Misc improvements

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

21 files changed, 791 insertions, 749 deletions

diff --git a/src/colorramp.c b/src/colorramp.c
index d260b2c..5cdf05f 100644
--- a/src/colorramp.c
+++ b/src/colorramp.c
@@ -1,23 +1,23 @@
 /* colorramp.c -- color temperature calculation source
-   This file is part of redshift-ng.
-
-   redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
-
-   Copyright (c) 2013, 2014  Jon Lund Steffensen <jonlst@gmail.com>
-   Copyright (c) 2013        Ingo Thies <ithies@astro.uni-bonn.de> [historical, no longer applies]
-   Copyright (c) 2016, 2025  Mattias Andrée <m@maandree.se>
-*/
+ * This file is part of redshift-ng.
+ * 
+ * redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * Copyright (c) 2013, 2014  Jon Lund Steffensen <jonlst@gmail.com>
+ * Copyright (c) 2013        Ingo Thies <ithies@astro.uni-bonn.de> [historical, no longer applies]
+ * Copyright (c) 2016, 2025  Mattias Andrée <m@maandree.se>
+ */
 #include "common.h"
 
 #if defined(__GNUC__)
@@ -41,7 +41,7 @@
 	{\
 		size_t i;\
 		double v;\
-		brightness /= size;\
+		brightness /= (size - 1U);\
 		if (gamma == 1.0) {\
 			brightness *= (MAX);\
 			for (i = 0; i < size; i++)\
diff --git a/src/common.h b/src/common.h
index 68fe931..37f56f0 100644
--- a/src/common.h
+++ b/src/common.h
@@ -1,22 +1,22 @@
 /* common.h -- Common header file for Redshift source files
-   This file is part of redshift-ng.
-
-   redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
-
-   Copyright (c) 2009-2017               Jon Lund Steffensen <jonlst@gmail.com>
-   Copyright (c) 2014, 2015, 2016, 2025  Mattias Andrée <m@maandree.se>
-*/
+ * This file is part of redshift-ng.
+ * 
+ * redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * Copyright (c) 2009-2017               Jon Lund Steffensen <jonlst@gmail.com>
+ * Copyright (c) 2014, 2015, 2016, 2025  Mattias Andrée <m@maandree.se>
+ */
 #ifndef REDSHIFT_COMMON_H
 #define REDSHIFT_COMMON_H
 
@@ -65,8 +65,16 @@
 #define _(s) gettext(s)
 #define N_(s) s
 
+#if defined(__GNUC__)
+# define GCC_ONLY(...) __VA_ARGS__
+#else
+# define GCC_ONLY(...)
+#endif
+
 
-/* The color temperature when no adjustment is applied. */
+/**
+ * The colour temperature corresponding to no effect
+ */
 #define NEUTRAL_TEMP  6500
 
 
@@ -238,11 +246,31 @@ LIST_RAMPS_STOP_VALUE_TYPES(X, ;);
 #undef X
 
 
-int config_ini_init(struct config_ini_state *state, const char *filepath);
+/**
+ * Load the configuration file
+ * 
+ * @param  state  Output parameter for the configurations
+ * @param  path   The path to the configuration file, or `NULL` if the
+ *                application should look for it in the default paths
+ */
+void config_ini_init(struct config_ini_state *state, const char *path);
+
+/**
+ * Deallocate the settings loaded
+ * from the configurations file
+ * 
+ * @param  state  The configurations
+ */
 void config_ini_free(struct config_ini_state *state);
-#if defined(__GNUC__)
-__attribute__((__pure__))
-#endif
+
+/**
+ * Get a section from the configuration file
+ * 
+ * @param   state  The configurations
+ * @param   name   The name of the section
+ * @return         The section; `NULL` if missing
+ */
+GCC_ONLY(__attribute__((__pure__)))
 struct config_ini_section *config_ini_get_section(struct config_ini_state *state, const char *name);
 
 
@@ -259,6 +287,14 @@ void options_set_defaults(struct options *options);
 void hooks_signal_period_change(enum period prev_period, enum period period);
 
 
+/**
+ * Create a pipe(7) where both ends have O_NONBLOCK applied
+ * 
+ * @param   Output parameter for the pipe's file descriptors:
+ *          0) reading file descriptor, and
+ *          1) writing file descriptor.
+ * @return  0 on success, -1 on failure
+ */
 int pipeutils_create_nonblocking(int pipefds[2]);
 
 void pipeutils_signal(int write_fd);
@@ -271,7 +307,21 @@ extern volatile sig_atomic_t disable;
 void signals_install_handlers(void);
 
 
-int systemtime_get_time(double *now);
+/**
+ * Get the current time in seconds since the Unix epoch
+ *
+ * @return  The current time
+ */
+double systemtime_get_time(void);
+
+/**
+ * Suspend the process for a short time
+ *
+ * The process may be resumed earily, specifically
+ * if it receives a signal
+ * 
+ * @param  msecs  The number of milliseconds to sleep
+ */
 void systemtime_msleep(unsigned int msecs);
 
 
diff --git a/src/config-ini.c b/src/config-ini.c
index df7d1a1..db94f22 100644
--- a/src/config-ini.c
+++ b/src/config-ini.c
@@ -1,257 +1,332 @@
 /* config-ini.c -- INI config file parser
-   This file is part of redshift-ng.
+ * This file is part of redshift-ng.
+ * 
+ * redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * Copyright (c) 2010-2018  Jon Lund Steffensen <jonlst@gmail.com>
+ * Copyright (c) 2025       Mattias Andrée <m@maandree.se>
+ */
+#include "common.h"
 
-   redshift-ng 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-ng 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.
+/**
+ * Specification for a path that consists of a two parts:
+ * the first being defined by the environment, and the
+ * seocnd being a static string
+ */
+struct env_path {
+	/**
+	 * Whether the environment variable referenced by `.prefix`
+	 * should be split at each colon (:) into multiple paths to
+	 * test
+	 */
+	int multidir_env;
+
+	/**
+	 * Environment variable to use as the first part of the path
+	 * 
+	 * `NULL` if the user's home directory should be used
+	 * 
+	 * The empty string if `.suffix` should be used as is
+	 */
+	const char *prefix_env;
+
+	/**
+	 * The second part of the path
+	 */
+	const char *suffix;
+};
+
+
+/**
+ * Paths, in order of priority, to test when looking for
+ * the configuration file for redshift
+ */
+static const struct env_path paths[] = {
+	{0, "XDG_CONFIG_HOME", "/redshift-ng/redshift.conf"},
+	{0, "XDG_CONFIG_HOME", "/redshift/redshift.conf"},
+	{0, "XDG_CONFIG_HOME", "/redshift.conf"},
+#ifdef WINDOWS
+	{0, "localappdata", "/redshift-ng/redshift.conf"},
+	{0, "localappdata", "/redshift/redshift.conf"},
+	{0, "localappdata", "/redshift.conf"},
+#endif
+	{0, "HOME", "/.config/redshift-ng/redshift.conf"},
+	{0, "HOME", "/.config/redshift/redshift.conf"},
+	{0, "HOME", "/.config/redshift.conf"},
+	{0, "HOME", "/.redshift.conf"},
+	{0, NULL, "/.config/redshift-ng/redshift.conf"},
+	{0, NULL, "/.config/redshift/redshift.conf"},
+	{0, NULL, "/.config/redshift.conf"},
+	{0, NULL, "/.redshift.conf"},
+	{1, "XDG_CONFIG_DIRS", "/redshift-ng/redshift.conf"},
+	{1, "XDG_CONFIG_DIRS", "/redshift/redshift.conf"},
+	{1, "XDG_CONFIG_DIRS", "/redshift.conf"},
+	{0, "", "/etc/redshift-ng/redshift.conf"},
+	{0, "", "/etc/redshift/redshift.conf"},
+	{0, "", "/etc/redshift.conf"}
+};
+
+
+/**
+ * Remove trailing whitespace
+ * 
+ * @param   s    The string to trim, will be truncated
+ * @param   end  The current end of `s`; will be looked up if `NULL`
+ * @return       `s`
+ */
+static char *
+rtrim(char *s, char *end)
+{
+	end = end ? end : strchr(s, '\0');
+	while (end != s && (end[-1] == ' ' || end[-1] == '\t'))
+		end--;
+	*end = '\0';
+	return s;
+}
 
-   You should have received a copy of the GNU General Public License
-   along with redshift-ng.  If not, see <http://www.gnu.org/licenses/>.
 
-   Copyright (c) 2010-2018  Jon Lund Steffensen <jonlst@gmail.com>
-   Copyright (c) 2025       Mattias Andrée <m@maandree.se>
-*/
-#include "common.h"
+/**
+ * Remove leading whitespace
+ * 
+ * @param   s  The string to trim (will not be modified)
+ * @return     An offset of `s`
+ */
+GCC_ONLY(__attribute__((__warn_unused_result__)))
+static char *
+ltrim(char *s)
+{
+	return &s[strspn(s, " \t")];
+}
+
 
-#define MAX_CONFIG_PATH  4096
-#define MAX_LINE_LENGTH   512
+/**
+ * Get the user's home directory
+ *
+ * This function looks up the user's home directory
+ * once and caches the result, later calls to this
+ * function will use the cached result
+ * 
+ * @param  The user's home directory; the empty string if not found
+ */
+static const char *
+get_home(void)
+{
+#ifdef WINDOWS
+	return NULL;
+#else
+	static const char *home = NULL;
+	struct passwd *pw;
+	if (!home) {
+		pw = getpwuid(getuid());
+		if (pw) {
+			home = pw->pw_dir;
+			if (home && *home)
+				return home;
+			weprintf(_("Cannot determine your home directory, "
+			           "it is from the system's user table."));
+		} else if (errno) {
+			weprintf("getpwuid:");
+		} else {
+			weprintf(_("Cannot determine your home directory, your"
+			           " user ID is missing from the system's user table."));
+			/* `errno` can either be set to any number of error codes,
+			 * or be zero if the user does not have a passwd entry */
+		}
+		home = "";
+	}
+	return home;
+#endif
+}
 
 
+/**
+ * Search for a file and open it for reading
+ * 
+ * @param   path_spec  Specification for the path to try
+ * @param   path_out   Output parameter for the file path
+ * @return             `FILE` object for the reading the file; `NULL` if not found
+ */
 static FILE *
-open_config_file(const char *filepath)
+try_path(const struct env_path *path_spec, char **path_out)
 {
-	FILE *f = NULL;
-
-	/* If a path is not specified (filepath is NULL) then
-	   the configuration file is searched for in the directories
-	   specified by the XDG Base Directory Specification
-	   <http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html>.
-
-	   If HOME is not set, getpwuid() is consulted for the home directory. On
-	   windows platforms the %localappdata% is used in place of XDG_CONFIG_HOME.
-	*/
-
-	if (filepath == NULL) {
-		char cp[MAX_CONFIG_PATH];
-		char *env;
-
-		if (f == NULL && (env = getenv("XDG_CONFIG_HOME")) != NULL &&
-		    env[0] != '\0') {
-			snprintf(cp, sizeof(cp), "%s/redshift/redshift.conf", env);
-			f = fopen(cp, "r");
-			if (f == NULL) {
-				/* Fall back to formerly used path. */
-				snprintf(cp, sizeof(cp), "%s/redshift.conf", env);
-				f = fopen(cp, "r");
-			}
-		}
+	const char *prefix, *p, *q;
+	char *path;
+	size_t len;
+	FILE *f;
 
-#ifdef WINDOWS
-		if (f == NULL && (env = getenv("localappdata")) != NULL &&
-		    env[0] != '\0') {
-			snprintf(cp, sizeof(cp), "%s\\redshift.conf", env);
-			f = fopen(cp, "r");
-		}
+	if (!path_spec->prefix_env)
+		prefix = get_home();
+	else if (!*path_spec->prefix_env)
+		return fopen(path_spec->suffix, "r");
+	else
+		prefix = getenv(path_spec->prefix_env);
+	if (!prefix || !*prefix)
+		return NULL;
+
+	path = emalloc(strlen(prefix) + strlen(path_spec->suffix) + 1U);
+
+	if (path_spec->multidir_env) {
+		for (p = prefix; *p; p = &q[!!*q]) {
+#ifdef strchrnul
+			q = strchrnul(p, ':');
+#else
+			q = strchr(p, ':');
+			q = q ? q : strchr(p, '\0');
 #endif
-		if (f == NULL && (env = getenv("HOME")) != NULL &&
-		    env[0] != '\0') {
-			snprintf(cp, sizeof(cp), "%s/.config/redshift/redshift.conf", env);
-			f = fopen(cp, "r");
-			if (f == NULL) {
-				/* Fall back to formerly used path. */
-				snprintf(cp, sizeof(cp), "%s/.config/redshift.conf", env);
-				f = fopen(cp, "r");
-			}
-		}
-#ifndef WINDOWS
-
-		if (f == NULL) {
-			struct passwd *pwd = getpwuid(getuid());
-			if (pwd != NULL) {
-				char *home = pwd->pw_dir;
-				if ((home != NULL) && (*home != '\0')) {
-					snprintf(cp, sizeof(cp), "%s/.config/redshift/redshift.conf", home);
-					f = fopen(cp, "r");
-					if (!f) {
-						/* Fall back to formerly used path. */
-						snprintf(cp, sizeof(cp), "%s/.config/redshift.conf", home);
-						f = fopen(cp, "r");
-					}
-				} else {
-					weprintf(_("Cannot determine your home directory,"
-					           " it is from the system's user table."));
-				}
-			} else if (errno) {
-				weprintf("getpwuid:");
-			} else {
-				weprintf(_("Cannot determine your home directory, your"
-				           " user ID is missing from the system's user table."));
-				/* errno can either be set to any number of error codes,
-				   or be zero if the user does not have a passwd entry. */
+			len = (size_t)(q - p);
+			if (!len)
+				continue;
+
+			memcpy(path, p, len);
+			stpcpy(&path[len], path_spec->suffix);
+			f = fopen(path, "r");
+			if (f) {
+				weprintf(_("Found configuration file `%s'."));
+				break;
+			} else if (errno != ENOENT) {
+				eprintf("fopen %s \"%s\":", path);
 			}
 		}
+	} else {
+		stpcpy(stpcpy(path, prefix), path_spec->suffix);
+		f = fopen(path, "r");
+		if (f)
+			weprintf(_("Found configuration file `%s'."));
+		else if (errno != ENOENT)
+			eprintf("fopen %s \"%s\":", path);
+	}
 
-		if (f == NULL && (env = getenv("XDG_CONFIG_DIRS")) != NULL && *env) {
-			char *begin = env;
-			char *end;
-			int len;
-			for (;;) {
-				end = strchr(begin, ':');
-				if (end == NULL) end = strchr(begin, '\0');
-
-				len = (int)(end - begin);
-				if (len > 0) {
-					snprintf(cp, sizeof(cp), "%.*s/redshift/redshift.conf", len, begin);
-					f = fopen(cp, "r");
-					if (f == NULL) {
-						/* Fall back to formerly used path. */
-						snprintf(cp, sizeof(cp), "%.*s/redshift.conf", len, begin);
-						f = fopen(cp, "r");
-					}
-					if (f != NULL)
-						break;
-				}
-
-				if (*end)
-					break;
-				begin = &end[1];
-			}
-		}
+	if (f) {
+		*path_out = path;
+	} else {
+		free(path);
+		*path_out = NULL;
+	}
+	return f;
+}
 
-		if (f == NULL) {
-			snprintf(cp, sizeof(cp), "%s/redshift.conf", "/etc");
-			f = fopen(cp, "r");
-		}
-#endif
+
+/**
+ * Open the configuration file for reading
+ * 
+ * @param   path         The path to the configuration file, or `NULL` if the
+ *                       application should look for it in the default paths
+ * @param   path_out     Output parameter for the configuration file
+ * @param   pathbuf_out  Output parameter for the memory allocation for `*path_out`;
+ *                       will be set to `NULL` unless `path` is `NULL`
+ * @return               `FILE` object for the reading the file; `NULL` if not
+ *                       found and `path` is `NULL`
+ */
+static FILE *
+open_config_file(const char *path, const char **path_out, char **pathbuf_out)
+{
+	FILE *f = NULL;
+	size_t i;
+
+	if (!path) {
+		for (i = 0; !f && i < ELEMSOF(paths); i++)
+			f = try_path(&paths[i], pathbuf_out);
+		if (!f)
+			weprintf(_("No configuration file found."));
+		*path_out = *pathbuf_out;
 	} else {
-		f = fopen(filepath, "r");
-		if (f == NULL) {
-			weprintf("fopen:");
-			return NULL;
-		}
+		f = fopen(path, "r");
+		if (!f)
+			eprintf("fopen %s \"r\":", path);
+		*path_out = path;
+		*pathbuf_out = NULL;
 	}
 
 	return f;
 }
 
-int
-config_ini_init(struct config_ini_state *state, const char *filepath)
+
+void
+config_ini_init(struct config_ini_state *state, const char *path)
 {
 	struct config_ini_section *section = NULL;
-	char line[MAX_LINE_LENGTH];
-	char *s;
+	struct config_ini_setting *setting;
+	char *line = NULL, *s, *p, *value, *end, *pathbuf;
+	char *next_line = NULL, *name;
+	size_t size = 0;
+	ssize_t len;
 	FILE *f;
 
 	state->sections = NULL;
 
-	f = open_config_file(filepath);
-	if (f == NULL) {
-		/* Only a serious error if a file was explicitly requested. */
-		return filepath ? 0 : -1;
-	}
+	f = open_config_file(path, &path, &pathbuf);
+	if (!f)
+		return;
+	while ((s = next_line) || (len = getline(&line, &size, f)) >= 0) {
+		if (!s && (s = line, strlen(s) != (size_t)len))
+			eprintf(_("Config file contains NUL byte."));
+
+		s = ltrim(s);
+		next_line = NULL;
+		end = &s[strcspn(s, "\r\n")];
+		if (*end) {
+			p = end;
+			do {
+				*p++ = '\0';
+			} while (*p == '\r' || *p == '\n');
+			if (*p)
+				next_line = p;
+		}
+		rtrim(s, end);
 
-	for (;;) {
-		/* Handle the file input linewise. */
-		char *r = fgets(line, sizeof(line), f);
-		if (!r)
+		switch (*s) {
+		case ';': /* comment line */
+		case '#': /* comment line */
+		case '\0': /* blank line */
 			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] == '#' || 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) {
-				weprintf(_("Malformed section header in config file."));
-				fclose(f);
-				config_ini_free(state);
-				return -1;
-			}
-
+		case '[': /* "[%s]", section */
+			end = strchr(name = &s[1], ']');
+			if (!end || end[1] || end == name)
+				eprintf(_("Malformed section header in config file."));
 			*end = '\0';
-
-			/* Create section. */
 			section = emalloc(sizeof(*section));
-
-			/* Insert into section list. */
-			section->name = NULL;
+			section->name = estrdup(name);
 			section->settings = NULL;
 			section->next = state->sections;
 			state->sections = section;
+			break;
 
-			/* 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 {
-			char *value, *end;
-			size_t value_len;
-			struct config_ini_setting *setting;
-
-			/* Split assignment at equals character. */
-			end = strchr(s, '=');
-			if (!end || end == s) {
-				weprintf(_("Malformed assignment in config file."));
-				fclose(f);
-				config_ini_free(state);
-				return -1;
-			}
-
-			*end++ = '\0';
-			value = end;
-
-			if (!section) {
-				weprintf(_("Assignment outside section in config file."));
-				fclose(f);
-				config_ini_free(state);
-				return -1;
-			}
-
-			/* Create section. */
+		default: /* "%s = %s", name, value */
+			value = p = strchr(name = s, '=');
+			if (!value || value == name)
+				eprintf(_("Malformed assignment in config file."));
+			*value++ = '\0';
+			if (!section)
+				eprintf(_("Assignment outside section in config file."));
 			setting = emalloc(sizeof(*setting));
-
-			/* Insert into section list. */
-			setting->name = NULL;
-			setting->value = NULL;
+			setting->name = estrdup(rtrim(name, p));
+			setting->value = estrdup(rtrim(ltrim(value), NULL));
 			setting->next = section->settings;
 			section->settings = setting;
-
-			/* Copy name of setting. */
-			setting->name = emalloc(end - s);
-
-			memcpy(setting->name, s, end - s);
-
-			/* Copy setting value. */
-			value_len = strlen(value) + 1;
-			setting->value = emalloc(value_len);
-
-			memcpy(setting->value, value, value_len);
+			break;
 		}
 	}
-
+	if (ferror(f))
+		eprintf("getline %s:", path);
+	free(pathbuf);
+	free(line);
 	fclose(f);
-
-	return 0;
 }
 
+
 void
 config_ini_free(struct config_ini_state *state)
 {
@@ -270,6 +345,7 @@ config_ini_free(struct config_ini_state *state)
 	}
 }
 
+
 struct config_ini_section *
 config_ini_get_section(struct config_ini_state *state, const char *name)
 {
diff --git a/src/gamma-coopgamma.c b/src/gamma-coopgamma.c
index 61494af..0dd47c5 100644
--- a/src/gamma-coopgamma.c
+++ b/src/gamma-coopgamma.c
@@ -1,21 +1,21 @@
 /* gamma-coopgamma.h -- coopgamma gamma adjustment source
-   This file is part of redshift-ng.
-
-   redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
-
-   Copyright (c) 2016, 2025  Mattias Andrée <m@maandree.se>
-*/
+ * This file is part of redshift-ng.
+ * 
+ * redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * Copyright (c) 2016, 2025  Mattias Andrée <m@maandree.se>
+ */
 #include "common.h"
 
 #include <libcoopgamma.h>
diff --git a/src/gamma-drm.c b/src/gamma-drm.c
index 47edd08..877e2a9 100644
--- a/src/gamma-drm.c
+++ b/src/gamma-drm.c
@@ -1,22 +1,22 @@
 /* gamma-drm.c -- DRM gamma adjustment source
-   This file is part of redshift-ng.
-
-   redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
-
-   Copyright (c) 2014, 2025  Mattias Andrée <m@maandree.se>
-   Copyright (c) 2017        Jon Lund Steffensen <jonlst@gmail.com>
-*/
+ * This file is part of redshift-ng.
+ * 
+ * redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * Copyright (c) 2014, 2025  Mattias Andrée <m@maandree.se>
+ * Copyright (c) 2017        Jon Lund Steffensen <jonlst@gmail.com>
+ */
 #include "common.h"
 
 #include <xf86drm.h>
@@ -79,9 +79,8 @@ drm_start(struct gamma_state *state, enum program_mode mode)
 
 	state->fd = open(pathname, O_RDWR | O_CLOEXEC);
 	if (state->fd < 0) {
-		/* TODO check if access permissions, normally root or
-		        membership of the video group is required. */
-		weprintf(_("Failed to open DRM device `%s':"), pathname);
+		/* TODO check if access permissions, normally root or membership of the video group is required. */
+		weprintf(_("Failed to open DRM device `%s': %s."), pathname, strerror(errno));
 		return -1;
 	}
 
@@ -99,9 +98,9 @@ drm_start(struct gamma_state *state, enum program_mode mode)
 	if (state->crtc_num >= 0) {
 		if (state->crtc_num >= crtc_count) {
 			if (crtc_count > 1)
-				weprintf(_("CRTC %i does not exist, valid CRTCs are [0-%i].\n"), state->crtc_num, crtc_count-1);
+				weprintf(_("CRTC %i does not exist, valid CRTCs are [0, %i]."), state->crtc_num, crtc_count-1);
 			else
-				weprintf(_("CRTC %i does not exist, only CRTC 0 exists.\n"), state->crtc_num);
+				weprintf(_("CRTC %i does not exist, only CRTC 0 exists."), state->crtc_num);
 			close(state->fd);
 			state->fd = -1;
 			drmModeFreeResources(state->res);
diff --git a/src/gamma-dummy.c b/src/gamma-dummy.c
index a9aea66..cc494e4 100644
--- a/src/gamma-dummy.c
+++ b/src/gamma-dummy.c
@@ -1,21 +1,21 @@
 /* gamma-dummy.c -- No-op gamma adjustment
-   This file is part of redshift-ng.
-
-   redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
-
-   Copyright (c) 2013-2017  Jon Lund Steffensen <jonlst@gmail.com>
-*/
+ * This file is part of redshift-ng.
+ * 
+ * redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * Copyright (c) 2013-2017  Jon Lund Steffensen <jonlst@gmail.com>
+ */
 #include "common.h"
 
 
diff --git a/src/gamma-quartz.c b/src/gamma-quartz.c
index da6a57c..4645da2 100644
--- a/src/gamma-quartz.c
+++ b/src/gamma-quartz.c
@@ -1,22 +1,22 @@
 /* gamma-quartz.c -- Quartz (OSX) gamma adjustment
-   This file is part of redshift-ng.
-
-   redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
-
-   Copyright (c) 2014-2017  Jon Lund Steffensen <jonlst@gmail.com>
-   Copyright (c) 2025       Mattias Andrée <m@maandree.se>
-*/
+ * This file is part of redshift-ng.
+ * 
+ * redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * Copyright (c) 2014-2017  Jon Lund Steffensen <jonlst@gmail.com>
+ * Copyright (c) 2025       Mattias Andrée <m@maandree.se>
+ */
 #include "common.h"
 
 #include <ApplicationServices/ApplicationServices.h>
diff --git a/src/gamma-randr.c b/src/gamma-randr.c
index fcb02de..1c648a9 100644
--- a/src/gamma-randr.c
+++ b/src/gamma-randr.c
@@ -1,22 +1,22 @@
 /* gamma-randr.c -- X RANDR gamma adjustment source
-   This file is part of redshift-ng.
-
-   redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
-
-   Copyright (c) 2010-2017  Jon Lund Steffensen <jonlst@gmail.com>
-   Copyright (c) 2025       Mattias Andrée <m@maandree.se>
-*/
+ * This file is part of redshift-ng.
+ * 
+ * redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * Copyright (c) 2010-2017  Jon Lund Steffensen <jonlst@gmail.com>
+ * Copyright (c) 2025       Mattias Andrée <m@maandree.se>
+ */
 #include "common.h"
 
 #include <xcb/xcb.h>
@@ -338,7 +338,7 @@ randr_set_temperature_for_crtc(struct gamma_state *state, int crtc_num,
 
 	if (crtc_num >= state->crtc_count || crtc_num < 0) {
 		if (state->crtc_count > 1)
-			weprintf(_("CRTC %i does not exist, valid CRTCs are [0-%i]."), crtc_num, state->crtc_count-1);
+			weprintf(_("CRTC %i does not exist, valid CRTCs are [0, %i]."), crtc_num, state->crtc_count-1);
 		else
 			weprintf(_("CRTC %i does not exist, only CRTC 0 exists."), crtc_num);
 
diff --git a/src/gamma-vidmode.c b/src/gamma-vidmode.c
index 25252c6..0876f47 100644
--- a/src/gamma-vidmode.c
+++ b/src/gamma-vidmode.c
@@ -1,22 +1,22 @@
 /* gamma-vidmode.c -- X VidMode gamma adjustment source
-   This file is part of redshift-ng.
-
-   redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
-
-   Copyright (c) 2010-2017  Jon Lund Steffensen <jonlst@gmail.com>
-   Copyright (c) 2025       Mattias Andrée <m@maandree.se>
-*/
+ * This file is part of redshift-ng.
+ * 
+ * redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * Copyright (c) 2010-2017  Jon Lund Steffensen <jonlst@gmail.com>
+ * Copyright (c) 2025       Mattias Andrée <m@maandree.se>
+ */
 #include "common.h"
 
 #include <X11/Xlib.h>
diff --git a/src/gamma-w32gdi.c b/src/gamma-w32gdi.c
index 9c5f9ba..ef84744 100644
--- a/src/gamma-w32gdi.c
+++ b/src/gamma-w32gdi.c
@@ -1,22 +1,22 @@
 /* gamma-w32gdi.c -- Windows GDI gamma adjustment source
-   This file is part of redshift-ng.
-
-   redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
-
-   Copyright (c) 2010-2017  Jon Lund Steffensen <jonlst@gmail.com>
-   Copyright (c) 2025       Mattias Andrée <m@maandree.se>
-*/
+ * This file is part of redshift-ng.
+ * 
+ * redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * Copyright (c) 2010-2017  Jon Lund Steffensen <jonlst@gmail.com>
+ * Copyright (c) 2025       Mattias Andrée <m@maandree.se>
+ */
 #ifndef WINVER
 # define WINVER  0x0500
 #endif
diff --git a/src/hooks.c b/src/hooks.c
index 2943eeb..4574742 100644
--- a/src/hooks.c
+++ b/src/hooks.c
@@ -1,21 +1,21 @@
 /* hooks.c -- Hooks triggered by events
-   This file is part of redshift-ng.
-
-   redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
-
-   Copyright (c) 2014  Jon Lund Steffensen <jonlst@gmail.com>
-*/
+ * This file is part of redshift-ng.
+ * 
+ * redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * Copyright (c) 2014  Jon Lund Steffensen <jonlst@gmail.com>
+ */
 #include "common.h"
 
 #define MAX_HOOK_PATH  4096
diff --git a/src/location-corelocation.m b/src/location-corelocation.m
index caf43ce..222abe9 100644
--- a/src/location-corelocation.m
+++ b/src/location-corelocation.m
@@ -1,22 +1,22 @@
 /* location-corelocation.m -- CoreLocation (OSX) location provider source
-   This file is part of redshift-ng.
-
-   redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
-
-   Copyright (c) 2014-2017  Jon Lund Steffensen <jonlst@gmail.com>
-   Copyright (c) 2025       Mattias Andrée <m@maandree.se>
-*/
+ * This file is part of redshift-ng.
+ * 
+ * redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * Copyright (c) 2014-2017  Jon Lund Steffensen <jonlst@gmail.com>
+ * Copyright (c) 2025       Mattias Andrée <m@maandree.se>
+ */
 #include "common.h"
 
 #import <Foundation/Foundation.h>
diff --git a/src/location-geoclue2.c b/src/location-geoclue2.c
index c6e0d4c..f5076c5 100644
--- a/src/location-geoclue2.c
+++ b/src/location-geoclue2.c
@@ -1,22 +1,22 @@
 /* location-geoclue2.c -- GeoClue2 location provider source
-   This file is part of redshift-ng.
-
-   redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
-
-   Copyright (c) 2014-2017  Jon Lund Steffensen <jonlst@gmail.com>
-   Copyright (c) 2025       Mattias Andrée <m@maandree.se>
-*/
+ * This file is part of redshift-ng.
+ * 
+ * redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * Copyright (c) 2014-2017  Jon Lund Steffensen <jonlst@gmail.com>
+ * Copyright (c) 2025       Mattias Andrée <m@maandree.se>
+ */
 #include "common.h"
 
 #include <glib.h>
diff --git a/src/location-manual.c b/src/location-manual.c
index a720ff5..90f30bd 100644
--- a/src/location-manual.c
+++ b/src/location-manual.c
@@ -1,22 +1,22 @@
 /* location-manual.c -- Manual location provider source
-   This file is part of redshift-ng.
-
-   redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
-
-   Copyright (c) 2010-2017  Jon Lund Steffensen <jonlst@gmail.com>
-   Copyright (c) 2025       Mattias Andrée <m@maandree.se>
-*/
+ * This file is part of redshift-ng.
+ * 
+ * redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * Copyright (c) 2010-2017  Jon Lund Steffensen <jonlst@gmail.com>
+ * Copyright (c) 2025       Mattias Andrée <m@maandree.se>
+ */
 #include "common.h"
 
 
diff --git a/src/options.c b/src/options.c
index dfddeda..7629e89 100644
--- a/src/options.c
+++ b/src/options.c
@@ -1,21 +1,21 @@
 /* options.c -- Program options
-   This file is part of redshift-ng.
-
-   redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
-
-   Copyright (c) 2017  Jon Lund Steffensen <jonlst@gmail.com>
-*/
+ * This file is part of redshift-ng.
+ * 
+ * redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * Copyright (c) 2017  Jon Lund Steffensen <jonlst@gmail.com>
+ */
 #include "common.h"
 #include "solar.h"
 
diff --git a/src/pipeutils.c b/src/pipeutils.c
index e6fdf41..7f157c5 100644
--- a/src/pipeutils.c
+++ b/src/pipeutils.c
@@ -1,27 +1,25 @@
 /* pipeutils.c -- Utilities for using pipes as signals
-   This file is part of redshift-ng.
-
-   redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
-
-   Copyright (c) 2017  Jon Lund Steffensen <jonlst@gmail.com>
-   Copyright (c) 2025  Mattias Andrée <m@maandree.se>
-*/
+ * This file is part of redshift-ng.
+ * 
+ * redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * Copyright (c) 2017  Jon Lund Steffensen <jonlst@gmail.com>
+ * Copyright (c) 2025  Mattias Andrée <m@maandree.se>
+ */
 #include "common.h"
 
 
-
-/* Create non-blocking set of pipe fds. */
 int
 pipeutils_create_nonblocking(int pipefds[2])
 {
@@ -67,6 +65,7 @@ fail:
 #endif
 }
 
+
 /* Signal on write-end of pipe. */
 void
 pipeutils_signal(int write_fd)
@@ -74,6 +73,7 @@ pipeutils_signal(int write_fd)
 	write(write_fd, "", 1);
 }
 
+
 /* Mark signal as handled on read-end of pipe. */
 void
 pipeutils_handle_signal(int read_fd)
diff --git a/src/redshift.c b/src/redshift.c
index 70cdf38..ae92c86 100644
--- a/src/redshift.c
+++ b/src/redshift.c
@@ -1,28 +1,28 @@
 /* redshift.c -- Main program source
-   This file is part of redshift-ng.
-
-   redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
-
-   Copyright (c) 2009-2017  Jon Lund Steffensen <jonlst@gmail.com>
-   Copyright (c) 2025       Mattias Andrée <m@maandre.se>
-*/
+ * This file is part of redshift-ng.
+ * 
+ * redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * Copyright (c) 2009-2017  Jon Lund Steffensen <jonlst@gmail.com>
+ * Copyright (c) 2025       Mattias Andrée <m@maandre.se>
+ */
 #include "common.h"
 #include "solar.h"
 
 /* poll.h is not available on Windows but there is no Windows location provider
-   using polling. On Windows, we just define some stubs to make things compile.
-   */
+ * using polling. On Windows, we just define some stubs to make things compile.
+ */
 #ifndef WINDOWS
 # include <poll.h>
 #else
@@ -36,13 +36,13 @@ int poll(struct pollfd *fds, int nfds, int timeout) { abort(); return -1; }
 #endif
 
 /* pause() is not defined on windows platform but is not needed either.
-   Use a noop macro instead. */
+ * Use a noop macro instead. */
 #ifdef WINDOWS
 # define pause()
 #endif
 
 #undef CLAMP
-#define CLAMP(lo,mid,up)  (((lo) > (mid)) ? (lo) : (((mid) < (up)) ? (mid) : (up)))
+#define CLAMP(LO, MID, UP)  (((LO) > (MID)) ? (LO) : (((MID) < (UP)) ? (MID) : (UP)))
 
 
 /* Bounds for parameters. */
@@ -191,9 +191,7 @@ interpolate_color_settings(const struct color_setting *first, const struct color
                            double alpha, struct color_setting *result)
 {
 	int i;
-
 	alpha = CLAMP(0.0, alpha, 1.0);
-
 	result->temperature = (1.0 - alpha) * first->temperature + alpha * second->temperature;
 	result->brightness  = (1.0 - alpha) * first->brightness  + alpha * second->brightness;
 	for (i = 0; i < 3; i++)
@@ -238,10 +236,12 @@ provider_try_start(const struct location_provider *provider, LOCATION_STATE **st
 	const char *manual_keys[] = {"lat", "lon"};
 	struct config_ini_section *section;
 	struct config_ini_setting *setting;
+	char *next_arg, *value;
+	const char *key;
 	int i;
 
 	if (provider->init(state) < 0) {
-		weprintf(_("Initialization of %s failed.\n"), provider->name);
+		weprintf(_("Initialization of %s failed."), provider->name);
 		return -1;
 	}
 
@@ -250,9 +250,9 @@ provider_try_start(const struct location_provider *provider, LOCATION_STATE **st
 		for (setting = section->settings; setting; setting = setting->next) {
 			if (provider->set_option(*state, setting->name, setting->value) < 0) {
 				provider->free(*state);
-				weprintf(_("Failed to set %s option.\n"), provider->name);
+				weprintf(_("Failed to set %s option."), provider->name);
 				/* TRANSLATORS: `help' must not be translated. */
-				weprintf(_("Try `-l %s:help' for more information.\n"), provider->name);
+				weprintf(_("Try `-l %s:help' for more information."), provider->name);
 				return -1;
 			}
 		}
@@ -260,10 +260,6 @@ provider_try_start(const struct location_provider *provider, LOCATION_STATE **st
 
 	/* Set provider options from command line. */
 	for (i = 0; args; i++) {
-		char *next_arg;
-		const char *key;
-		char *value;
-
 		next_arg = strchr(args, ':');
 		if (next_arg)
 			*next_arg++ = '\0';
@@ -279,7 +275,7 @@ provider_try_start(const struct location_provider *provider, LOCATION_STATE **st
 				key = manual_keys[i];
 				value = args;
 			} else {
-				weprintf(_("Failed to parse option `%s'.\n"), args);
+				weprintf(_("Failed to parse option `%s'."), args);
 				return -1;
 			}
 		} else {
@@ -288,9 +284,9 @@ provider_try_start(const struct location_provider *provider, LOCATION_STATE **st
 
 		if (provider->set_option(*state, key, value) < 0) {
 			provider->free(*state);
-			weprintf(_("Failed to set %s option.\n"), provider->name);
+			weprintf(_("Failed to set %s option."), provider->name);
 			/* TRANSLATORS: `help' must not be translated. */
-			weprintf(_("Try `-l %s:help' for more information.\n"), provider->name);
+			weprintf(_("Try `-l %s:help' for more information."), provider->name);
 			return -1;
 		}
 
@@ -313,9 +309,11 @@ method_try_start(const struct gamma_method *method, GAMMA_STATE **state,
 {
 	struct config_ini_section *section;
 	struct config_ini_setting *setting;
+	char *next_arg, *value;
+	const char *key;
 
 	if (method->init(state) < 0) {
-		weprintf(_("Initialization of %s failed.\n"), method->name);
+		weprintf(_("Initialization of %s failed."), method->name);
 		return -1;
 	}
 
@@ -324,37 +322,33 @@ method_try_start(const struct gamma_method *method, GAMMA_STATE **state,
 		for (setting = section->settings; setting; setting = setting->next) {
 			if (method->set_option(*state, setting->name, setting->value) < 0) {
 				method->free(*state);
-				weprintf(_("Failed to set %s option.\n"), method->name);
+				weprintf(_("Failed to set %s option."), method->name);
 				/* TRANSLATORS: `help' must not be translated. */
-				weprintf(_("Try `-m %s:help' for more information.\n"), method->name);
+				weprintf(_("Try `-m %s:help' for more information.\n"), method->name); /* TODO \n */
 				return -1;
 			}
 		}
 	}
 
 	/* Set method options from command line. */
-	while (args != NULL) {
-		char *next_arg;
-		const char *key;
-		char *value;
-
+	while (args) {
 		next_arg = strchr(args, ':');
-		if (next_arg != NULL)
+		if (next_arg)
 			*next_arg++ = '\0';
 
 		key = args;
 		value = strchr(args, '=');
 		if (!value) {
-			weprintf(_("Failed to parse option `%s'.\n"), args);
+			weprintf(_("Failed to parse option `%s'.\n"), args); /* TODO \n */
 			return -1;
 		}
 		*value++ = '\0';
 
 		if (method->set_option(*state, key, value) < 0) {
 			method->free(*state);
-			weprintf(_("Failed to set %s option.\n"), method->name);
+			weprintf(_("Failed to set %s option.\n"), method->name); /* TODO \n */
 			/* TRANSLATORS: `help' must not be translated. */
-			weprintf(_("Try -m %s:help' for more information.\n"), method->name);
+			weprintf(_("Try -m %s:help' for more information.\n"), method->name); /* TODO missing ` and \n */
 			return -1;
 		}
 
@@ -364,7 +358,7 @@ method_try_start(const struct gamma_method *method, GAMMA_STATE **state,
 	/* Start method. */
 	if (method->start(*state, mode) < 0) {
 		method->free(*state);
-		weprintf(_("Failed to start adjustment method %s.\n"), method->name);
+		weprintf(_("Failed to start adjustment method %s.\n"), method->name); /* TODO \n */
 		return -1;
 	}
 
@@ -390,14 +384,14 @@ location_is_valid(const struct location *location)
 	/* Latitude */
 	if (location->lat < MIN_LAT || location->lat > MAX_LAT) {
 		/* TRANSLATORS: Append degree symbols if possible. */
-		weprintf(_("Latitude must be between %.1f and %.1f.\n"), MIN_LAT, MAX_LAT);
+		weprintf(_("Latitude must be between %.1f and %.1f.\n"), MIN_LAT, MAX_LAT); /* TODO \n */
 		return 0;
 	}
 
 	/* Longitude */
 	if (location->lon < MIN_LON || location->lon > MAX_LON) {
 		/* TRANSLATORS: Append degree symbols if possible. */
-		weprintf(_("Longitude must be between %.1f and %.1f.\n"), MIN_LON, MAX_LON);
+		weprintf(_("Longitude must be between %.1f and %.1f.\n"), MIN_LON, MAX_LON); /* TODO \n */
 		return 0;
 	}
 
@@ -420,10 +414,7 @@ provider_get_location(const struct location_provider *provider, LOCATION_STATE *
 		if (loc_fd >= 0) {
 			/* Provider is dynamic. */
 			/* TODO: This should use a monotonic time source. */
-			if (systemtime_get_time(&now) < 0) {
-				weprintf(_("Unable to read system time.\n"));
-				return -1;
-			}
+			now = systemtime_get_time();
 
 			/* Poll on file descriptor until ready. */
 			pollfds[0].fd = loc_fd;
@@ -436,10 +427,7 @@ provider_get_location(const struct location_provider *provider, LOCATION_STATE *
 				return 0;
 			}
 
-			if (systemtime_get_time(&later) < 0) {
-				weprintf(_("Unable to read system time.\n"));
-				return -1;
-			}
+			later = systemtime_get_time();
 
 			/* Adjust timeout by elapsed time */
 			if (timeout >= 0) {
@@ -471,7 +459,7 @@ ease_fade(double t)
    This is the main loop of the continual mode which keeps track of the
    current time and continuously updates the screen to the appropriate
    color temperature. */
-static int
+static void
 run_continual_mode(const struct location_provider *provider,
 		   LOCATION_STATE *location_state,
 		   const struct transition_scheme *scheme,
@@ -508,18 +496,14 @@ run_continual_mode(const struct location_provider *provider,
 	loc = (struct location){ NAN, NAN };
 	need_location = !scheme->use_time;
 	if (need_location) {
-		weprintf(_("Waiting for initial location to become available...\n"));
+		weprintf(_("Waiting for initial location to become available...\n")); /* TODO \n */
 
 		/* Get initial location from provider */
-		if (provider_get_location(provider, location_state, -1, &loc) < 0) {
-			weprintf(_("Unable to get location from provider.\n"));
-			return -1;
-		}
+		if (provider_get_location(provider, location_state, -1, &loc) < 0)
+			eprintf(_("Unable to get location from provider."));
 
-		if (!location_is_valid(&loc)) {
-			weprintf(_("Invalid location returned from provider.\n"));
-			return -1;
-		}
+		if (!location_is_valid(&loc))
+			eprintf(_("Invalid location returned from provider.\n")); /* TODO \n */
 
 		print_location(&loc);
 	}
@@ -545,13 +529,10 @@ run_continual_mode(const struct location_provider *provider,
 
 		/* Check to see if exit signal was caught */
 		if (exiting) {
-			if (done) {
-				/* On second signal stop the ongoing fade. */
-				break;
-			} else {
-				done = 1;
-				disabled = 1;
-			}
+			if (done)
+				break; /* On second signal stop the ongoing fade. */
+			done = 1;
+			disabled = 1;
 			exiting = 0;
 		}
 
@@ -562,10 +543,7 @@ run_continual_mode(const struct location_provider *provider,
 		prev_disabled = disabled;
 
 		/* Read timestamp */
-		if (systemtime_get_time(&now) < 0) {
-			weprintf(_("Unable to read system time.\n"));
-			return -1;
-		}
+		now = systemtime_get_time();
 
 		if (scheme->use_time) {
 			int time_offset = get_seconds_since_midnight(now);
@@ -629,7 +607,8 @@ run_continual_mode(const struct location_provider *provider,
 		}
 
 		/* Break loop when done and final fade is over */
-		if (done && fade_length == 0) break;
+		if (done && fade_length == 0)
+			break;
 
 		if (verbose) {
 			if (prev_target_interp.temperature != target_interp.temperature)
@@ -639,20 +618,15 @@ run_continual_mode(const struct location_provider *provider,
 		}
 
 		/* Adjust temperature */
-		if (method->set_temperature(method_state, &interp, preserve_gamma) < 0) {
-			weprintf(_("Temperature adjustment failed.\n"));
-			return -1;
-		}
+		if (method->set_temperature(method_state, &interp, preserve_gamma) < 0)
+			eprintf(_("Temperature adjustment failed."));
 
 		/* Save period and target color setting as previous */
 		prev_period = period;
 		prev_target_interp = target_interp;
 
 		/* Sleep length depends on whether a fade is ongoing. */
-		delay = SLEEP_DURATION;
-		if (fade_length != 0) {
-			delay = SLEEP_DURATION_SHORT;
-		}
+		delay = fade_length ? SLEEP_DURATION_SHORT : SLEEP_DURATION;
 
 		/* Update location. */
 		loc_fd = need_location ? provider->get_fd(location_state) : -1;
@@ -670,21 +644,18 @@ run_continual_mode(const struct location_provider *provider,
 				if (errno == EINTR)
 					continue;
 				weprintf("poll:");
-				weprintf(_("Unable to get location from provider.\n"));
-				return -1;
+				eprintf(_("Unable to get location from provider."));
 			} else if (r == 0) {
 				continue;
 			}
 
 			/* Get new location and availability
 			   information. */
-			if (provider->handle(location_state, &new_loc, &new_available) < 0) {
-				weprintf(_("Unable to get location from provider.\n"));
-				return -1;
-			}
+			if (provider->handle(location_state, &new_loc, &new_available) < 0)
+				eprintf(_("Unable to get location from provider."));
 
 			if (!new_available && new_available != location_available) {
-				weprintf(_("Location is temporarily unavailable; Using previous"
+				weprintf(_("Location is temporarily unavailable; Using previous" /* TODO captial U efter ; and \n*/
 				           " location until it becomes available...\n"));
 			}
 
@@ -698,10 +669,8 @@ run_continual_mode(const struct location_provider *provider,
 
 			location_available = new_available;
 
-			if (!location_is_valid(&loc)) {
-				weprintf(_("Invalid location returned from provider.\n"));
-				return -1;
-			}
+			if (!location_is_valid(&loc))
+				eprintf(_("Invalid location returned from provider."));
 		} else {
 			systemtime_msleep(delay);
 		}
@@ -709,8 +678,6 @@ run_continual_mode(const struct location_provider *provider,
 
 	/* Restore saved gamma ramps */
 	method->restore(method_state);
-
-	return 0;
 }
 
 
@@ -787,8 +754,7 @@ main(int argc, char *argv[])
 	options_parse_args(&options, argc, argv, gamma_methods, location_providers);
 
 	/* Load settings from config file. */
-	if (config_ini_init(&config_state, options.config_filepath) < 0)
-		eprintf(_("Unable to load config file."));
+	config_ini_init(&config_state, options.config_filepath);
 
 	free(options.config_filepath);
 
@@ -962,12 +928,7 @@ main(int argc, char *argv[])
 			print_location(&loc);
 		}
 
-		r = systemtime_get_time(&now);
-		if (r < 0) {
-			weprintf(_("Unable to read system time."));
-			options.method->free(method_state);
-			exit(1);
-		}
+		now = systemtime_get_time();
 
 		if (options.scheme.use_time) {
 			int time_offset = get_seconds_since_midnight(now);
@@ -994,82 +955,45 @@ main(int argc, char *argv[])
 			printf(_("Brightness: %.2f\n"), color.brightness);
 		}
 
-		if (options.mode != PROGRAM_MODE_PRINT) {
-			/* Adjust temperature */
-			if (options.method->set_temperature(method_state, &color, options.preserve_gamma) < 0) {
-				weprintf(_("Temperature adjustment failed."));
-				options.method->free(method_state);
-				exit(EXIT_FAILURE);
-			}
-
-			/* In Quartz (macOS) the gamma adjustments will
-			   automatically revert when the process exits.
-			   Therefore, we have to loop until CTRL-C is received.
-			   */
-			if (!strcmp(options.method->name, "quartz")) {
-				weprintf(_("Press ctrl-c to stop..."));
-				pause();
-			}
-		}
-		break;
+		if (options.mode == PROGRAM_MODE_PRINT)
+			break;
 
-	case PROGRAM_MODE_MANUAL:
-		if (options.verbose)
-			printf(_("Color temperature: %uK\n"), options.temp_set);
-
-		/* Adjust temperature */
-		color = scheme->day;
-		color.temperature = options.temp_set;
-		r = options.method->set_temperature(method_state, &color, options.preserve_gamma);
-		if (r < 0) {
+	apply:
+		if (options.method->set_temperature(method_state, &color, options.preserve_gamma) < 0) {
 			weprintf(_("Temperature adjustment failed."));
 			options.method->free(method_state);
-			exit(EXIT_FAILURE);
+			exit(1);
 		}
 
-		/* In Quartz (OSX) the gamma adjustments will automatically
-		   revert when the process exits. Therefore, we have to loop
-		   until CTRL-C is received. */
+		/* In Quartz (OSX) the gamma adjustments will automatically revert when
+		 * the process exits. Therefore, we have to loop until CTRL-C is received. */
 		if (!strcmp(options.method->name, "quartz")) {
 			weprintf(_("Press ctrl-c to stop..."));
 			pause();
 		}
 		break;
 
+	case PROGRAM_MODE_MANUAL:
+		if (options.verbose)
+			printf(_("Color temperature: %uK\n"), options.temp_set);
+		color = scheme->day;
+		color.temperature = options.temp_set;
+		goto apply;
+
 	case PROGRAM_MODE_RESET:
-		/* Reset screen */
 		color_setting_reset(&color);
-
-		if (options.method->set_temperature(method_state, &color, 0) < 0) {
-			weprintf(_("Temperature adjustment failed."));
-			options.method->free(method_state);
-			exit(EXIT_FAILURE);
-		}
-
-		/* In Quartz (OSX) the gamma adjustments will automatically
-		   revert when the process exits. Therefore, we have to loop
-		   until CTRL-C is received. */
-		if (!strcmp(options.method->name, "quartz")) {
-			weprintf(_("Press ctrl-c to stop..."));
-			pause();
-		}
-		break;
+		options.preserve_gamma = 0;
+		goto apply;
 
 	case PROGRAM_MODE_CONTINUAL:
-		r = run_continual_mode(options.provider, location_state, scheme, options.method, method_state,
-		                       options.use_fade, options.preserve_gamma, options.verbose);
-		if (r < 0)
-			exit(EXIT_FAILURE);
+		run_continual_mode(options.provider, location_state, scheme, options.method, method_state,
+		                   options.use_fade, options.preserve_gamma, options.verbose);
 		break;
 	}
 
-	/* Clean up gamma adjustment state */
 	if (options.mode != PROGRAM_MODE_PRINT)
 		options.method->free(method_state);
-
-	/* Clean up location provider state */
 	if (need_location)
 		options.provider->free(location_state);
-
-	return EXIT_SUCCESS;
+	return 0;
 }
diff --git a/src/signals.c b/src/signals.c
index f0d4966..dec5626 100644
--- a/src/signals.c
+++ b/src/signals.c
@@ -1,22 +1,22 @@
 /* signals.c -- Signal processing source
-   This file is part of redshift-ng.
-
-   redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
-
-   Copyright (c) 2009-2015   Jon Lund Steffensen <jonlst@gmail.com>
-   Copyright (c) 2015, 2025  Mattias Andrée <m@maandree.se>
-*/
+ * This file is part of redshift-ng.
+ * 
+ * redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * Copyright (c) 2009-2015   Jon Lund Steffensen <jonlst@gmail.com>
+ * Copyright (c) 2015, 2025  Mattias Andrée <m@maandree.se>
+ */
 #include "common.h"
 
 
diff --git a/src/solar.c b/src/solar.c
index f70cdc7..784a293 100644
--- a/src/solar.c
+++ b/src/solar.c
@@ -1,27 +1,27 @@
 /* solar.c -- Solar position source
-   This file is part of redshift-ng.
-
-   redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
-
-   Copyright (c) 2010  Jon Lund Steffensen <jonlst@gmail.com>
+ * This file is part of redshift-ng.
+ * 
+ * redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * Copyright (c) 2010  Jon Lund Steffensen <jonlst@gmail.com>
 */
 
 /* Ported from javascript code by U.S. Department of Commerce,
-   National Oceanic & Atmospheric Administration:
-   http://www.srrb.noaa.gov/highlights/sunrise/calcdetails.html
-   It is based on equations from "Astronomical Algorithms" by
-   Jean Meeus. */
+ * National Oceanic & Atmospheric Administration:
+ * http://www.srrb.noaa.gov/highlights/sunrise/calcdetails.html
+ * It is based on equations from "Astronomical Algorithms" by
+ * Jean Meeus. */
 
 #include "common.h"
 #include "solar.h"
@@ -313,7 +313,7 @@ solar_table_fill(double date, double lat, double lon, double *table)
 	/* Calculate solar midnight */
 	table[SOLAR_TIME_MIDNIGHT] = epoch_from_jd(j_noon + 0.5);
 
-	/* Calulate absoute time of other phenomena */
+	/* Calulate absolute time of other phenomena */
 	for (int i = 2; i < SOLAR_TIME_MAX; i++) {
 		double angle = time_angle[i];
 		double offset = time_of_solar_elevation(t, t_noon, lat, lon, angle);
diff --git a/src/solar.h b/src/solar.h
index 2dba4d4..39ed9b5 100644
--- a/src/solar.h
+++ b/src/solar.h
@@ -1,22 +1,21 @@
 /* solar.h -- Solar position header
-   This file is part of redshift-ng.
-
-   redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
-
-   Copyright (c) 2010  Jon Lund Steffensen <jonlst@gmail.com>
-*/
-
+ * This file is part of redshift-ng.
+ * 
+ * redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * Copyright (c) 2010  Jon Lund Steffensen <jonlst@gmail.com>
+ */
 #ifndef REDSHIFT_SOLAR_H
 #define REDSHIFT_SOLAR_H
 
diff --git a/src/systemtime.c b/src/systemtime.c
index ac6d6e3..8ca845c 100644
--- a/src/systemtime.c
+++ b/src/systemtime.c
@@ -1,58 +1,52 @@
 /* systemtime.c -- Portable system time source
-   This file is part of redshift-ng.
-
-   redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
-
-   Copyright (c) 2010-2014  Jon Lund Steffensen <jonlst@gmail.com>
-*/
+ * This file is part of redshift-ng.
+ * 
+ * redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * Copyright (c) 2010-2014  Jon Lund Steffensen <jonlst@gmail.com>
+ * Copyright (c) 2025       Mattias Andrée <m@maandree.se>
+ */
 #include "common.h"
 
 
-/* Return current time in T as the number of seconds since the epoch. */
-int
-systemtime_get_time(double *t)
+double
+systemtime_get_time(void)
 {
-#if defined(WINDOWS) /* Windows */
+#if defined(WINDOWS)
 	FILETIME now;
 	ULARGE_INTEGER i;
 	GetSystemTimeAsFileTime(&now);
 	i.LowPart = now.dwLowDateTime;
 	i.HighPart = now.dwHighDateTime;
 	/* FILETIME is tenths of microseconds since 1601-01-01 UTC */
-	*t = (i.QuadPart / 10000000.0) - 11644473600.0;
+	return (i.QuadPart / 10000000.0) - 11644473600.0;
 
-#elif defined(_POSIX_TIMERS) /* POSIX timers */
+#elif defined(_POSIX_TIMERS)
 	struct timespec now;
-	if (clock_gettime(CLOCK_REALTIME, &now)) {
-		weprintf("clock_gettime CLOCK_REALTIME:");
-		return -1;
-	}
-	*t = now.tv_sec + (now.tv_nsec / 1000000000.0);
+	if (clock_gettime(CLOCK_REALTIME, &now))
+		eprintf("clock_gettime CLOCK_REALTIME:");
+	return now.tv_sec + (now.tv_nsec / 1000000000.0);
 
-#else /* other platforms */
+#else
 	struct timeval now;
-	if (gettimeofday(&now, NULL)) {
-		weprintf("gettimeofday:");
-		return -1;
-	}
-	*t = now.tv_sec + (now.tv_usec / 1000000.0);
+	if (gettimeofday(&now, NULL))
+		eprintf("gettimeofday:");
+	return = now.tv_sec + (now.tv_usec / 1000000.0);
 #endif
-
-	return 0;
 }
 
-/* Sleep for a number of milliseconds. */
+
 void
 systemtime_msleep(unsigned int msecs)
 {