Sent to ceharris.

svn path=/trunk/; revision=10

6 files changed, 120 insertions, 4 deletions

diff --git a/README b/README
index c2894ba9..2445e7c2 100644
--- a/README
+++ b/README
@@ -1,6 +1,9 @@
 Popclient README
 
 	$Log: README,v $
+	Revision 1.3  1996/06/27 19:22:31  esr
+	Sent to ceharris.
+
 	Revision 1.2  1996/06/26 19:08:55  esr
 	This is what I sent Harris.
 
@@ -89,6 +92,10 @@ FUNCTIONAL ENHANCEMENTS
 
 * I have implemented daemon mode.
 
+* I have added a lock check to ensure that there is only one popclient
+  running per user, and a --quit option to kill the currently running
+  one.
+
 DOCUMENTATION
 
 * All changes and feature additions have been tested in actual use and are
diff --git a/daemon.c b/daemon.c
index cdfb35f9..0776d062 100644
--- a/daemon.c
+++ b/daemon.c
@@ -25,6 +25,9 @@
 		BSD systems.
 
   $Log: daemon.c,v $
+  Revision 1.3  1996/06/27 19:22:31  esr
+  Sent to ceharris.
+
   Revision 1.2  1996/06/26 19:08:57  esr
   This is what I sent Harris.
 
@@ -57,6 +60,7 @@
 
 #include "popclient.h"
 
+static void (*my_termhook)(void);
 
 /******************************************************************
   function:	sigchld_handler
@@ -80,6 +84,9 @@ sigchld_handler ()
   int status;
 #endif
 
+  if (my_termhook)
+      (*my_termhook)();
+
 #if 	defined(HAVE_WAIT3)
   while ((pid = wait3(&status, WNOHANG, (struct rusage *) 0)) > 0)
     ; /* swallow 'em up. */
@@ -109,8 +116,9 @@ sigchld_handler ()
  *****************************************************************/
 
 int
-daemonize (logfile)
+daemonize (logfile, termhook)
 const char *logfile;
+void (*termhook)(void);
 {
   int fd;
   pid_t childpid;
@@ -119,6 +127,8 @@ const char *logfile;
   /* if we are started by init (process 1) via /etc/inittab we needn't 
      bother to detach from our process group context */
 
+  my_termhook = termhook;
+
   if (getppid() == 1) 
     goto nottyDetach;
 
diff --git a/fetchmail.c b/fetchmail.c
index 10bff927..c85aec3a 100644
--- a/fetchmail.c
+++ b/fetchmail.c
@@ -22,6 +22,9 @@
   description:	main driver module for popclient
 
   $Log: fetchmail.c,v $
+  Revision 1.3  1996/06/27 19:22:32  esr
+  Sent to ceharris.
+
   Revision 1.2  1996/06/26 19:08:59  esr
   This is what I sent Harris.
 
@@ -113,6 +116,7 @@ int outlevel;		/* see the O_.* constants in popclient.h */
 /* Daemon-mode control */
 int poll_interval;	/* polling interval for daemon mode */
 char *logfile;		/* logfile to ship progress reports to */ 
+int quitmode;		/* if -quit was set */
 
 /* args for the MDA, parsed out in the usual fashion by parseMDAargs() */
 char *mda_argv [32];
@@ -130,6 +134,9 @@ char *mda_argv [32];
   globals:       none.
  *********************************************************************/
 
+static void termhook();
+static char *lockfile;
+
 main (argc,argv)
 int argc;
 char **argv;
@@ -140,6 +147,8 @@ char **argv;
   int parsestatus;
   char *servername; 
   struct hostrec *hostp, *hostlist = (struct hostrec *)NULL;
+  FILE	*tmpfp;
+  pid_t pid;
 
   if ((parsestatus = parsecmdline(argc,argv,&cmd_opts)) < 0)
     exit(PS_SYNTAX);
@@ -190,11 +199,66 @@ char **argv;
     exit(PS_SYNTAX);
   }
 
+  /* beyond here we don't want more than one popclient running per user */
+  umask(0077);
+  if ((lockfile = (char *) malloc( strlen(getenv("HOME")) + strlen("/.lockfetch-") + HOSTLEN)) == NULL) {
+    fprintf(stderr,"popclient: cannot allocate memory for .lockfetch, exiting.\n");
+    exit(PS_EXCLUDE);
+  }
+  strcpy(lockfile, getenv("HOME"));
+  strcat(lockfile,"/.lockfetch-");
+  gethostname(lockfile+strlen(lockfile),HOSTLEN);
+
+  /* check the lock, maybe remove it */
+  if (!quitmode)
+    {
+      /* check the lock */
+      if ( (tmpfp = fopen(lockfile, "r")) != NULL ) {
+	fscanf(tmpfp,"%d",&pid);
+	fprintf(stderr,"Another session appears to be running at pid %d.\nIf you are sure that this is incorrect, remove %s file.\n",pid,lockfile);
+	fclose(tmpfp);
+	return(PS_EXCLUDE);
+      }
+
+      /* if not locked, assert a lock */
+      else if ( (tmpfp = fopen(lockfile,"w")) != NULL ) {
+	signal(SIGABRT, termhook);
+	signal(SIGINT, termhook);
+	signal(SIGTERM, termhook);
+	signal(SIGALRM, termhook);
+	signal(SIGHUP, termhook);
+	signal(SIGPIPE, termhook);
+	signal(SIGQUIT, termhook);
+	fprintf(tmpfp,"%d",getpid());
+	fclose(tmpfp);
+      }
+    }
+  else
+    {
+      FILE* fp;
+
+      if ( (fp = fopen(lockfile, "r")) == NULL ) {
+	fprintf(stderr,"popclient: no other popclient is running\n");
+	return(PS_EXCLUDE);
+      }
+  
+      fscanf(fp,"%d",&pid);
+      fprintf(stderr,"popclient: killing popclient at PID %d\n",pid);
+      if ( kill(pid,SIGKILL) < 0 )
+	fprintf(stderr,"popclient: error killing the process %d\n.",pid);
+      else
+	fprintf(stderr,"popclient: popclient at %d is dead.\n", pid);
+  
+      fclose(fp);
+      remove(lockfile);
+      exit(0);
+    }
+
   /*
    * Maybe time to go to demon mode...
    */
   if (poll_interval)
-      daemonize(logfile);
+    daemonize(logfile, termhook);
 
   /*
    * Query all hosts. If there's only one, the error return will
@@ -209,9 +273,15 @@ char **argv;
   } while
       (poll_interval);
 
+  termhook();
   exit(popstatus);
 }
 
+void termhook()
+{
+    unlink(lockfile);
+}
+
 int query_host(servername, options)
 /* perform fetch transaction with single host */
 char *servername;
diff --git a/fetchmail.h b/fetchmail.h
index 814605ad..0e85fc8e 100644
--- a/fetchmail.h
+++ b/fetchmail.h
@@ -23,6 +23,9 @@
   description:  global constant, type, and variable definitions.
 
   $Log: fetchmail.h,v $
+  Revision 1.3  1996/06/27 19:22:33  esr
+  Sent to ceharris.
+
   Revision 1.2  1996/06/26 19:08:59  esr
   This is what I sent Harris.
 
@@ -85,6 +88,7 @@
 #define		PS_SYNTAX	5	/* command-line syntax error */
 #define		PS_IOERR	6	/* local folder I/O woes */
 #define		PS_ERROR	7	/* some kind of POP3 error condition */
+#define		PS_EXCLUDE	8	/* exclusion error */
 #define		PS_UNDEFINED	9	/* something I hadn't thought of */
 
 /* output noise level */
@@ -143,6 +147,7 @@ extern int yydebug;	/* enable parse debugging */
 /* daemon mode control */
 extern int poll_interval;	/* poll interval in seconds */
 extern char *logfile;		/* log file for daemon mode */
+extern int quitmode;		/* if --quit was set */
 
 extern char *prc_pathname;	/* path name of rc file */
 
@@ -163,7 +168,7 @@ char *MD5Digest (char *);
 char *prc_getpathname (struct optrec *cmd_opts, struct optrec *def_opts);
 void reply_hack(char *buf, const char *host);
 void append_server_names(int *pargc, char **argv);
-int daemonize(const char *logfile);
+int daemonize(const char *logfile, void (*)(void));
 
 #else
 
diff --git a/fetchmail.man b/fetchmail.man
index 46ee9f94..8eca7854 100644
--- a/fetchmail.man
+++ b/fetchmail.man
@@ -16,6 +16,9 @@
 \.  */
 \.
 \. $Log: fetchmail.man,v $
+\. Revision 1.3  1996/06/27 19:22:33  esr
+\. Sent to ceharris.
+\.
 \. Revision 1.2  1996/06/26 19:09:00  esr
 \. This is what I sent Harris.
 \.
@@ -371,6 +374,12 @@ popmail -d 900
 will, therefore, poll the hosts described in your 
 .I ~/.poprc
 file once every fifteen minutes.
+.PP
+Only one daemon process is permitted per user; in daemon mode,
+.I popclient
+makes a per-user lockfile to guarantee this.  The option
+.B --quit
+will kill a running daemon process.
 .SH THE POPRC FILE
 The preferred way to set up popclient (and the only way if you want to
 specify a password) is to write a .poprc file in your home directory.
@@ -520,6 +529,11 @@ There was a syntax error in the arguments to
 Some kind of I/O woes occurred when writing to the local folder.
 .IP 7
 There was an error condition reported by the server (POP3 only).
+.IP 8
+Exclusion error.  This means 
+.I popclient
+either found another copy of itself already running, or failed in such
+a way that it isn't sure whether another copy is running.
 .IP 9
 Something totally undefined occured.  This is usually caused by a bug within
 .I popclient.
diff --git a/options.c b/options.c
index 47c92094..199a182f 100644
--- a/options.c
+++ b/options.c
@@ -22,6 +22,9 @@
   description:	command-line option processing
   
   $Log: options.c,v $
+  Revision 1.3  1996/06/27 19:22:32  esr
+  Sent to ceharris.
+
   Revision 1.2  1996/06/26 19:08:57  esr
   This is what I sent Harris.
 
@@ -87,7 +90,8 @@
 #define	LA_LOCALFILE	15
 #define LA_MDA		16
 #define LA_LOGFILE	17
-#define LA_YYDEBUG	18
+#define LA_QUIT		18
+#define LA_YYDEBUG	19
  
 static char *shortoptions = "23VaKkvscl:Fd:f:u:r:o:m:";
 static struct option longoptions[] = {
@@ -110,6 +114,7 @@ static struct option longoptions[] = {
   {"local",     required_argument, (int *) 0, LA_LOCALFILE  },
   {"mda",	required_argument, (int *) 0, LA_MDA        },
   {"logfile",	required_argument, (int *) 0, LA_LOGFILE    },
+  {"quit",	no_argument,	   (int *) 0, LA_QUIT       },
   {"yydebug",	no_argument,	   (int *) 0, LA_YYDEBUG    },
   {(char *) 0,  no_argument,       (int *) 0, 0             }
 };
@@ -260,6 +265,10 @@ struct optrec *options;
       case LA_LOGFILE:
         logfile = optarg;
         break;
+      case 'q':
+      case LA_QUIT:
+        quitmode = 1;
+        break;
       case LA_YYDEBUG:
 	yydebug = 1;
         break;
@@ -283,6 +292,7 @@ struct optrec *options;
     fputs("  -k, --keep       save new messages after retrieval\n", stderr);
     fputs("  -l, --limit      retrieve at most n message lines\n", stderr);
     fputs("  -m, --mda        set mail user agent to pass to\n", stderr);
+    fputs("  -q, --quit       kill daemon process\n", stderr);
     fputs("  -s, --silent     work silently\n", stderr);
     fputs("  -v, --verbose    work noisily (diagnostic output)\n", stderr);
     fputs("  -d, --daemon     run as a daemon once per n seconds\n", stderr);