add support for executing external commands

close #1

6 files changed, 160 insertions, 24 deletions

diff --git a/Makefile b/Makefile
index b3b34ef..9230401 100644
--- a/Makefile
+++ b/Makefile
@@ -32,6 +32,8 @@ install-bin: journal-notify
 	$(INSTALL) -D -m0755 examples/journal-notify-crit-alert-emerg.desktop $(DESTDIR)/usr/share/journal-notify/examples/journal-notify-crit-alert-emerg.desktop
 	$(INSTALL) -D -m0755 examples/journal-notify-dhcpd.desktop $(DESTDIR)/usr/share/journal-notify/examples/journal-notify-dhcpd.desktop
 	$(INSTALL) -D -m0755 examples/journal-notify-sshd.desktop $(DESTDIR)/usr/share/journal-notify/examples/journal-notify-sshd.desktop
+	$(INSTALL) -D -m0755 execute/echo.sh $(DESTDIR)/usr/share/journal-notify/execute/echo.sh
+	$(INSTALL) -D -m0755 execute/mail.sh $(DESTDIR)/usr/share/journal-notify/execute/mail.sh
 
 install-doc: README.html
 	$(INSTALL) -D -m0644 README.md $(DESTDIR)/usr/share/doc/journal-notify/README.md
diff --git a/README.md b/README.md
index 3c4f4d1..52b97a7 100644
--- a/README.md
+++ b/README.md
@@ -61,16 +61,26 @@ Be warned: This can flood your disktop with notifications.
 * *-r REGEX*: This add a regular expression match for the message field.
 * *-t SECONDS*: seconds to show the notification, 0 is forever
 * *-v*: verbose output, can be specified multiple times
+* *-x EXECUTABLE*: execute EXECUTABLE
+* *-X EXECUTABLE*: execute EXECUTABLE, do not show notification
 
 The screenshot shown above resulted from this command:
 
 > journal-notify -m SYSLOG_IDENTIFIER=sshd -e -r "^(error:|Accepted)"
 -i security-high
 
+The command specified by `-x` is called with three options. Make sure
+your executable understands these options:
+
+* *-i*: syslog identifier
+* *-p*: priority
+* *-m*: message
+
 Additionally example desktop files are installed to
 `/usr/share/journal-notify/examples`. You should copy them to
 `~/.config/autostart/` to enable autostart or create your own desktop files
-there.
+there. Example execute scripts are installed to
+`/usr/share/journal-notify/execute/`.
 
 ### Upstream
 
diff --git a/execute/echo.sh b/execute/echo.sh
new file mode 100755
index 0000000..15ca215
--- /dev/null
+++ b/execute/echo.sh
@@ -0,0 +1,28 @@
+#!/bin/sh
+#
+# (C) 2015 by Christian Hesse <mail@eworm.de>
+#
+# This software may be used and distributed according to the terms
+# of the GNU General Public License, incorporated herein by reference.
+
+while getopts "i:p:m:" opt; do
+	case ${opt} in
+		i)
+			IDENTIFIER="${OPTARG}"
+			;;
+		p)
+			PRIORITY="${OPTARG}"
+			;;
+		m)
+			MESSAGE="${OPTARG}"
+			;;
+	esac
+done
+
+echo "IDENTIFIER: ${IDENTIFIER}"
+echo "PRIORITY:   ${PRIORITY}"
+echo "MESSAGE:    ${MESSAGE}"
+
+exit 0
+
+# vim: set syntax=sh:
diff --git a/execute/mail.sh b/execute/mail.sh
new file mode 100755
index 0000000..2d757db
--- /dev/null
+++ b/execute/mail.sh
@@ -0,0 +1,26 @@
+#!/bin/sh
+#
+# (C) 2015 by Christian Hesse <mail@eworm.de>
+#
+# This software may be used and distributed according to the terms
+# of the GNU General Public License, incorporated herein by reference.
+
+while getopts "i:p:m:" opt; do
+	case ${opt} in
+		i)
+			IDENTIFIER="${OPTARG}"
+			;;
+		p)
+			PRIORITY="${OPTARG}"
+			;;
+		m)
+			MESSAGE="${OPTARG}"
+			;;
+	esac
+done
+
+mail -s "[${PRIORITY}] ${IDENTIFIER}" mail@example.com <<< "${MESSAGE}"
+
+exit 0
+
+# vim: set syntax=sh:
diff --git a/journal-notify.c b/journal-notify.c
index 73af0f5..8f6e0b1 100644
--- a/journal-notify.c
+++ b/journal-notify.c
@@ -9,7 +9,7 @@
 
 const char * program = NULL;
 
-const static char optstring[] = "aehi:m:nor:t:v";
+const static char optstring[] = "aehi:m:nor:t:vx:X:";
 const static struct option options_long[] = {
 	/* name			has_arg			flag	val */
 	{ "and",		no_argument,		NULL,	'a' },
@@ -22,6 +22,8 @@ const static struct option options_long[] = {
 	{ "regex",		required_argument,	NULL,	'r' },
 	{ "timeout",		required_argument,	NULL,	't' },
 	{ "verbose",		no_argument,		NULL,	'v' },
+	{ "execute",		required_argument,	NULL, 	'x' },
+	{ "execute-only",	required_argument,	NULL, 	'X' },
 	{ 0, 0, 0, 0 }
 };
 
@@ -102,9 +104,15 @@ int main(int argc, char **argv) {
 
 	char * identifier, * message;
 	uint8_t priority;
-	const char * icon = DEFAULTICON;
+	const char * priorityname,
+	      * icon = DEFAULTICON;
 	int timeout = -1;
 
+	uint8_t executeonly = 0;
+	char * execute = NULL;
+	pid_t child_pid, wpid;
+	int status;
+
 	program = argv[0];
 
 	/* get command line options - part I
@@ -210,13 +218,23 @@ int main(int argc, char **argv) {
 					printf("Notifications will be displayed for %d seconds.\n", timeout);
 
 				break;
+			case 'X':
+				executeonly = 1;
+			case 'x':
+				execute = optarg;
+				if (verbose > 1)
+					printf("Command used for execution: %s\n", execute);
+
+				break;
 		}
 	}
 
-	if (notify_init(program) == FALSE) {
-		fprintf(stderr, "Failed to initialize notify.\n");
-		rc = EXIT_FAILURE;
-		goto out30;
+	if (executeonly == 0) {
+		if (notify_init(program) == FALSE) {
+			fprintf(stderr, "Failed to initialize notify.\n");
+			rc = EXIT_FAILURE;
+			goto out30;
+		}
 	}
 
 	while (1) {
@@ -266,29 +284,69 @@ int main(int argc, char **argv) {
 			continue;
 		}
 		priority = atoi(data + 9);
+		priorityname = priorities[priority];
 
 		if (verbose > 2)
 			printf("Received message from journal: %s\n", message);
 
-		/* show notification */
 		if (have_regex == 0 || regexec(&regex, message, 0, NULL, 0) == 0) {
-			for (i = 0; i < 3; i++) {
-				if (verbose > 0)
-					printf("Showing notification: %s: %s\n", identifier, message);
-
-				if ((rc = notify(identifier, message, priority, icon, timeout)) == 0)
-					break;
-
-				fprintf(stderr, "Failed to show notification, reinitializing libnotify.\n");
-				notify_uninit();
-				usleep(500 * 1000);
-				if (notify_init(program) == FALSE) {
-					fprintf(stderr, "Failed to initialize notify.\n");
-					rc = EXIT_FAILURE;
+			/* show notification */
+			if (executeonly == 0) {
+				for (i = 0; i < 3; i++) {
+					if (verbose > 0)
+						printf("Showing notification: %s: %s\n", identifier, message);
+
+					if ((rc = notify(identifier, message, priority, icon, timeout)) == 0)
+						break;
+
+					fprintf(stderr, "Failed to show notification, reinitializing libnotify.\n");
+					notify_uninit();
+					usleep(500 * 1000);
+					if (notify_init(program) == FALSE) {
+						fprintf(stderr, "Failed to initialize notify.\n");
+						rc = EXIT_FAILURE;
+					}
+				}
+				if (rc != 0)
+					goto out40;
+			}
+
+			/* execute command */
+			if (execute) {
+				if (verbose > 1)
+					printf("Executing: %s -i %s -p %s -m %s\n",
+						execute, identifier, priorityname, message);
+
+				if ((child_pid = fork()) < 0) {
+					fprintf(stderr, "fork() failed\n");
+				} else if (child_pid == 0) { /* This is the child */
+					rc = execlp(execute, execute, "-i", identifier,
+						"-p", priorityname, "-m", message, NULL);
+					/* execlp() should replace the process, so anything failed */
+					fprintf(stderr, "Failed to execute '%s': %s\n", execute, strerror(-rc));
+					goto out10;
+				} else { /* This is the parent */
+					do {
+						if ((wpid = waitpid(child_pid, &status, WUNTRACED|WCONTINUED)) < 0) {
+							perror("waitpid");
+							goto out40;
+						}
+
+						if (WIFEXITED(status)) {
+							if (WEXITSTATUS(status) > 0 || verbose > 1)
+								printf("child exited, status %d\n", WEXITSTATUS(status));
+						} else if (WIFSIGNALED(status)) {
+							printf("child killed (signal %d)\n", WTERMSIG(status));
+						} else if (WIFSTOPPED(status)) {
+							printf("child stopped (signal %d)\n", WSTOPSIG(status));
+						} else if (WIFCONTINUED(status)) {
+							printf("child continued\n");
+						} else {
+							printf("Unexpected status (0x%x)\n", status);
+						}
+					} while (!WIFEXITED(status) && !WIFSIGNALED(status));
 				}
 			}
-			if (rc != 0)
-				goto out40;
 		}
 
 		free(identifier);
@@ -298,7 +356,8 @@ int main(int argc, char **argv) {
 	rc = EXIT_SUCCESS;
 
 out40:
-	notify_uninit();
+	if (executeonly == 0)
+		notify_uninit();
 
 out30:
 	if (have_regex > 0)
diff --git a/journal-notify.h b/journal-notify.h
index ee18b7b..0dd2962 100644
--- a/journal-notify.h
+++ b/journal-notify.h
@@ -16,6 +16,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <sys/wait.h>
 
 #include <systemd/sd-journal.h>
 
@@ -25,6 +26,16 @@
 
 #define DEFAULTICON	"dialog-information"
 
+const char * priorities[] = {
+	"EMERG", /* 0 */
+	"ALERT",
+	"CRIT",
+	"ERR",
+	"WARNING",
+	"NOTICE",
+	"INFO",
+	"DEBUG" /* 7 */};
+
 /*** notify ***/
 int notify(const char * identifier, const char * message, uint8_t priority,
 		const char * icon, int timeout);