use the builtin config also as a default one

This depends on fopencookie, which is linux-specific. For BSD, there is
a similar function called funopen, which can be used as a drop-in
replacement.

configure.ac.in

@@ -101,6 +101,7 @@ AC_ARG_ENABLE([config_output],
 AM_CONDITIONAL(BUILD_CONFIG_OUTPUT, test x$want_config_output = xyes)
 if test x$want_config_output = xyes; then
   AC_DEFINE(CONFIG_OUTPUT, 1, [Define if you want conky to output a default config (with -C)])
+  AC_CHECK_FUNCS(fopencookie, AM_CONDITIONAL(BUILD_FOR_FOPENCOOKIE, true))
 fi
 
 dnl

src/Makefile.am

@@ -29,6 +29,9 @@ bin_PROGRAMS = conky
 
 if BUILD_CONFIG_OUTPUT
 config_output = defconfig.h
+if BUILD_FOR_FOPENCOOKIE
+config_cookie = conf_cookie.c conf_cookie.h
+endif
 conky_DEPENDENCIES = $(config_output)
 BUILT_SOURCES = $(config_output)
 CLEANFILES = $(config_output)
@@ -110,6 +113,7 @@ endif
 
 conky_SOURCES = 		\
 	$(config_output)        \
+	$(config_cookie)        \
 	$(audacious)            \
 	$(bmpx)                 \
 	common.c 		\
@@ -146,6 +150,7 @@ conky_LDFLAGS = 				\
 
 EXTRA_DIST = 			\
 	$(config_output)        \
+	$(config_cookie)        \
 	audacious.c		\
 	audacious.h		\
 	bmpx.c			\

src/conf_cookie.c

@@ -0,0 +1,33 @@
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <sys/types.h>
+#include "defconfig.h"
+
+ssize_t conf_read(void *cookie, char *buf, size_t size)
+{
+	static int col = 0, row = 0;
+	size_t i = 0;
+	const char *conf[] = defconfig;
+
+	(void)cookie;
+
+	while (i < size) {
+		if (!(conf[row]))		/* end of rows */
+			break;
+		if (!(conf[row][col])) {	/* end of line */
+			row++;
+			col = 0;
+			continue;
+		}
+		buf[i++] = conf[row][col++];
+	}
+	return i;
+}
+
+cookie_io_functions_t conf_cookie = {
+	.read = &conf_read,
+	.write = NULL,
+	.seek = NULL,
+	.close = NULL,
+};
+

src/conf_cookie.h

@@ -0,0 +1,8 @@
+#ifndef _CONF_COOKIE_H
+#define _CONF_COOKIE_H
+
+#include <stdio.h>
+
+extern cookie_io_functions_t conf_cookie;
+
+#endif /* _CONF_COOKIE_H */

src/conky.c

@@ -60,6 +60,9 @@
 
 #ifdef CONFIG_OUTPUT
 #include "defconfig.h"
+#ifdef HAVE_FOPENCOOKIE
+#include "conf_cookie.h"
+#endif
 #endif
 
 #include "build.h"
@@ -7761,10 +7764,19 @@ static void load_config_file(const char *f)
 	FILE *fp;
 
 	set_default_configurations();
-	fp = fopen(f, "r");
+#ifdef CONFIG_OUTPUT
+	if (!strcmp(f, "==builtin==")) {
+#ifdef HAVE_FOPENCOOKIE
+		fp = fopencookie(NULL, "r", conf_cookie);
+#endif
+	} else
+#endif /* CONFIG_OUTPUT */
+		fp = fopen(f, "r");
+
 	if (!fp) {
 		return;
 	}
+	DBGP("reading contents from config file '%s'", f);
 
 	while (!feof(fp)) {
 		char buf[256], *p, *p2, *name, *value;
@@ -8649,7 +8661,13 @@ int main(int argc, char **argv)
 
 		/* No readable config found */
 		if (!current_config) {
+#ifdef CONFIG_OUTPUT
+			current_config = strdup("==builtin==");
+			ERR("no readable personal or system-wide config file found,"
+					" using builtin default");
+#else
 			CRIT_ERR("no readable personal or system-wide config file found");
+#endif /* ! CONF_OUTPUT */
 		}
 	}
 

text2c.sh

@@ -23,9 +23,9 @@
 # $2: output file
 # $3: name of variable
 #
-# The output will be a char **, with each field containing a single line of $1
-# additionally, a macro with the name print_$3 will be defined, with acts as
-# a parameter-less function, printing the text to stdout
+# The output will be a char **, with each field containing a single line of $1.
+# Additionally, a macro with the name print_$3 will be defined, with acts as
+# a parameter-less function, printing the text to stdout.
 
 [ $# -eq 3 ] || {
 	echo "Usage: `basename $0` <inputfile> <outputfile> <variablename>"
@@ -37,14 +37,14 @@ outupper="`basename "$2" | tr '[a-z-.]' '[A-Z__]'`"
 (
 	printf "#ifndef __%s\n" "$outupper"
 	printf "#define __%s\n" "$outupper"
-	printf "const char *%s[] = {\n" "$3"
-	sed -e 's/"/\\"/g' -e 's/^/"/' -e 's/$/",/' $1
-	printf "NULL };\n"
-	printf "#define print_%s() { \\" $3
-	printf "\n\tconst char **__s = %s; \\" $3
-	printf "\n\tfor (; *__s; __s++) \\"
-	printf "\n\t\tputs(*__s); \\"
-	printf "\n}\n"
+	printf "\n#define %s { \\" $3
+	printf "\n"
+	sed -e 's/"/\\"/g' -e 's/^/"/' -e 's/$/\\n", \\/' $1
+	printf "NULL }\n"
+	printf "\n#define print_%s() { \\" $3
+	printf "\n\tconst char **__sp, *__s[] = %s; \\" $3
+	printf "\n\tfor (__sp = __s; *__sp; __sp++) \\"
+	printf "\n\t\tprintf(\"%s\", *__sp); \\" "%s"
+	printf "\n}\n\n"
 	printf "#endif /* __%s */\n" "$outupper"
 ) > $2
-