Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!rice!sun-spots-request
From: stan!dce@ames.arc.nasa.gov (David Elliott)
Newsgroups: comp.sys.sun
Subject: Patch to restrict wall messages
Keywords: Software
Message-ID: <667@salgado.stan.UUCP>
Date: 21 Apr 89 18:20:47 GMT
Sender: usenet@rice.edu
Organization: Solbourne Computer Inc., Longmont, Colorado
Lines: 147
Approved: Sun-Spots@rice.edu
Original-Date: 24 Mar 89 02:48:06 GMT
X-Sun-Spots-Digest: Volume 7, Issue 235, message 15 of 15

Enclosed is a patch to the SunOS 4.0 wall command that makes sure that
wall messages (such as those produced by shutdown) only go to one window
per person per "hostname".  An empty remote hostname is assumed to be the
local host, as is a hostname beginning with "unix:" (for local X clients).
The code also handles remote X clients.  Note that the message goes to the
first tty it finds for each user/hostname.

*** wall.c.orig	Thu Mar 23 19:38:53 1989
--- wall.c	Thu Mar 16 11:23:25 1989
***************
*** 29,38 ****
  #include <fcntl.h>
  #include <sys/types.h>
  #include <sys/stat.h>

  #define IGNOREUSER	"sleeper"

! char	hostname[32];
  char	mesg[3000];
  int		msize,sline;
  struct	utmp *utmp;
--- 29,39 ----
  #include <fcntl.h>
  #include <sys/types.h>
  #include <sys/stat.h>
+ #include <sys/param.h>

  #define IGNOREUSER	"sleeper"

! char	hostname[MAXHOSTNAMELEN + 1];
  char	mesg[3000];
  int		msize,sline;
  struct	utmp *utmp;
***************
*** 116,123 ****
  		/*
  		 * if (-a option OR remote OR NOT tty[pqr]), send the message
  		 */
! 		if (aflag || !nonuser(*p))
  			sendmes(p->ut_line);
  	}
  	exit(0);
  }
--- 117,129 ----
  		/*
  		 * if (-a option OR remote OR NOT tty[pqr]), send the message
  		 */
! 		if (aflag) {
  			sendmes(p->ut_line);
+ 		} else {
+ 			if (!already(p) && !nonuser(*p)) {
+ 				sendmes(p->ut_line);
+ 			}
+ 		}
  	}
  	exit(0);
  }
***************
*** 166,169 ****
--- 172,255 ----
  	}
  	(void) write(f, mesg, msize);
  	exit(0);
+ }
+ 
+ /*
+  * already() returns a 1 if the named user/machine pair has already
+  * been sent the message.
+  */
+ 
+ struct cacheut {
+ 	char cu_name[16];
+ 	char cu_host[MAXHOSTNAMELEN + 1];
+ 	struct cacheut *next;
+ };
+ 
+ struct cacheut *UtHead;
+ 
+ already(ut)
+ 	struct utmp *ut;
+ {
+ 	register struct cacheut *cur;
+ 	char userhost[MAXHOSTNAMELEN + 1];
+ 
+ 	gethost(ut->ut_host, userhost);
+ 
+ 	cur = UtHead;
+ 	while (cur) {
+ #ifdef DEBUG
+ 	printf("Comparing <%s, %s(%s)> to <%s, %s>\n", ut->ut_name,
+ 	ut->ut_host, userhost, cur->cu_name, cur->cu_host);
+ #endif
+ 		if (strcmp(cur->cu_name, ut->ut_name) == 0 &&
+ 		    strcmp(cur->cu_host, userhost) == 0) {
+ #ifdef DEBUG
+ 			printf("Match\n");
+ #endif
+ 			return 1;
+ 		}
+ 		cur = cur->next;
+ 	}
+ 
+ 	cur = (struct cacheut *)malloc(sizeof (struct cacheut));
+ 	if (cur == NULL) {
+ 		fprintf(stderr, "wall: Out of memory\n");
+ 		exit(1);
+ 	}
+ 	strcpy (cur->cu_name, ut->ut_name);
+ 	strcpy (cur->cu_host, userhost);
+ 
+ 	if (UtHead) {
+ 		cur->next = UtHead;
+ 	} else {
+ 		cur->next = NULL;
+ 	}
+ 	UtHead = cur;
+ 
+ 	return 0;
+ }
+ 
+ gethost(src, dest)
+ 	char *src;
+ 	char *dest;
+ {
+ 
+ 	char *ind;
+ 
+ 	if (*src == '\0') {
+ 		strcpy(dest, hostname);
+ 		return;
+ 	}
+ 
+ 	ind = (char *)index(src, ':');
+ 	if (ind == NULL) {
+ 		strcpy(dest, src);
+ 		return;
+ 	}
+ 	strncpy(dest, src, ind - src);
+ 	dest[ind - src] = '\0';
+ 
+ 	if (strcmp(dest, "unix") == 0) {
+ 		strcpy(dest, hostname);
+ 	}
  }
-- 
David Elliott		...!pyramid!boulder!stan!dce
"Splish splash, I was rakin' in the cash"  -- Eno