Add libfonts_get_font_root_dirs

Signed-off-by: Mattias Andrée <maandree@kth.se>

4 files changed, 160 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index 185f639..a76310f 100644
--- a/Makefile
+++ b/Makefile
@@ -25,6 +25,7 @@ PUBLIC_OBJ =\
 	libfonts_get_default_font.o\
 	libfonts_get_default_font_name.o\
 	libfonts_get_default_rendering_settings.o\
+	libfonts_get_font_root_dirs.o\
 	libfonts_get_output_dpi.o\
 	libfonts_get_output_rendering_settings.o\
 	libfonts_get_subpixel_order_class.o\
diff --git a/libfonts.h b/libfonts.h
index 20a0b5d..a02bc19 100644
--- a/libfonts.h
+++ b/libfonts.h
@@ -1660,6 +1660,26 @@ extern const char *const libfonts_used_environs[];
 
 
 /**
+ * Get a list of all font root directories, for example
+ * /usr/share/fonts and /usr/local/share/fonts, but not
+ * their subdirectories
+ * 
+ * @param   dirsp   Output parameter for the directory list;
+ *                  note that directories are not necessarily unique
+ *                  (however no two returned strings will be identical)
+ *                  nor do they necessarily exist
+ * @param   countp  Output parameter for the number of listed directories
+ * @param   ctx     Optional `struct libfonts_context`
+ * @return          0 on success, -1 on failure
+ * 
+ * Unless `*dirsp == NULL` (only happens on failure), `(*dirsp)[*dirsp] == NULL`
+ */
+int libfonts_get_font_root_dirs(char ***, size_t *, struct libfonts_context *);
+
+/* TODO add font listing */
+
+
+/**
  * Get the font a default font name aliases to
  * 
  * @param   font  The default font
diff --git a/libfonts_get_font_root_dirs.c b/libfonts_get_font_root_dirs.c
new file mode 100644
index 0000000..1ebbb96
--- /dev/null
+++ b/libfonts_get_font_root_dirs.c
@@ -0,0 +1,138 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+
+static int
+add_dirn(char ***dirsp, size_t *countp, size_t *sizep, const char *part1, size_t part1_len, const char *part2, size_t part2_len)
+{
+	char *dir, **new;
+	size_t i;
+
+	if (*countp == *sizep) {
+		if (SIZE_MAX / sizeof(**dirsp) - 8)
+			goto enomem;
+		new = realloc(*dirsp, (*sizep + 8) * sizeof(**dirsp));
+		if (!new)
+			goto enomem;
+		*dirsp = new;
+		*sizep += 8;
+	}
+
+	dir = malloc(part1_len + part2_len + 1);
+	if (!dir) {
+	enomem:
+		errno = ENOMEM;
+		return -1;
+	}
+
+	memcpy(dir, part1, part1_len);
+	memcpy(&dir[part1_len], part2, part2_len + 1);
+
+	for (i = 0; i < *countp; i++) {
+		if (!strcmp(dir, (*dirsp)[i])) {
+			free(dir);
+			return 0;
+		}
+	}
+
+	(*dirsp)[(*countp)++] = dir;
+	return 0;
+}
+
+static int
+add_dir(char ***dirsp, size_t *countp, size_t *sizep, const char *part1, const char *part2)
+{
+	return add_dirn(dirsp, countp, sizep, part1, strlen(part1), part2, strlen(part2));
+}
+
+static int
+add_dirs(char ***dirsp, size_t *countp, size_t *sizep, const char *env, const char *part2)
+{
+	size_t part2_len = strlen(part2);
+	char *p;
+
+	for (; (p = strchr(env, ':')); env = &p[1])
+		if (*p != ':')
+			if (add_dirn(dirsp, countp, sizep, env, (size_t)(p - env), part2, part2_len))
+				return -1;
+
+	return *env ? add_dirn(dirsp, countp, sizep, env, strlen(env), part2, part2_len) : 0;
+}
+
+int
+libfonts_get_font_root_dirs(char ***dirsp, size_t *countp, struct libfonts_context *ctx)
+{
+	const char *env;
+	char **new, *home = NULL;
+	size_t size = 0;
+
+	*dirsp = NULL;
+	*countp = 0;
+
+	env = libfonts_getenv__("LIBFONTS_FONT_DIRS", ctx);
+	if (env && *env && add_dirs(dirsp, countp, &size, env, "/fonts"))
+		goto fail;
+
+	env = libfonts_getenv__("XDG_DATA_HOME", ctx);
+	if (env && *env && add_dir(dirsp, countp, &size, env, "/fonts"))
+		goto fail;
+
+	env = libfonts_getenv__("HOME", ctx);
+	if (env && *env && (add_dir(dirsp, countp, &size, env, "/.local/share/fonts") ||
+	                    add_dir(dirsp, countp, &size, env, "/.fonts")))
+		goto fail;
+
+	home = libfonts_gethome__(ctx);
+	if (home && *home && (add_dir(dirsp, countp, &size, env, "/.local/share/fonts") ||
+	                      add_dir(dirsp, countp, &size, env, "/.fonts")))
+		goto fail;
+	free(home);
+	home = NULL;
+
+	env = libfonts_getenv__("XDG_DATA_DIRS", ctx);
+	if (env && *env && add_dirs(dirsp, countp, &size, env, "/fonts"))
+		goto fail;
+
+	if (add_dirs(dirsp, countp, &size, "/usr/local/share", "/fonts"))
+		goto fail;
+	if (add_dirs(dirsp, countp, &size, "/usr/share", "/fonts"))
+		goto fail;
+
+	if (*countp == size) {
+		if (SIZE_MAX / sizeof(**dirsp) - 1)
+			goto enomem;
+		new = realloc(*dirsp, (size + 1) * sizeof(**dirsp));
+		if (!new)
+			goto enomem;
+		*dirsp = new;
+	}
+	(*dirsp)[*countp] = NULL;
+
+	return 0;
+
+enomem:
+	errno = ENOMEM;
+fail:
+	if (dirsp)
+		while (*countp)
+			free((*dirsp)[--*countp]);
+	free(*dirsp);
+	free(home);
+	*dirsp = NULL;
+	*countp = 0;
+	return -1;
+}
+
+
+#else
+
+
+int
+main(void)
+{
+	return 0; /* XXX add test */
+}
+
+
+#endif
diff --git a/libfonts_used_environs.c b/libfonts_used_environs.c
index 54232b4..1ce3c39 100644
--- a/libfonts_used_environs.c
+++ b/libfonts_used_environs.c
@@ -7,6 +7,7 @@ const char *const libfonts_used_environs[] = {
 	"LIBFONTS_DEFAULT_SANS_SERIF",
 	"LIBFONTS_DEFAULT_SERIF",
 	"LIBFONTS_DEFAULT_MONOSPACE",
+	"LIBFONTS_FONT_DIRS",
 	"XDG_CONFIG_HOME",
 	"HOME",
 	NULL