--- a/syslog_in_npipe.c	Wed Mar 29 08:45:17 2006 +0200
+++ b/syslog_in_npipe.c	Wed Mar 29 08:45:32 2006 +0200
@@ -7,6 +7,8 @@
 #include <sys/stat.h>  // Per crides de fitxer
 #include <fcntl.h>  // Per crides de fitxer
 #include <stdbool.h>  // Per les macros bool,true,false
+#include <unistd.h>  // Pel lockf()
+#include <fcntl.h>  // Pel lockf()
 
 #include "rfc3164.h"
 
@@ -36,11 +38,69 @@
 	return false;
 }
 
-int main(int argn, char **argv)
+int pipe_server(const char * restrict filename)
 {
 	int fd_entrada;
 	char missatge[MESSAGE_LENGTH];
 	int status;
+	struct flock blocking;
+
+	blocking.l_type = F_RDLCK;
+	blocking.l_whence = SEEK_SET;
+	blocking.l_start = 0;
+	blocking.l_len = 0;
+
+	while(true)
+	{
+		/* Obrim la named fifo síncrona. */
+		fd_entrada = open(filename, O_RDONLY);
+		if (fd_entrada < 0) {
+			printf("Error opening the named pipe: %s\n",
+				strerror(errno));
+			return 1;
+		}
+
+		status = fcntl(fd_entrada, F_SETLKW, &blocking);
+		if (fd_entrada < 0) {
+			printf("Error locking the named pipe: %s\n",
+				strerror(errno));
+			return 1;
+		}
+
+		while ((status = read(fd_entrada, missatge,
+			MESSAGE_LENGTH +1)) > 0)
+		{
+			process_message(missatge);
+		}
+
+		if (status < 0)
+		{
+			printf("Error reading the named pipe: %s\n",
+				strerror(errno));
+			blocking.l_type = F_UNLCK;
+			status = fcntl(fd_entrada, F_SETLKW, &blocking);
+			if (fd_entrada < 0) {
+				printf("Error unlocking the named pipe: %s\n",
+					strerror(errno));
+				abort();
+			}
+			close (fd_entrada);
+			return 1;
+		}
+	}
+
+	blocking.l_type = F_UNLCK;
+	status = fcntl(fd_entrada, F_SETLKW, &blocking);
+	if (fd_entrada < 0) {
+		printf("Error unlocking the named pipe: %s\n", strerror(errno));
+		abort();
+	}
+
+	close (fd_entrada);
+}
+
+int main(int argn, char **argv)
+{
 
 	/* Processem els paràmetres d'entrada */
 	if (argn != 2) {
@@ -56,30 +116,6 @@
 		abort();
 	};
 
-	/* Obrim la named fifo síncrona. */
-	fd_entrada = open(argv[1], O_RDONLY);
-	if (fd_entrada < 0) {
-		printf("Error opening the named pipe: %s\n",
-			strerror(errno));
-		return 1;
-	}
 
-	while ((status = read(fd_entrada, missatge, MESSAGE_LENGTH +1)) > 0)
-	{
-		/* Dummy */
-		printf(missatge);
-		printf("\n");
-	}
-
-	if (status < 0)
-	{
-		printf("Error reading the named pipe: %s\n",
-			strerror(errno));
-		close (fd_entrada);
-		return 1;
-	}
-
-	close (fd_entrada);
-
-	return 0;
+	return pipe_server(argv[1]);
 }