Major refactoring and some fixes

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

1 files changed, 232 insertions, 0 deletions

diff --git a/src/util.c b/src/util.c
new file mode 100644
index 0000000..fc6dc2c
--- /dev/null
+++ b/src/util.c
@@ -0,0 +1,232 @@
+/* redshift-ng - Automatically adjust display colour temperature according the Sun
+ * 
+ * Copyright (c) 2009-2018        Jon Lund Steffensen <jonlst@gmail.com>
+ * Copyright (c) 2014-2016, 2025  Mattias Andrée <m@maandree.se>
+ * 
+ * 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/>.
+ */
+#include "common.h"
+
+
+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;
+}
+
+
+char *
+ltrim(char *s)
+{
+	while (*s == ' ' || *s == '\t')
+		s++;
+	return s;
+}
+
+
+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 in some manner
+ * 
+ * @param   path_spec    Specification for the path to try
+ * @param   path_out     Output parameter for the found file
+ * @param   pathbuf_out  Output parameter for the memory allocation for `*path_out`;
+ *                       shall be free(3)d by the caller
+ * @param   open_cb      Pointer to function used to open the file, unless it
+ *                       returns `NULL` it's return value is returned by the
+ *                       function (`try_path`); `NULL` shall be returned if the
+ *                       file `path` does not exist
+ * @return               File access object to the found file; `NULL` if not found
+ */
+static void *
+try_path(const struct env_path *path_spec, const char **path_out, char **pathbuf_out, void *(*open_cb)(const char *path))
+{
+	const char *prefix, *p, *q;
+	char *path;
+	size_t len;
+	void *f = NULL;
+
+	*path_out = NULL;
+	*pathbuf_out = NULL;
+
+	if (!path_spec->prefix_env) {
+		prefix = get_home();
+	} else if (*path_spec->prefix_env) {
+		prefix = getenv(path_spec->prefix_env);
+	} else {
+		f = (*open_cb)(path_spec->suffix);
+		if (f)
+			*path_out = path_spec->suffix;
+		return f;
+	}
+	if (!prefix || !*prefix)
+		return NULL;
+
+	path = emalloc(strlen(prefix) + strlen(path_spec->suffix) + 1U);
+
+	if (path_spec->multidir_env) {
+		for (p = prefix; !f && *p; p = &q[!!*q]) {
+#ifdef strchrnul
+			q = strchrnul(p, PATH_DELIMITER);
+#else
+			q = strchr(p, PATH_DELIMITER);
+			q = q ? q : strchr(p, '\0');
+#endif
+			len = (size_t)(q - p);
+			if (!len)
+				continue;
+
+			memcpy(path, p, len);
+			stpcpy(&path[len], path_spec->suffix);
+			f = (*open_cb)(path);
+		}
+	} else {
+		stpcpy(stpcpy(path, prefix), path_spec->suffix);
+		f = (*open_cb)(path);
+	}
+
+	if (f)
+		*path_out = *pathbuf_out = path;
+	else
+		free(path);
+	return f;	
+}
+
+
+/**
+ * Open a file for reading, if it exists
+ * 
+ * @param   path  The path to the file
+ * @return        `FILE` object for reading the file,
+ *                `NULL` if it doesn't exist
+ */
+static void *
+open_file(const char *path)
+{
+	FILE *f = fopen(path, "r");
+	if (!f && errno != ENOENT)
+		eprintf("fopen %s \"r\":", path);
+	return f;
+}
+
+
+FILE *
+try_path_fopen(const struct env_path *path_spec, const char **path_out, char **pathbuf_out)
+{
+	return try_path(path_spec, path_out, pathbuf_out, &open_file);
+}
+
+
+/**
+ * Open a directory for reading, if it exists
+ * 
+ * @param   path  The path to the directory
+ * @return        `DIR` object for reading the directory,
+ *                `NULL` if it doesn't exist
+ */
+static void *
+open_dir(const char *path)
+{
+	DIR *f = opendir(path);
+	if (!f && errno != ENOENT)
+		eprintf("opendir %s:", path);
+	return f;
+}
+
+
+DIR *
+try_path_opendir(const struct env_path *path_spec, const char **path_out, char **pathbuf_out)
+{
+	return try_path(path_spec, path_out, pathbuf_out, &open_dir);
+}
+
+
+int
+pipe_nonblock(int pipefds[2])
+{
+#ifdef WINDOWS
+	(void) pipefds;
+	return -1;
+#else
+
+	int i, flags;
+
+# if defined(__linux__) && !defined(MISSING_PIPE2)
+	if (!pipe2(pipefds, O_NONBLOCK)) {
+		return 0;
+	} else if (errno != ENOSYS) {
+		weprintf("pipe2 <buffer> O_NONBLOCK:");
+		return -1;
+	}
+# endif
+
+	if (pipe(pipefds)) {
+		weprintf("pipe:");
+		return -1;
+	}
+
+	for (i = 0; i < 2; i++) {
+		flags = fcntl(pipefds[0], F_GETFL);
+		if (flags == -1) {
+			weprintf("fcntl <pipe> F_GETFL:");
+			goto fail;
+		}
+		if (fcntl(pipefds[0], F_SETFL, flags | O_NONBLOCK)) {
+			weprintf("fcntl <pipe> F_SETFL +O_NONBLOCK:");
+			goto fail;
+		}
+	}
+
+	return 0;
+
+fail:
+	close(pipefds[0]);
+	close(pipefds[1]);
+	return -1;
+#endif
+}