Add configuration file support.

1 files changed, 235 insertions, 0 deletions

diff --git a/src/config-ini.c b/src/config-ini.c
new file mode 100644
index 0000000..01ba99c
--- /dev/null
+++ b/src/config-ini.c
@@ -0,0 +1,235 @@
+/* config-ini.c -- INI config file parser
+   This file is part of Redshift.
+
+   Redshift is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Redshift is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Redshift.  If not, see <http://www.gnu.org/licenses/>.
+
+   Copyright (c) 2010  Jon Lund Steffensen <jonlst@gmail.com>
+*/
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include "config-ini.h"
+
+#ifdef ENABLE_NLS
+# include <libintl.h>
+# define _(s) gettext(s)
+#else
+# define _(s) s
+#endif
+
+#define MAX_CONFIG_PATH  4096
+#define MAX_LINE_LENGTH   512
+
+
+static FILE *
+open_config_file(const char *filepath)
+{
+	if (filepath == NULL) {
+		char cp[MAX_CONFIG_PATH];
+		char *env;
+
+		if ((env = getenv("XDG_CONFIG_HOME")) != NULL &&
+		    env[0] != '\0') {
+			snprintf(cp, sizeof(cp), "%s/redshift.conf", env);
+			filepath = cp;
+		} else if ((env = getenv("HOME")) != NULL && env[0] != '\0') {
+			snprintf(cp, sizeof(cp),
+				 "%s/.config/redshift.conf", env);
+			filepath = cp;
+		}
+
+		if (filepath != NULL) {
+			FILE *f = fopen(filepath, "r");
+			if (f != NULL) return f;
+			else if (f == NULL && errno != ENOENT) return NULL;
+		}
+
+		/* TODO look in getenv("XDG_CONFIG_DIRS") */
+	} else {
+		FILE *f = fopen(filepath, "r");
+		if (f == NULL) {
+			perror("fopen");
+			return NULL;
+		}
+	}
+
+	return NULL;
+}
+
+int
+config_ini_init(config_ini_state_t *state, const char *filepath)
+{
+	config_ini_section_t *section = NULL;
+	state->sections = NULL;
+
+	FILE *f = open_config_file(filepath);
+	if (f == NULL) {
+		/* Only a serious error if a file was explicitly requested. */
+		if (filepath != NULL) return -1;
+		return 0;
+	}
+
+	char line[MAX_LINE_LENGTH];
+	char *s;
+
+	while (1) {
+		/* Handle the file input linewise. */
+		char *r = fgets(line, sizeof(line), f);
+		if (r == NULL) break;
+
+		/* Strip leading blanks and trailing newline. */
+		s = line + strspn(line, " \t");
+		s[strcspn(s, "\r\n")] = '\0';
+
+		/* Skip comments and empty lines. */
+		if (s[0] == ';' || s[0] == '\0') continue;
+
+		if (s[0] == '[') {
+			/* Read name of section. */
+			const char *name = s+1;
+			char *end = strchr(s, ']');
+			if (end == NULL || end[1] != '\0' || end == name) {
+				fputs(_("Malformed section header in config"
+					" file.\n"), stderr);
+				fclose(f);
+				config_ini_free(state);
+				return -1;
+			}
+
+			*end = '\0';
+
+			/* Create section. */
+			section = malloc(sizeof(config_ini_section_t));
+			if (section == NULL) {
+				fclose(f);
+				config_ini_free(state);
+				return -1;
+			}
+
+			/* Insert into section list. */
+			section->name = NULL;
+			section->settings = NULL;
+			section->next = state->sections;
+			state->sections = section;
+
+			/* Copy section name. */
+			section->name = malloc(end - name + 1);
+			if (section->name == NULL) {
+				fclose(f);
+				config_ini_free(state);
+				return -1;
+			}
+
+			memcpy(section->name, name, end - name + 1);
+		} else {
+			/* Split assignment at equals character. */
+			char *end = strchr(s, '=');
+			if (end == NULL || end == s) {
+				fputs(_("Malformed assignment in config"
+					" file.\n"), stderr);
+				fclose(f);
+				config_ini_free(state);
+				return -1;
+			}
+
+			*end = '\0';
+			char *value = end + 1;
+
+			if (section == NULL) {
+				fputs(_("Assignment outside section in config"
+					" file.\n"), stderr);
+				fclose(f);
+				config_ini_free(state);
+				return -1;
+			}
+
+			/* Create section. */
+			config_ini_setting_t *setting =
+				malloc(sizeof(config_ini_setting_t));
+			if (setting == NULL) {
+				fclose(f);
+				config_ini_free(state);
+				return -1;
+			}
+			
+			/* Insert into section list. */
+			setting->name = NULL;
+			setting->value = NULL;
+			setting->next = section->settings;
+			section->settings = setting;
+
+			/* Copy name of setting. */
+			setting->name = malloc(end - s + 1);
+			if (setting->name == NULL) {
+				fclose(f);
+				config_ini_free(state);
+				return -1;
+			}
+
+			memcpy(setting->name, s, end - s + 1);
+
+			/* Copy setting value. */
+			size_t value_len = strlen(value) + 1;
+			setting->value = malloc(value_len);
+			if (setting->value == NULL) {
+				fclose(f);
+				config_ini_free(state);
+				return -1;
+			}
+
+			memcpy(setting->value, value, value_len);
+		}
+	}
+
+	fclose(f);
+
+	return 0;
+}
+
+void
+config_ini_free(config_ini_state_t *state)
+{
+	config_ini_section_t *section = state->sections;
+
+	while (section != NULL) {
+		config_ini_setting_t *setting = section->settings;
+
+		while (setting != NULL) {
+			free(setting->name);
+			free(setting->value);
+			setting = setting->next;
+		}
+
+		free(section->name);
+		section = section->next;
+	}
+}
+
+config_ini_section_t *
+config_ini_get_section(config_ini_state_t *state, const char *name)
+{
+	config_ini_section_t *section = state->sections;
+	while (section != NULL) {
+		if (strcasecmp(section->name, name) == 0) {
+			return section;
+		}
+		section = section->next;
+	}
+
+	return NULL;
+}