#include <sys/types.h> /* getgrnam() */
#include <grp.h>
#include <signal.h>
+#include <sys/resource.h>
#include "para.h"
#include "daemon.h"
color_parse_or_die(default_log_colors[i], me->log_colors[i]);
}
-/*
+/**
* Set the color for one loglevel.
*
- * arg must be of the form "ll:[fg [bg]] [attr]".
+ * \param arg Must be of the form "ll:[fg [bg]] [attr]".
*/
-static void daemon_set_log_color_or_die(char const *arg)
+void daemon_set_log_color_or_die(const char *arg)
{
char *p = strchr(arg, ':');
int ret, ll;
color_parse_or_die(p, me->log_colors[ll]);
return;
err:
- PARA_EMERG_LOG("%s: color syntax error\n", arg);
+ PARA_EMERG_LOG("%s: invalid color argument\n", arg);
exit(EXIT_FAILURE);
}
* \param color_arg_auto The value for automatic color detection.
* \param color_arg_no The value to disable colored log messages.
* \param logfile_given In auto mode colors are disabled if this value is true.
- * \param log_color_argv Color specifiers given to --log-color.
- * \param argc Number of color specifiers in \a log_color_argv.
*
- * If \a color_arg equals \a color_arg_no, color mode is disabled, i.e., calls
- * to \a para_log() will not produce colored output. If \a color_arg == \a
- * color_arg_auto, the function autodetects whether to activate colors.
- * Otherwise color mode is enabled.
+ * If color_arg equals color_arg_no, color mode is disabled. That is, calls to
+ * para_log() will not produce colored output. If color_arg equals
+ * color_arg_auto, the function detects automatically whether to activate
+ * colors. Otherwise color mode is enabled.
+ *
+ * If color mode is to be enabled, the default colors are set for each
+ * loglevel. They can be overwritten by calling daemon_set_log_color_or_die().
*
- * If color mode is to be enabled, the strings in \a log_color_argv are parsed
- * and the color scheme is updated accordingly. For each loglevel, the default
- * colors apply if there is no log_color_argv for this loglevel.
+ * \return Whether colors have been enabled by the function.
*/
-void daemon_init_colors_or_die(int color_arg, int color_arg_auto,
- int color_arg_no, bool logfile_given, char **log_color_argv,
- int argc)
+bool daemon_init_colors_or_die(int color_arg, int color_arg_auto,
+ int color_arg_no, bool logfile_given)
{
- int i;
-
if (color_arg == color_arg_no)
- return;
+ return false;
if (color_arg == color_arg_auto) {
if (logfile_given)
- return;
+ return false;
if (!isatty(STDERR_FILENO))
- return;
+ return false;
}
daemon_set_flag(DF_COLOR_LOG);
daemon_set_default_log_colors();
- for (i = 0; i < argc; i++)
- daemon_set_log_color_or_die(log_color_argv[i]);
+ return true;
}
/**
*
* \param logfile_name The full path of the logfile.
*/
-void daemon_set_logfile(char *logfile_name)
+void daemon_set_logfile(const char *logfile_name)
{
free(me->logfile_name);
me->logfile_name = NULL;
*
* \param loglevel The smallest level that should be logged.
*/
-void daemon_set_loglevel(char *loglevel)
+void daemon_set_loglevel(const char *loglevel)
{
int ret = get_loglevel_by_name(loglevel);
return me->flags & flag;
}
-static void dummy_sighandler(__a_unused int s)
-{
-}
-
/**
* Do the usual stuff to become a daemon.
*
*
* Fork, become session leader, cd to /, and dup fd 0, 1, 2 to /dev/null. If \a
* parent_waits is false, the parent process terminates immediately.
- * Otherwise, it calls pause() to sleep until it receives \p SIGTERM or \p
- * SIGCHLD and exits successfully thereafter. This behaviour is useful if the
- * daemon process should not detach from the console until the child process
- * has completed its setup.
+ * Otherwise, a pipe is created prior to the fork() and the parent tries to
+ * read a single byte from the reading end of the pipe. The child is supposed
+ * to write to the writing end of the pipe after it completed its setup
+ * procedure successfully. This behaviour is useful to let the parent process
+ * die with an error if the child process aborts early, since in this case the
+ * read() will return non-positive.
+ *
+ * \return This function either succeeds or calls exit(3). If parent_waits is
+ * true, the return value is the file descriptor of the writing end of the
+ * pipe. Otherwise the function returns zero.
*
* \sa fork(2), setsid(2), dup(2), pause(2).
*/
-void daemonize(bool parent_waits)
+int daemonize(bool parent_waits)
{
pid_t pid;
- int null;
+ int null, pipe_fd[2];
- PARA_INFO_LOG("daemonizing\n");
+ if (parent_waits && pipe(pipe_fd) < 0)
+ goto err;
+ PARA_INFO_LOG("subsequent log messages go to %s\n", me->logfile_name?
+ me->logfile_name : "/dev/null");
pid = fork();
if (pid < 0)
goto err;
- if (pid) {
+ if (pid) { /* parent exits */
if (parent_waits) {
- signal(SIGTERM, dummy_sighandler);
- signal(SIGCHLD, dummy_sighandler);
- pause();
+ char c;
+ close(pipe_fd[1]);
+ exit(read(pipe_fd[0], &c, 1) <= 0?
+ EXIT_FAILURE : EXIT_SUCCESS);
}
- exit(EXIT_SUCCESS); /* parent exits */
+ exit(EXIT_SUCCESS);
}
+ if (parent_waits)
+ close(pipe_fd[0]);
/* become session leader */
if (setsid() < 0)
goto err;
if (dup2(null, STDERR_FILENO) < 0)
goto err;
close(null);
- return;
+ return parent_waits? pipe_fd[1] : 0;
err:
PARA_EMERG_LOG("fatal: %s\n", strerror(errno));
exit(EXIT_FAILURE);
PARA_INFO_LOG("welcome to para_%s-" PACKAGE_VERSION " \n", name);
}
+/**
+ * Renice the calling process.
+ *
+ * \param prio The priority value to set.
+ *
+ * Errors are not considered fatal, but a warning message is logged if the
+ * underlying call to setpriority(2) fails.
+ */
+void daemon_set_priority(int prio)
+{
+ if (setpriority(PRIO_PROCESS, 0, prio) < 0)
+ PARA_WARNING_LOG("could not set priority to %d: %s\n", prio,
+ strerror(errno));
+}
+
/**
* Give up superuser privileges.
*
projects / paraslash.git / blobdiff