(bitmap);
+	if (png->size > 0)
+		free(png->buffer);
+	free(png);
 
 #if HAVE_FCGI
 	/* end of loop */
diff --git a/cqrlogo.h b/cqrlogo.h
index d14050d..00795b9 100644
--- a/cqrlogo.h
+++ b/cqrlogo.h
@@ -8,45 +8,24 @@
 #ifndef _CQRLOGO_H
 #define _CQRLOGO_H
 
-/* a bitmap */
-struct bitmap_t {
-	unsigned int width;
-	unsigned int height;
-	uint8_t *pixel;
-};
-
-#if defined PNG_TEXT_SUPPORTED && PNG_ENABLE_TEXT
-/*** add_png_text ***/
-png_text * add_png_text(png_text *pngtext, unsigned int *textcount, char *key, char *text);
-#endif
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <inttypes.h>
+#include <regex.h>
+#include <stdbool.h>
 
 #if HAVE_FCGI
-/*** png_write_stdout ***/
-void png_write_stdout(png_structp png_ptr, png_bytep data, png_size_t length);
-
-/*** png_flush_stdout ***/
-void png_flush_stdout(png_structp png_ptr);
+#include <fcgi_stdio.h>
 #endif
 
-/*** generate_png ***/
-int generate_png (struct bitmap_t *bitmap, const char *uri);
-
-/*** bitmap_new ***/
-struct bitmap_t * bitmap_new(int width, int height);
-/*** bitmap_free ***/
-void bitmap_free(struct bitmap_t * bitmap);
-
-/*** encode_qrcode ***/
-struct bitmap_t * encode_qrcode (const char *text, unsigned int scale,
-		unsigned int border, unsigned int level);
+#include <libcqrlogo.h>
 
-/*** get_query_value ***/
-unsigned int get_query_value(const char *query_string, const char *pattern,
-		unsigned int value, unsigned int min, unsigned int max);
+#define URLPATTERN "^[hH][tT][tT][pP][sS]\\?://%s/"
+#define TEXTSTOLEN "This QR Code has been stolen from http%s://%s/!"
 
-/*** get_ini_value ***/
-unsigned int get_ini_value(dictionary * ini, uint8_t type, const char * section, const char * parameter,
-		unsigned int value, unsigned int min, unsigned int max);
+/*** main ***/
+int main(int argc, char **argv);
 
 #endif /* _CQRLOGO_H */
 
diff --git a/lib/.gitignore b/lib/.gitignore
new file mode 100644
index 0000000..6842a0a
--- /dev/null
+++ b/lib/.gitignore
@@ -0,0 +1,2 @@
+libcqrlogo.so
+libcqrlogo.so.*
diff --git a/lib/Makefile b/lib/Makefile
new file mode 100644
index 0000000..47f4db7
--- /dev/null
+++ b/lib/Makefile
@@ -0,0 +1,21 @@
+# cqrlogo - CGI QR-Code logo for web services
+
+CC	:= gcc
+LN	:= ln
+CFLAGS	+= -O2 -Wall -Werror
+CFLAGS	+= -liniparser
+CFLAGS	+= $(shell pkg-config --cflags --libs libpng)
+CFLAGS	+= $(shell pkg-config --cflags --libs zlib)
+CFLAGS	+= $(shell pkg-config --cflags --libs libqrencode)
+
+# library abi version
+SOVERSION	:= 0
+
+all: libcqrlogo
+
+libcqrlogo: libcqrlogo.c libcqrlogo.h ../config.h ../version.h
+	$(CC) $(CFLAGS) $(LDFLAGS) -shared -fPIC -Wl,-soname,libcqrlogo.so.$(SOVERSION) -o libcqrlogo.so.$(SOVERSION) libcqrlogo.c
+	$(LN) -sf libcqrlogo.so.$(SOVERSION) libcqrlogo.so
+
+clean:
+	$(RM) -f *.o *~ libcqrlogo.so libcqrlogo.so.*
diff --git a/lib/libcqrlogo.c b/lib/libcqrlogo.c
new file mode 100644
index 0000000..aca5cb5
--- /dev/null
+++ b/lib/libcqrlogo.c
@@ -0,0 +1,295 @@
+/*
+ * (C) 2013-2014 by Christian Hesse <mail@eworm.de>
+ *
+ * This software may be used and distributed according to the terms
+ * of the GNU General Public License, incorporated herein by reference.
+ */
+
+#include "../config.h"
+#include "../version.h"
+
+/* define structs and functions */
+#include "libcqrlogo.h"
+
+/*** png_write_stdout ***/
+void png_write_fn(png_structp png_ptr, png_bytep data, png_size_t length) {
+	struct png_t * png;
+
+	png = (struct png_t *)png_get_io_ptr(png_ptr);
+
+	png->buffer = realloc(png->buffer, png->size + length);
+
+  	memcpy(png->buffer + png->size, data, length);
+
+	png->size += length;
+}
+
+#if defined PNG_TEXT_SUPPORTED
+/*** add_png_text ***/
+png_text * add_png_text(png_text *pngtext, unsigned int *textcount, char *key, char *text) {
+	pngtext = realloc(pngtext, ((*textcount) + 1) * sizeof(png_text));
+
+	pngtext[*textcount].compression = PNG_TEXT_COMPRESSION_zTXt;
+	pngtext[*textcount].key = key;
+	pngtext[*textcount].text = text;
+
+	(*textcount)++;
+	return pngtext;
+}
+#endif
+
+/*** generate_png ***/
+struct png_t * generate_png (struct bitmap_t *bitmap, const uint8_t meta, const char *uri) {
+	png_structp png_ptr = NULL;
+	png_infop info_ptr = NULL;
+	png_byte ** row_pointers = NULL;
+	unsigned int x, y;
+	uint8_t bit, byte;
+	struct png_t * png;
+
+	png = malloc(sizeof(struct png_t));
+	png->buffer = NULL;
+	png->size = 0;
+
+	if ((png_ptr = png_create_write_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL)) == NULL)
+		return NULL;
+
+	if ((info_ptr = png_create_info_struct (png_ptr)) == NULL ||
+			(setjmp (png_jmpbuf (png_ptr)))) {
+		png_destroy_write_struct (&png_ptr, &info_ptr);
+		return NULL;
+	}
+
+	png_set_IHDR (png_ptr, info_ptr, bitmap->width, bitmap->height, 1 /* depth */,
+		PNG_COLOR_TYPE_GRAY, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
+
+	/* use best compression */
+	png_set_compression_level(png_ptr, Z_BEST_COMPRESSION);
+
+	/* use compression strategy filtered
+	 * this way pngcrush can not optimize any more */
+	png_set_compression_strategy(png_ptr, Z_FILTERED);
+
+#if defined PNG_TEXT_SUPPORTED
+	unsigned int textcount = 0;
+	png_text *pngtext = NULL;
+	char *libsstr = NULL, *qrver;
+
+	if (meta & CQR_COMMENT)
+		pngtext = add_png_text(pngtext, &textcount, "comment", "QR-Code created by cqrlogo - https://github.com/eworm-de/cqrlogo");
+
+	if (meta & CQR_REFERER)
+		pngtext = add_png_text(pngtext, &textcount, "referer", (char *)uri);
+
+	if (meta & CQR_VERSION)
+		pngtext = add_png_text(pngtext, &textcount, "version", VERSIONSTR);
+
+	if (meta & CQR_LIBVERSION) {
+		qrver = QRcode_APIVersionString();
+
+		libsstr = malloc(sizeof(LIBSSTR) + strlen(qrver) + strlen(png_libpng_ver) + strlen(zlib_version));
+		sprintf(libsstr, LIBSSTR, qrver, png_libpng_ver, zlib_version);
+
+		pngtext = add_png_text(pngtext, &textcount, "libs", libsstr);
+	}
+
+	png_set_text(png_ptr, info_ptr, pngtext, textcount);
+	png_free (png_ptr, pngtext);
+	if (libsstr)
+		free(libsstr);
+#endif
+
+	row_pointers = png_malloc (png_ptr, bitmap->height * sizeof (png_byte *));
+	for (y = 0; y < bitmap->height; ++y) {
+		/* we need to round up, need a complete byte for less than eight bits */
+		row_pointers[y] = png_malloc (png_ptr, (sizeof(uint8_t) * bitmap->width + 7) / 8);
+		for (x = 0; x < bitmap->width; ++x) {
+			/* bit are written in reverse order! */
+			bit = 7 - (x % 8);
+			byte = x / 8;
+			if (bitmap->pixel[y * bitmap->width + x])
+				row_pointers[y][byte] |= 1 << (bit);
+			else
+				row_pointers[y][byte] &= ~(1 << (bit));
+		}
+	}
+
+	/* with FastCGI we can not just open stdout for writing...
+	 * define a write function instead */
+	png_set_write_fn(png_ptr, png, png_write_fn, NULL);
+
+	png_set_rows (png_ptr, info_ptr, row_pointers);
+	png_write_png (png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, NULL);
+
+	for (y = 0; y < bitmap->height; ++y)
+		png_free (png_ptr, row_pointers[y]);
+	png_free (png_ptr, row_pointers);
+	png_destroy_write_struct(&png_ptr, &info_ptr);
+
+	return png;
+}
+
+/*** bitmap_new ***/
+struct bitmap_t * bitmap_new(int width, int height) {
+	struct bitmap_t *bitmap;
+
+	if ((bitmap = malloc(sizeof(struct bitmap_t))) == NULL)
+		return NULL;
+
+	bitmap->width = width;
+	bitmap->height = height;
+	if ((bitmap->pixel = malloc(width * height * sizeof(uint8_t))) == NULL) {
+		free(bitmap);
+		return NULL;
+	}
+
+	/* initialize with white */
+	memset(bitmap->pixel, 0xff, width * height);
+
+	return bitmap;
+}
+
+/*** bitmap_free ***/
+void bitmap_free(struct bitmap_t * bitmap) {
+	free(bitmap->pixel);
+	free(bitmap);
+}
+
+/*** encode_qrcode ***/
+struct bitmap_t * encode_qrcode (const char *text, const struct cqrconf_t cqrconf) {
+	QRcode *qrcode;
+	struct bitmap_t *bitmap, *scaled;
+	int i, j, k, l;
+	unsigned char *data;
+
+	qrcode = QRcode_encodeString8bit(text, 0, cqrconf.level);
+
+	/* this happens if the string is too long
+	 * possibly we have an URL (referer) that is too long, so the code
+	 * automatically falls back to http_server (see main()) */
+	if (qrcode == NULL)
+		return NULL;
+
+	data = qrcode->data;
+
+	/* wirte QR code to bitmap */
+	if ((bitmap = bitmap_new(qrcode->width + cqrconf.border * 2, qrcode->width + cqrconf.border * 2)) == NULL)
+		return NULL;
+	for (i = cqrconf.border; i < qrcode->width + cqrconf.border; i++)
+		for (j = cqrconf.border; j < qrcode->width + cqrconf.border; j++) {
+			bitmap->pixel[i * (qrcode->width + cqrconf.border * 2) + j] = !(*data & 0x1) * 0xff;
+			data++;
+		}
+
+	QRcode_free(qrcode);
+
+	if (cqrconf.scale == 1)
+		return bitmap;
+
+	/* cqrconf.scale bitmap */
+	if ((scaled = bitmap_new(bitmap->width * cqrconf.scale, bitmap->height * cqrconf.scale)) == NULL)
+		return NULL;
+	for (i = 0; i < bitmap->height; i++)
+		for (j = 0; j < bitmap->width; j++)
+			for (k = 0; k < cqrconf.scale; k++)
+				for (l = 0; l < cqrconf.scale; l++)
+					scaled->pixel[i * bitmap->width * cqrconf.scale * cqrconf.scale + k * bitmap->width * cqrconf.scale + j * cqrconf.scale + l] =
+						bitmap->pixel[i * bitmap->width + j];
+
+
+	bitmap_free(bitmap);
+
+	return scaled;
+}
+
+/*** get_query_value ***/
+unsigned int get_query_value(const char *query_string, const char *pattern,
+		unsigned int value, unsigned int min, unsigned int max) {
+	char *match = NULL, *newpattern = NULL;
+	unsigned int length;
+	int tmp = -1;
+
+	newpattern = strdup(pattern);
+
+	length = strlen(newpattern);
+	/* length is without null termination, allocacte 4 bytes so we
+	 * have "=", "%u" and null termination */
+	newpattern = realloc(newpattern, length + 4);
+	sprintf(newpattern + length, "=");
+
+	if ((match = strstr(query_string, newpattern)) != NULL) {
+		sprintf(newpattern + length + 1, "%%u");
+
+		if ((sscanf(match, newpattern, &tmp)) > 0)
+			if (tmp >= min && tmp <= max)
+				value = tmp;
+	}
+
+	free(newpattern);
+
+	return value;
+}
+
+/*** get_ini_value ***/
+unsigned int get_ini_value(dictionary * ini, uint8_t type, const char * section, const char * parameter,
+		unsigned int value, unsigned int min, unsigned int max) {
+	char * key;
+	unsigned int tmp;
+
+	key = malloc(strlen(section) + strlen(parameter) + 2);
+	sprintf(key, "%s:%s", section, parameter);
+
+	if (type)
+		tmp = iniparser_getint(ini, key, value);
+	else
+		tmp = iniparser_getboolean(ini, key, value);
+
+	if (tmp >= min && tmp <= max)
+		value = tmp;
+
+	free(key);
+
+	return value;
+}
+
+/*** cqrconf_file ***/
+void cqrconf_file(const char * server_name, struct cqrconf_t * cqrconf) {
+	dictionary * ini;
+
+	/* parse config file */
+	if ((ini = iniparser_load(CONFIGFILE)) == NULL) {
+		fprintf(stderr, "cannot parse file " CONFIGFILE ", continue anyway\n");
+		return;
+	}
+
+	cqrconf->scale = get_ini_value(ini, 1, "general", "scale", cqrconf->scale, 1, QRCODE_MAX_SCALE);
+	cqrconf->border = get_ini_value(ini, 1, "general", "border", cqrconf->border, 0, QRCODE_MAX_BORDER);
+	cqrconf->level = get_ini_value(ini, 1, "general", "level", cqrconf->level, QR_ECLEVEL_L, QR_ECLEVEL_H);
+	cqrconf->overwrite = get_ini_value(ini, 0, "general", "allow overwrite", cqrconf->overwrite, false, true);
+
+	cqrconf->scale = get_ini_value(ini, 1, server_name, "scale", cqrconf->scale, 1, QRCODE_MAX_SCALE);
+	cqrconf->border = get_ini_value(ini, 1, server_name, "border", cqrconf->border, 0, QRCODE_MAX_BORDER);
+	cqrconf->level = get_ini_value(ini, 1, server_name, "level", cqrconf->level, QR_ECLEVEL_L, QR_ECLEVEL_H);
+	cqrconf->overwrite = get_ini_value(ini, 0, server_name, "allow overwrite", cqrconf->overwrite, false, true);
+
+	/* done reading config file, free */
+	iniparser_freedict(ini);
+}
+
+/*** cqrconf_string ***/
+void cqrconf_string(const char * query_string, struct cqrconf_t * cqrconf) {
+	if (cqrconf->overwrite == false)
+		return;
+
+	if (query_string == NULL)
+		return;
+
+	/* do we have a special scale? */
+	cqrconf->scale = get_query_value(query_string, "scale", cqrconf->scale, 1, QRCODE_MAX_SCALE);
+
+	/* width of the border? */
+	cqrconf->border = get_query_value(query_string, "border", cqrconf->border, 0, QRCODE_MAX_BORDER);
+
+	/* error correction level? */
+	cqrconf->level = get_query_value(query_string, "level", cqrconf->level, QR_ECLEVEL_L, QR_ECLEVEL_H);
+}
diff --git a/lib/libcqrlogo.h b/lib/libcqrlogo.h
new file mode 100644
index 0000000..8ce04f2
--- /dev/null
+++ b/lib/libcqrlogo.h
@@ -0,0 +1,84 @@
+/*
+ * (C) 2013-2014 by Christian Hesse <mail@eworm.de>
+ *
+ * This software may be used and distributed according to the terms
+ * of the GNU General Public License, incorporated herein by reference.
+ */
+
+#ifndef _LIBCQRLOGO_H
+#define _LIBCQRLOGO_H
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <inttypes.h>
+#include <stdbool.h>
+
+#include <png.h>
+#include <zlib.h>
+#include <qrencode.h>
+#include <iniparser.h>
+
+/* a bitmap */
+struct bitmap_t {
+	unsigned int width;
+	unsigned int height;
+	uint8_t *pixel;
+};
+
+/* finished PNG image */
+struct png_t {
+	unsigned char * buffer;
+	size_t size;
+};
+
+/* config */
+struct cqrconf_t {
+	uint8_t scale;
+	uint8_t border;
+	uint8_t level;
+	bool overwrite;
+};
+
+#define CQR_COMMENT	0x1
+#define CQR_REFERER	0x2
+#define CQR_VERSION	0x4
+#define CQR_LIBVERSION	0x8
+
+#define VERSIONSTR	VERSION " (" __DATE__ ", " __TIME__ ")"
+#define LIBSSTR		"libqrencode %s, libpng %s, zlib %s"
+
+/*** png_write_stdout ***/
+void png_write_fn(png_structp png_ptr, png_bytep data, png_size_t length);
+
+#if defined PNG_TEXT_SUPPORTED
+/*** add_png_text ***/
+png_text * add_png_text(png_text *pngtext, unsigned int *textcount, char *key, char *text);
+#endif
+
+/*** generate_png ***/
+struct png_t * generate_png (struct bitmap_t *bitmap, const uint8_t meta, const char *uri);
+
+/*** bitmap_new ***/
+struct bitmap_t * bitmap_new(int width, int height);
+/*** bitmap_free ***/
+void bitmap_free(struct bitmap_t * bitmap);
+
+/*** encode_qrcode ***/
+struct bitmap_t * encode_qrcode (const char *text, const struct cqrconf_t);
+
+/*** get_query_value ***/
+unsigned int get_query_value(const char *query_string, const char *pattern,
+	unsigned int value, unsigned int min, unsigned int max);
+/*** get_ini_value ***/
+unsigned int get_ini_value(dictionary * ini, uint8_t type, const char * section, const char * parameter,
+	unsigned int value, unsigned int min, unsigned int max);
+
+/*** cqrconf_file ***/
+void cqrconf_file(const char * server_name, struct cqrconf_t * cqrconf);
+/*** cqrconf_string ***/
+void cqrconf_string(const char * query_string, struct cqrconf_t * cqrconf);
+
+#endif /* _LIBCQRLOGO_H */
+
+// vim: set syntax=c: