add PID file handling to clients (including signal handling to remove the files)

clients/lcdexec/Makefile.am

@@ -8,7 +8,7 @@ lcdexec_SOURCES = lcdexec.c menu.c menu.h
 
 lcdexec_LDADD = ../../shared/libLCDstuff.a
 
-AM_CPPFLAGS = -I$(top_srcdir) -DSYSCONFDIR=\"$(sysconfdir)\"
+AM_CPPFLAGS = -I$(top_srcdir) -DSYSCONFDIR=\"$(sysconfdir)\" -DPIDFILEDIR=\"$(pidfiledir)\"
 
 
 EXTRA_DIST = $(sysconf_DATA)

clients/lcdexec/lcdexec.c

@@ -14,6 +14,7 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <string.h>
+#include <errno.h>
 #include <sys/utsname.h>
 #include <signal.h>
 #include <time.h>
@@ -32,8 +33,12 @@
 #if !defined(SYSCONFDIR)
 # define SYSCONFDIR	"/etc"
 #endif
+#if !defined(PIDFILEDIR)
+# define PIDFILEDIR	"/var/run"
+#endif
 
 #define DEFAULT_CONFIGFILE	SYSCONFDIR "/lcdexec.conf"
+#define DEFAULT_PIDFILE		PIDFILEDIR "/lcdexec.pid"
 
 
 /** information about a process started by lcdexec */
@@ -52,7 +57,7 @@ typedef struct ProcInfo {
 char * help_text =
 "lcdexec - LCDproc client to execute commands from the LCDd menu\n"
 "\n"
-"Copyright (c) 2002, Joris Robijn, 2006 Peter Marschall.\n"
+"Copyright (c) 2002, Joris Robijn, 2006,7 Peter Marschall.\n"
 "This program is released under the terms of the GNU General Public License.\n"
 "\n"
 "Usage: lcdexec [<options>]\n"
@@ -76,10 +81,11 @@ int port = UNSET_INT;
 int foreground = FALSE;
 static int report_level = UNSET_INT;
 static int report_dest = UNSET_INT;
+char *pidfile = NULL;
 char *displayname = NULL;
 char *default_shell = NULL;
 
-/* Other variables */
+/* Other global variables */
 MenuEntry *main_menu = NULL;	/**< pointer to the main menu */
 ProcInfo *proc_queue = NULL;	/**< pointer to the list of executed processes */
 
@@ -88,9 +94,12 @@ int lcd_hgt = 0;		/**< LCD display height reported by the server */
 
 int sock = -1;			/**< socket to connect to server */
 
+int Quit = 0;			/**< indicate end of main loop */
+
 
 /* Function prototypes */
-static void sigchld_handler(int);
+static void exit_program(int val);
+static void sigchld_handler(int signal);
 static int process_command_line(int argc, char **argv);
 static int process_configfile(char * configfile);
 static int connect_and_setup(void);
@@ -128,8 +137,30 @@ int main(int argc, char **argv)
 		if (daemon(1,1) != 0) {
 			report(RPT_ERR, "Error: daemonize failed");
 		}
+
+		if (pidfile != NULL) {
+			FILE *pidf = fopen(pidfile, "w");
+
+			if (pidf) {
+				fprintf(pidf, "%d\n", (int) getpid());
+				fclose(pidf);
+			} else {
+				fprintf(stderr, "Error creating pidfile %s: %s\n",
+					pidfile, strerror(errno));
+				return(EXIT_FAILURE);
+			}
+		}
 	}
 
+	/* setup signal handlers for common signals */
+	sigemptyset(&sa.sa_mask);
+	sa.sa_flags = SA_RESTART;
+	sa.sa_handler = exit_program;
+	sigaction(SIGINT, &sa, NULL);	// Ctrl-C
+	sigaction(SIGTERM, &sa, NULL);	// "regular" kill
+	sigaction(SIGHUP, &sa, NULL);	// kill -HUP
+	sigaction(SIGKILL, &sa, NULL);	// kill -9 [cannot be trapped; but ...]
+
 	/* setup signal handler for children to avoid zombies */
 	sigemptyset(&sa.sa_mask);
 	sa.sa_flags = SA_RESTART | SA_NOCLDSTOP;
@@ -138,7 +169,18 @@ int main(int argc, char **argv)
 
 	main_loop();
 
-	return 0;
+	exit_program(EXIT_SUCCESS);
+}
+
+
+static void exit_program(int val)
+{
+	//printf("exit program\n");
+	Quit = 1;
+	sock_close(sock);
+	if ((foreground != TRUE) && (pidfile != NULL))
+		unlink(pidfile);
+	exit(val);
 }
 
 
@@ -215,7 +257,7 @@ static int process_command_line(int argc, char **argv)
 			break;
 		  case 'h':
 			fprintf(stderr, "%s", help_text);
-			exit(0);
+			exit(EXIT_SUCCESS);
 		  case ':':
 			report(RPT_ERR, "Missing option argument for %c", optopt);
 			error = -1;
@@ -259,6 +301,9 @@ static int process_configfile(char *configfile)
 	if (foreground != TRUE) {
 		foreground = config_get_bool(progname, "Foreground", 0, FALSE);
 	}
+	if (pidfile == NULL) {
+		pidfile = strdup(config_get_string(progname, "PidFile", 0, DEFAULT_PIDFILE));
+	}
 
 	if ((tmp = config_get_string(progname, "DisplayName", 0, NULL)) != NULL)
 		displayname = strdup(tmp);
@@ -453,8 +498,7 @@ static int process_response(char *str)
 	else if (strcmp(argv[0], "bye") == 0) {
 		// TODO: make it better
 		report(RPT_INFO, "Server said: \"%s\"", str);
-		sock_close(sock);
+		exit_program(EXIT_SUCCESS);
-		exit(EXIT_SUCCESS);
 	}	
 	else if (strcmp(argv[0], "huh?") == 0) {
 		/* Report errors */
@@ -535,7 +579,7 @@ static int exec_command(MenuEntry *cmd)
 		  case 0:
 			/* We're the child: execute the command */
 			execve(argv[0], (char **) argv, envp);
-			exit(0);
+			exit(EXIT_SUCCESS);
 			break;
 		  default:
 			/* We're the parent: setup the ProcInfo structure */
@@ -644,7 +688,7 @@ static int main_loop(void)
 	int status_delay = 0;
 
 	/* Continuously check if we get a menu event... */
-	while ((num_bytes = sock_recv_string(sock, buf, sizeof(buf)-1)) >= 0) {
+	while (!Quit && ((num_bytes = sock_recv_string(sock, buf, sizeof(buf)-1)) >= 0)) {
 		if (num_bytes == 0) {
 			ProcInfo *p;
 
@@ -690,7 +734,8 @@ static int main_loop(void)
 		}
 	}
 
-	report(RPT_ERR, "Server disconnected (or connection error)");
+	if (!Quit)
+		report(RPT_ERR, "Server disconnected (or connection error)");
 	return 0;
 }
 

clients/lcdexec/lcdexec.conf

@@ -17,6 +17,9 @@ ReportToSyslog=false
 # run in foreground [default: false; legal: true, false]
 Foreground=false
 
+# PidFile location when running as daemon [default: /var/run/lcdexec.pid]
+#PidFile=/var/run/lcdexec.pid
+
 # shell to use for executing programsi
 # [default: $SHELL or /bin/sh; legal: any shell that understands: -c COMMAND]
 #Shell=/bin/sh

clients/lcdproc/Makefile.am

@@ -12,7 +12,7 @@ if DARWIN
 AM_LDFLAGS = -framework CoreFoundation -framework IOKit
 endif
 
-AM_CPPFLAGS = -I$(top_srcdir) -DSYSCONFDIR=\"$(sysconfdir)\"
+AM_CPPFLAGS = -I$(top_srcdir) -DSYSCONFDIR=\"$(sysconfdir)\" -DPIDFILEDIR=\"$(pidfiledir)\"
 
 
 EXTRA_DIST = $(sysconf_DATA)

clients/lcdproc/lcdproc.conf

@@ -17,6 +17,9 @@ ReportToSyslog=false
 # run in foreground [default: false; legal: true, false]
 #Foreground=true
 
+# PidFile location when running as daemon [default: /var/run/lcdproc.pid]
+#PidFile=/var/run/lcdproc.pid
+
 # slow down initial announcement of modes (in 1/100s)
 #delay=2
 

clients/lcdproc/main.c

@@ -70,11 +70,15 @@ static int process_configfile(char *cfgfile);
 #if !defined(SYSCONFDIR)
 # define SYSCONFDIR	"/etc"
 #endif
+#if !defined(PIDFILEDIR)
+# define PIDFILEDIR	"/var/run"
+#endif
 
 #define UNSET_INT		-1
 #define UNSET_STR		"\01"
 #define DEFAULT_SERVER		"127.0.0.1"
 #define DEFAULT_CONFIGFILE	SYSCONFDIR "/lcdproc.conf"
+#define DEFAULT_PIDFILE		PIDFILEDIR "/lcdproc.pid"
 #define DEFAULT_REPORTDEST	RPT_DEST_STDERR
 #define DEFAULT_REPORTLEVEL	RPT_WARNING
 
@@ -111,6 +115,7 @@ int port	= LCDPORT;
 int foreground 	= FALSE;
 static int report_level = UNSET_INT;
 static int report_dest 	= UNSET_INT;
+char *pidfile = NULL;
 char *configfile = NULL;
 char *displayname = NULL;
 
@@ -243,7 +248,7 @@ main(int argc, char **argv)
 	/* Read config file*/
 	cfgresult = process_configfile(configfile);
 	if (cfgresult < 0) {
-		fprintf(stderr, "Error reading config file");
+		fprintf(stderr, "Error reading config file\n");
 		exit(EXIT_FAILURE);
 	}	
 
@@ -303,9 +308,22 @@ main(int argc, char **argv)
 
 	if (foreground != TRUE) {
 		if (daemon(1,0) != 0) {
-			fprintf(stderr, "Error: daemonize failed");
+			fprintf(stderr, "Error: daemonize failed\n");
 			return(EXIT_FAILURE);
 		}
+
+		if (pidfile != NULL) {
+			FILE *pidf = fopen(pidfile, "w");
+
+			if (pidf) {
+				fprintf(pidf, "%d\n", (int) getpid());
+				fclose(pidf);
+			} else {
+				fprintf(stderr, "Error creating pidfile %s: %s\n",
+					pidfile, strerror(errno));
+				return(EXIT_FAILURE);
+			}
+		}
 	}	
 
 	// Init the status gatherers...
@@ -314,10 +332,8 @@ main(int argc, char **argv)
 	// And spew stuff!
 	main_loop();
 
-	// Clean up
+	// Clean up & exit
 	exit_program(EXIT_SUCCESS);
-
-	return(0);
 }
 
 
@@ -372,6 +388,9 @@ process_configfile(char *configfile)
 	if (foreground != TRUE) {
 		foreground = config_get_bool(progname, "Foreground", 0, FALSE);
 	}
+	if (pidfile == NULL) {
+		pidfile = strdup(config_get_string(progname, "PidFile", 0, DEFAULT_PIDFILE));
+	}
 	if (islow < 0) {
 		islow = config_get_int(progname, "Delay", 0, -1);
 	}
@@ -455,6 +474,8 @@ exit_program(int val)
 	Quit = 1;
 	sock_close(sock);
 	mode_close();
+	if ((foreground != TRUE) && (pidfile != NULL))
+		unlink(pidfile);
 	exit(val);
 }
 

clients/lcdvc/Makefile.am

@@ -12,7 +12,7 @@ if DARWIN
 AM_LDFLAGS = -framework CoreFoundation -framework IOKit
 endif
 
-AM_CPPFLAGS = -I$(top_srcdir) -DSYSCONFDIR=\"$(sysconfdir)\"
+AM_CPPFLAGS = -I$(top_srcdir) -DSYSCONFDIR=\"$(sysconfdir)\" -DPIDFILEDIR=\"$(pidfiledir)\"
 
 #AM_CFLAGS = -g -O0
 #AM_LDFLAGS = -g

clients/lcdvc/lcd_link.c

@@ -33,7 +33,7 @@ static int read_connect_string(void);
 static int split(char *str, char delim, char *parts[], int maxparts);
 
 
-int connect_and_setup(void)
+int setup_connection(void)
 {
 	char buf[200];
 	int i;
@@ -83,6 +83,14 @@ int connect_and_setup(void)
 }
 
 
+int teardown_connection(void)
+{
+	sock_close(sock);
+
+	return 0;
+}
+
+
 static int read_connect_string(void)
 {
 	char buf[8192];

clients/lcdvc/lcd_link.h

@@ -4,7 +4,8 @@
 extern char *address;
 extern int port;
 
-int connect_and_setup(void);
+int setup_connection(void);
+int teardown_connection(void);
 int read_response(char *str, int maxsize);
 int process_response(char *str);
 int update_display(void);

clients/lcdvc/lcdvc.c

@@ -14,6 +14,7 @@
 #include <string.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <signal.h>
 #include <fcntl.h>
 #include <errno.h>
 
@@ -30,8 +31,12 @@
 #if !defined(SYSCONFDIR)
 # define SYSCONFDIR	"/etc"
 #endif
+#if !defined(PIDFILEDIR)
+# define PIDFILEDIR	"/var/run"
+#endif
 
 #define DEFAULT_CONFIGFILE	SYSCONFDIR "/lcdvc.conf"
+#define DEFAULT_PIDFILE		PIDFILEDIR "/lcdvc.pid"
 
 
 char *help_text =
@@ -50,9 +55,6 @@ char *help_text =
 "    -s <0|1>            Report to syslog (1) or stderr (0, default)\n"
 "    -h                  Show this help\n";
 
-char *progname = "lcdvc";
-char *configfile = UNSET_STR;
-
 /* Variables set by config */
 int foreground = FALSE;
 static int report_level = UNSET_INT;
@@ -61,7 +63,15 @@ char *vcsa_device = UNSET_STR;
 char *vcs_device = UNSET_STR;
 char *keys[4];
 
+/* Other global variables */
+char *progname = "lcdvc";
+char *pidfile = NULL;
+char *configfile = UNSET_STR;
+
+int Quit = 0;			/**< indicate end of main loop */
+
 /* Function prototypes */
+static void exit_program(int val);
 static int process_command_line(int argc, char **argv);
 static int process_configfile(char *configfile);
 static int main_loop(void);
@@ -70,6 +80,7 @@ static int main_loop(void);
 int main(int argc, char **argv)
 {
 	int e = 0;
+	struct sigaction sa;
 
 	CHAIN( e, process_command_line( argc, argv ));
 	if (strcmp( configfile, UNSET_STR ) == 0) {
@@ -83,18 +94,51 @@ int main(int argc, char **argv)
 	set_reporting( progname, report_level, report_dest );
 
 	CHAIN( e, open_vcs() );
-	CHAIN( e, connect_and_setup() );
+	CHAIN( e, setup_connection() );
 	CHAIN_END( e );
 
 	if (foreground != TRUE) {
 		if (daemon(1,1) != 0) {
 			report(RPT_ERR, "Error: daemonize failed");
 		}
+
+		if (pidfile != NULL) {
+			FILE *pidf = fopen(pidfile, "w");
+
+			if (pidf) {
+				fprintf(pidf, "%d\n", (int) getpid());
+				fclose(pidf);
+			} else {
+				fprintf(stderr, "Error creating pidfile %s: %s\n",
+					pidfile, strerror(errno));
+				return(EXIT_FAILURE);
+			}
+		}
 	}
 
+	/* setup signal handlers for common signals */
+	sigemptyset(&sa.sa_mask);
+	sa.sa_flags = SA_RESTART;
+	sa.sa_handler = exit_program;
+	sigaction(SIGINT, &sa, NULL);	// Ctrl-C
+	sigaction(SIGTERM, &sa, NULL);	// "regular" kill
+	sigaction(SIGHUP, &sa, NULL);	// kill -HUP
+	sigaction(SIGKILL, &sa, NULL);	// kill -9 [cannot be trapped; but ...]
+
 	main_loop();
 
-	return 0;
+	exit_program(EXIT_SUCCESS);
+}
+
+
+static void exit_program(int val)
+{
+	//printf("exit program\n");
+	Quit = 1;
+	teardown_connection();
+	if ((foreground != TRUE) && (pidfile != NULL))
+		unlink(pidfile);
+	exit(val);
 }
 
 
@@ -113,7 +157,7 @@ static int process_command_line(int argc, char **argv)
 		switch (c) {
 		  case 'h':
 			fprintf(stderr, "%s", help_text);
-			exit( 0 );
+			exit(EXIT_SUCCESS);
 		  case 'c':
 			configfile = strdup(optarg);
 			break;
@@ -194,6 +238,10 @@ static int process_configfile(char *configfile)
 	if (foreground != TRUE) {
 		foreground = config_get_bool(progname, "Foreground", 0, FALSE);
 	}
+	if (pidfile == NULL) {
+		pidfile = strdup(config_get_string(progname, "PidFile", 0, DEFAULT_PIDFILE));
+	}
+
 	vcs_device = strdup(config_get_string(progname, "vcsDevice", 0, "/dev/vcs"));
 	vcsa_device = strdup(config_get_string(progname, "vcsaDevice", 0, "/dev/vcsa"));
 
@@ -214,7 +262,7 @@ static int main_loop(void)
 
 	/* Continuously check if we get a menu event... */
 
-	while ((num_bytes = read_response(buf, sizeof(buf)-1)) >= 0) {
+	while (!Quit && ((num_bytes = read_response(buf, sizeof(buf)-1)) >= 0)) {
 		if (num_bytes != 0) {
 			process_response(buf);
 		}
@@ -233,7 +281,8 @@ static int main_loop(void)
 		}
 	}
 
-	report(RPT_WARNING, "Server disconnected %d", num_bytes);
+	if (!Quit)
+		report(RPT_WARNING, "Server disconnected %d", num_bytes);
 	return 0;
 }
 

clients/lcdvc/lcdvc.conf

@@ -18,6 +18,9 @@
 # run in foreground [default: false; legal: true, false]
 #Foreground=false
 
+# PidFile location when running as daemon [default: /var/run/lcdvc.pid]
+#PidFile=/var/run/lcdvc.pid
+
 # Keys to move the visible area around the screen.
 #UpKey=Up
 #DownKey=Down

configure.in

@@ -273,6 +273,30 @@ dnl Select drivers to build
 LCD_DRIVERS_SELECT
 
 
+# directory for PID files
+pidfiledir=/var/run
+# make sure the directory exists
+if test ! -d $pidfiledir ; then
+        pidfiledir=`eval echo ${sysconfdir}`
+	case $pidfiledir in
+		NONE/*) pidfiledir=`echo $pidfiledir | sed "s~NONE~$ac_default_prefix~"` ;;
+	esac
+fi
+		
+AC_ARG_WITH(pidfile-dir,
+	[AS_HELP_STRING([--with-pidfile-dir=PATH], [specify location of pid files [/var/run]])],
+	[ if test -n "$withval"  &&  test "x$withval" != "xno"  &&  \
+	     test "x${withval}" != "xyes"; then
+		pidfiledir=$withval
+		if test ! -d $pidfiledir ; then
+			AC_MSG_WARN([** no $pidfiledir directory on this system **])
+		fi
+	fi ]
+)
+
+AC_SUBST(pidfiledir)
+
+
 # Features applicable to the server
 AC_ARG_ENABLE(seamless-hbars,
 	[AS_HELP_STRING([--enable-seamless-hbars], [no gaps in horizontal bar graphs (if HW supports it)])],