--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib-src/gnuserv.c	Mon Aug 13 08:45:50 2007 +0200
@@ -0,0 +1,857 @@
+/* -*-C-*-
+ Server code for handling requests from clients and forwarding them
+ on to the GNU Emacs process.
+
+ This file is part of GNU Emacs.
+
+ Copying is permitted under those conditions described by the GNU
+ General Public License.
+
+ Copyright (C) 1989 Free Software Foundation, Inc.
+
+ Author: Andy Norman (ange@hplb.hpl.hp.com), based on 'etc/server.c'
+         from the 18.52 GNU Emacs distribution.
+
+ Please mail bugs and suggestions to the author at the above address.
+*/
+
+/* HISTORY 
+ * 11-Nov-1990		bristor@simba	
+ *    Added EOT stuff.
+ */
+
+/*
+ * This file incorporates new features added by Bob Weiner <weiner@mot.com>,
+ * Darrell Kindred <dkindred@cmu.edu> and Arup Mukherjee <arup@cmu.edu>.
+ * Please see the note at the end of the README file for details.
+ *
+ * (If gnuserv came bundled with your emacs, the README file is probably
+ * ../etc/gnuserv.README relative to the directory containing this file)
+ */
+
+#if 0
+static char rcsid [] = "!Header: gnuserv.c,v 2.1 95/02/16 11:58:27 arup alpha !";
+#endif
+
+#include "gnuserv.h"
+
+#ifdef USE_LITOUT
+#ifdef linux
+#include <bsd/sgtty.h>
+#else
+#include <sgtty.h>
+#endif
+#endif
+
+#ifdef AIX
+#include <sys/select.h>
+#endif
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <string.h>
+
+#if !defined(SYSV_IPC) && !defined(UNIX_DOMAIN_SOCKETS) && \
+    !defined(INTERNET_DOMAIN_SOCKETS)
+main ()
+{
+  fprintf (stderr,"Sorry, the Emacs server is only supported on systems that have\n");
+  fprintf (stderr,"Unix Domain sockets, Internet Domain sockets or System V IPC\n");
+  exit (1);
+} /* main */
+#else /* SYSV_IPC || UNIX_DOMAIN_SOCKETS || INTERNET_DOMAIN_SOCKETS */
+
+#ifdef SYSV_IPC
+
+int ipc_qid = 0;		/* ipc message queue id */
+int ipc_wpid = 0;		/* watchdog task pid */
+
+
+/*
+  ipc_exit -- clean up the queue id and queue, then kill the watchdog task
+              if it exists. exit with the given status.
+*/
+void ipc_exit(stat)
+     int stat;
+{
+  msgctl(ipc_qid,IPC_RMID,0);
+  
+  if (ipc_wpid != 0)
+    kill(ipc_wpid,SIGKILL);
+
+  exit(stat);
+} /* ipc_exit */
+
+
+/*
+  ipc_handle_signal -- catch the signal given and clean up.
+*/
+void ipc_handle_signal(sig)
+     int sig;
+{
+  ipc_exit(0);
+} /* ipc_handle_signal */
+
+
+/* 
+  ipc_spawn_watchdog -- spawn a watchdog task to clean up the message queue should the
+			server process die.
+*/
+void ipc_spawn_watchdog()
+{
+  if ((ipc_wpid = fork()) == 0) { /* child process */
+    int ppid = getppid();	/* parent's process id */
+
+    setpgrp();			/* gnu kills process group on exit */
+    
+    while (1) {
+      if (kill(ppid,0) < 0) {	/* ppid is no longer valid, parent may have died */
+	ipc_exit(0);
+      } /* if */
+
+      sleep(10);		/* have another go later */
+    } /* while */
+  } /* if */
+
+} /* ipc_spawn_watchdog */
+
+
+/*
+  ipc_init -- initialize server, setting the global msqid that can be listened on.
+*/
+void ipc_init(msgpp)
+     struct msgbuf **msgpp;
+{
+  key_t key;			/* messge key */
+  char buf[GSERV_BUFSZ];	/* pathname for key */
+
+  sprintf(buf,"/tmp/gsrv%d",(int)geteuid());
+  creat(buf,0600);
+  key = ftok(buf,1);
+
+  if ((ipc_qid = msgget(key,0600|IPC_CREAT)) == -1) {
+    perror(progname);
+    fprintf(stderr,"%s: unable to create msg queue\n",progname);
+    ipc_exit(1);
+  } /* if */
+
+  ipc_spawn_watchdog();
+
+  signal(SIGTERM,ipc_handle_signal);
+  signal(SIGINT,ipc_handle_signal);
+
+  if ((*msgpp = (struct msgbuf *) 
+                malloc(sizeof **msgpp + GSERV_BUFSZ)) == NULL) {
+    fprintf(stderr,
+	    "%s: unable to allocate space for message buffer\n",progname);
+    ipc_exit(1);
+  } /* if */
+
+} /* ipc_init */
+
+
+/*
+  handle_ipc_request -- accept a request from a client, pass the request on
+  			to the GNU Emacs process, then wait for its reply and
+			pass that on to the client.
+*/
+void handle_ipc_request(msgp)
+     struct msgbuf *msgp;	/* message buffer */
+{
+  struct msqid_ds msg_st;	/* message status */
+  char buf[GSERV_BUFSZ];
+  int len;			/* length of message / read */
+  int s, result_len;            /* tag fields on the response from emacs */
+  int offset = 0;
+  int total = 1;                /* # bytes that will actually be sent off */
+
+  if ((len = msgrcv(ipc_qid,msgp,GSERV_BUFSZ-1,1,0)) < 0) {
+    perror(progname);
+    fprintf(stderr,"%s: unable to receive\n",progname);
+    ipc_exit(1);
+  } /* if */
+
+  msgctl(ipc_qid,IPC_STAT,&msg_st);
+  strncpy(buf,msgp->mtext,len);
+  buf[len] = '\0';		/* terminate */
+  
+  printf("%d %s",ipc_qid,buf);
+  fflush(stdout);
+
+  /* now for the response from gnu */
+  msgp->mtext[0] = '\0';
+
+#if 0
+  if ((len = read(0,buf,GSERV_BUFSZ-1)) < 0) {
+    perror(progname);
+    fprintf(stderr,"%s: unable to read\n",progname);
+    ipc_exit(1);
+  } /* if */
+      
+  sscanf(buf,"%d:%[^\n]\n",&junk,msgp->mtext);
+#else 
+
+  /* read in "n/m:" (n=client fd, m=message length) */
+
+  while (offset < (GSERV_BUFSZ-1) && 
+	 ((len = read(0,buf+offset,1)) > 0) &&
+	 buf[offset] != ':') {
+    offset += len;
+  }
+
+  if (len < 0) {
+    perror(progname);
+    fprintf(stderr,"%s: unable to read\n",progname);
+    exit(1);
+  }
+      
+  /* parse the response from emacs, getting client fd & result length */
+  buf[offset] = '\0';
+  sscanf(buf,"%d/%d", &s, &result_len);
+
+  while (result_len > 0) {
+    if ((len = read(0,buf,min2(result_len, GSERV_BUFSZ - 1))) < 0) {
+      perror(progname);
+      fprintf(stderr,"%s: unable to read\n",progname);
+      exit(1);
+    }
+
+    /* Send this string off, but only if we have enough space */ 
+
+    if (GSERV_BUFSZ > total) {
+      if (total + len <= GSERV_BUFSZ)
+	buf[len] = 0;
+      else 
+	buf[GSERV_BUFSZ - total] = 0;
+
+      send_string(s,buf);
+      total += strlen(buf);
+    }
+
+    result_len -= len;
+  }
+
+  /* eat the newline */
+  while ((len = read(0,buf,1)) == 0)
+    ;
+  if (len < 0) {
+    perror(progname);
+    fprintf(stderr,"%s: unable to read\n",progname);
+    exit(1);
+  }
+  if (buf[0] != '\n') {
+    fprintf(stderr,"%s: garbage after result [%c]\n",progname, buf[0]);
+    exit(1);
+  }
+#endif
+
+  /* Send a response back to the client. */
+
+  msgp->mtype = msg_st.msg_lspid;
+  if (msgsnd(ipc_qid,msgp,strlen(msgp->mtext)+1,0) < 0)
+    perror("msgsend(gnuserv)");
+
+} /* handle_ipc_request */
+#endif /* SYSV_IPC */
+
+
+#if defined(INTERNET_DOMAIN_SOCKETS) || defined(UNIX_DOMAIN_SOCKETS)
+/*
+  echo_request -- read request from a given socket descriptor, and send the information
+                  to stdout (the gnu process).
+*/
+static void
+echo_request (int s)
+{
+  char buf[GSERV_BUFSZ];
+  int len;
+
+  printf("%d ",s);
+  
+  /* read until we get a newline or no characters */
+  while ((len = recv(s,buf,GSERV_BUFSZ-1,0)) > 0) {
+    buf[len] = '\0';
+    printf("%s",buf);
+
+    if (buf[len-1] == EOT_CHR) {
+      fflush(stdout);
+      break;			/* end of message */
+    }
+
+  } /* while */
+
+  if (len < 0) {
+    perror(progname);
+    fprintf(stderr,"%s: unable to recv\n",progname);
+    exit(1);
+  } /* if */
+  
+} /* echo_request */
+
+
+/*
+  handle_response -- accept a response from stdin (the gnu process) and pass the
+                     information on to the relevant client.
+*/
+static void
+handle_response (void)
+{
+  char buf[GSERV_BUFSZ+1];
+  int offset=0;
+  int s;
+  int len;
+  int result_len;
+
+  /* read in "n/m:" (n=client fd, m=message length) */
+  while (offset < GSERV_BUFSZ && 
+	 ((len = read(0,buf+offset,1)) > 0) &&
+	 buf[offset] != ':') {
+    offset += len;
+  }
+
+  if (len < 0) {
+    perror(progname);
+    fprintf(stderr,"%s: unable to read\n",progname);
+    exit(1);
+  }
+      
+  /* parse the response from emacs, getting client fd & result length */
+  buf[offset] = '\0';
+  sscanf(buf,"%d/%d", &s, &result_len);
+
+  while (result_len > 0) {
+    if ((len = read(0,buf,min2(result_len,GSERV_BUFSZ))) < 0) {
+      perror(progname);
+      fprintf(stderr,"%s: unable to read\n",progname);
+      exit(1);
+    }
+    buf[len] = '\0';
+    send_string(s,buf);
+    result_len -= len;
+  }
+
+  /* eat the newline */
+  while ((len = read(0,buf,1)) == 0)
+    ;
+  if (len < 0) {
+    perror(progname);
+    fprintf(stderr,"%s: unable to read\n",progname);
+    exit(1);
+  }
+  if (buf[0] != '\n') {
+    fprintf(stderr,"%s: garbage after result\n",progname);
+    exit(1);
+  }
+  close(s);
+
+} /* handle_response */
+#endif /* INTERNET_DOMAIN_SOCKETS || UNIX_DOMAIN_SOCKETS */
+
+
+#ifdef INTERNET_DOMAIN_SOCKETS
+struct entry {
+  u_long host_addr;
+  struct entry *next;
+};
+
+struct entry *permitted_hosts[TABLE_SIZE];
+
+#ifdef AUTH_MAGIC_COOKIE
+# include <X11/X.h>
+# include <X11/Xauth.h>
+
+static Xauth *server_xauth = NULL;
+#endif 
+
+static int 
+timed_read (int fd, char *buf, int max, int timeout, int one_line)
+{
+  fd_set rmask;
+  struct timeval tv; /* = {timeout, 0}; */
+  char c = 0;
+  int nbytes = 0;
+  int r;
+  
+  tv.tv_sec = timeout;
+  tv.tv_usec = 0;
+
+  FD_ZERO(&rmask);
+  FD_SET(fd, &rmask);
+  
+  do {
+    r = select(fd + 1, &rmask, NULL, NULL, &tv);
+
+    if (r > 0) {
+      if (read (fd, &c, 1) == 1 ){
+	*buf++ = c;
+	++nbytes;
+      } else {
+	printf ("read error on socket\004\n");
+	return -1;
+      }
+    } else if (r == 0) {
+      printf ("read timed out\004\n");
+      return -1;
+    } else {
+      printf ("error in select\004\n");
+      return -1;
+    }
+  } while ((nbytes < max) &&  !(one_line && (c == '\n')));
+
+  --buf;
+  if (one_line && *buf == '\n') {
+    *buf = 0;
+  }
+
+  return nbytes;
+}
+	
+	
+
+/*
+  permitted -- return whether a given host is allowed to connect to the server.
+*/
+static int
+permitted (u_long host_addr, int fd)
+{
+  int key;
+  struct entry *entry;
+
+  char auth_protocol[128]; 
+  char buf[1024];
+  int  auth_data_len;
+
+  if (fd > 0) {
+    /* we are checking permission on a real connection */
+
+    /* Read auth protocol name */
+  
+    if (timed_read(fd, auth_protocol, AUTH_NAMESZ, AUTH_TIMEOUT, 1) <= 0)
+      return FALSE;
+
+    if (strcmp (auth_protocol, DEFAUTH_NAME) &&
+	strcmp (auth_protocol, MCOOKIE_NAME)) {
+      printf ("authentication protocol (%s) from client is invalid...\n", 
+	      auth_protocol);
+      printf ("... Was the client an old version of gnuclient/gnudoit?\004\n");
+      
+      return FALSE;
+    }
+
+    if (!strcmp(auth_protocol, MCOOKIE_NAME)) {
+
+      /*
+       * doing magic cookie auth
+       */
+
+      if (timed_read(fd, buf, 10, AUTH_TIMEOUT, 1) <= 0)
+	return FALSE;
+
+      auth_data_len = atoi(buf);
+
+      if (timed_read(fd, buf, auth_data_len, AUTH_TIMEOUT, 0) != auth_data_len)
+	return FALSE;
+      
+#ifdef AUTH_MAGIC_COOKIE
+      if (server_xauth && server_xauth->data &&
+	  !memcmp(buf, server_xauth->data, auth_data_len)) {
+	return TRUE;
+      }
+#else 
+      printf ("client tried Xauth, but server is not compiled with Xauth\n");
+#endif
+      
+      /*
+       * auth failed, but allow this to fall through to the GNU_SECURE
+       * protocol....
+       */
+
+      printf ("Xauth authentication failed, trying GNU_SECURE auth...\004\n");
+
+    }
+    
+    /* Other auth protocols go here, and should execute only if the
+     * auth_protocol name matches.
+     */
+
+  }
+
+
+  /* Now, try the old GNU_SECURE stuff... */
+  
+  /* First find the hash key */
+  key = HASH(host_addr) % TABLE_SIZE;
+  
+  /* Now check the chain for that hash key */
+  for(entry=permitted_hosts[key]; entry != NULL; entry=entry->next)
+    if (host_addr == entry->host_addr) 
+      return(TRUE);
+  
+  return(FALSE);
+
+} /* permitted */
+
+
+/* 
+  add_host -- add the given host to the list of permitted hosts, provided it isn't
+              already there.
+*/	
+static void
+add_host (u_long host_addr)
+{
+  int key;
+  struct entry *new_entry;
+  
+  if (!permitted(host_addr, -1)) {
+    if ((new_entry = (struct entry *) malloc(sizeof(struct entry))) == NULL) {
+      fprintf(stderr,"%s: unable to malloc space for permitted host entry\n",
+	      progname);
+      exit(1);
+    } /* if */
+
+    new_entry->host_addr = host_addr;
+    key = HASH(host_addr) % TABLE_SIZE;
+    new_entry->next = permitted_hosts[key];
+    permitted_hosts[key] = new_entry;
+  } /* if */
+
+} /* add_host */
+
+
+/*
+  setup_table -- initialise the table of hosts allowed to contact the server,
+                 by reading from the file specified by the GNU_SECURE
+		 environment variable
+                 Put in the local machine, and, if a security file is specifed,
+                 add each host that is named in the file.
+		 Return the number of hosts added.
+*/
+static int
+setup_table (void)
+{
+  FILE *host_file;
+  char *file_name;
+  char hostname[HOSTNAMSZ];
+  u_int host_addr;
+  int i, hosts=0;
+  
+  /* Make sure every entry is null */
+  for (i=0; i<TABLE_SIZE; i++)
+    permitted_hosts[i] = NULL;
+
+  gethostname(hostname,HOSTNAMSZ);
+
+  if ((host_addr = internet_addr(hostname)) == -1) {
+    fprintf(stderr,"%s: unable to find %s in /etc/hosts or from YP", 
+	    progname,hostname);
+    exit(1);
+  } /* if */
+
+#ifdef AUTH_MAGIC_COOKIE
+  
+  server_xauth = XauGetAuthByAddr (FamilyInternet, 
+				   sizeof(host_addr), (char *)&host_addr,
+				   strlen(MCOOKIE_SCREEN), MCOOKIE_SCREEN, 
+				   strlen(MCOOKIE_X_NAME), MCOOKIE_X_NAME);
+  hosts++;
+
+#endif /* AUTH_MAGIC_COOKIE */
+  
+
+#if 0 /* Don't even want to allow access from the local host by default */
+  add_host(host_addr);					/* add local host */
+#endif 
+
+  if (((file_name = getenv("GNU_SECURE")) != NULL &&    /* security file  */
+       (host_file = fopen(file_name,"r")) != NULL)) {	/* opened ok */
+    while ((fscanf(host_file,"%s",hostname) != EOF))	/* find a host */
+      if ((host_addr = internet_addr(hostname)) != -1) {/* get its addr */
+	add_host(host_addr);				/* add the addr */
+        hosts++;
+      }
+    fclose(host_file);
+  } /* if */
+
+  return hosts;
+} /* setup_table */
+
+
+/*
+  internet_init -- initialize server, returning an internet socket that can
+                    be listened on.
+*/
+static int
+internet_init (void)
+{
+  int ls;			/* socket descriptor */
+  struct servent *sp;		/* pointer to service information */
+  struct sockaddr_in server;	/* for local socket address */
+  char *ptr;			/* ptr to return from getenv */
+
+  if (setup_table() == 0) 
+    return -1;
+
+  /* clear out address structure */
+  memset((char *)&server,0,sizeof(struct sockaddr_in));
+  
+  /* Set up address structure for the listen socket. */
+  server.sin_family = AF_INET;
+  server.sin_addr.s_addr = INADDR_ANY;
+
+  /* Find the information for the gnu server
+   * in order to get the needed port number.
+   */
+  if ((ptr=getenv("GNU_PORT")) != NULL)
+    server.sin_port = htons(atoi(ptr));
+  else if ((sp = getservbyname ("gnuserv", "tcp")) == NULL)
+    server.sin_port = htons(DEFAULT_PORT+getuid());
+  else
+    server.sin_port = sp->s_port;
+  
+  /* Create the listen socket. */
+  if ((ls = socket (AF_INET,SOCK_STREAM, 0)) == -1) {
+    perror(progname);
+    fprintf(stderr,"%s: unable to create socket\n",progname);
+    exit(1);
+  } /* if */
+  
+  /* Bind the listen address to the socket. */
+  if (bind(ls,(struct sockaddr *) &server,sizeof(struct sockaddr_in)) == -1) {
+    perror(progname);
+    fprintf(stderr,"%s: unable to bind socket\n",progname);
+    exit(1);
+  } /* if */
+
+  /* Initiate the listen on the socket so remote users
+   * can connect. 
+   */
+  if (listen(ls,20) == -1) {
+    perror(progname);
+    fprintf(stderr,"%s: unable to listen\n",progname);
+    exit(1);
+  } /* if */
+
+  return(ls);
+
+} /* internet_init */
+
+
+/*
+  handle_internet_request -- accept a request from a client and send the information
+                             to stdout (the gnu process).
+*/
+static void
+handle_internet_request (int ls)
+{
+  int s;
+  int addrlen = sizeof(struct sockaddr_in);
+  struct sockaddr_in peer;	/* for peer socket address */
+
+  memset((char *)&peer,0,sizeof(struct sockaddr_in));
+
+  if ((s = accept(ls,(struct sockaddr *)&peer,&addrlen)) == -1) {
+    perror(progname);
+    fprintf(stderr,"%s: unable to accept\n",progname);
+    exit(1);
+  } /* if */
+    
+  /* Check that access is allowed - if not return crud to the client */
+  if (!permitted(peer.sin_addr.s_addr, s)) {
+    send_string(s,"gnudoit: Connection refused\ngnudoit: unable to connect to remote");
+    close(s);
+
+    printf("Refused connection from %s\004\n", inet_ntoa(peer.sin_addr));
+    return;
+  } /* if */
+
+  echo_request(s);
+  
+} /* handle_internet_request */
+#endif /* INTERNET_DOMAIN_SOCKETS */
+
+
+#ifdef UNIX_DOMAIN_SOCKETS
+/*
+  unix_init -- initialize server, returning an unix-domain socket that can
+               be listened on.
+*/
+static int
+unix_init (void)
+{
+  int ls;			/* socket descriptor */
+  struct sockaddr_un server; 	/* unix socket address */
+  int bindlen;
+
+  if ((ls = socket(AF_UNIX,SOCK_STREAM, 0)) < 0) {
+    perror(progname);
+    fprintf(stderr,"%s: unable to create socket\n",progname);
+    exit(1);
+  } /* if */
+
+  /* Set up address structure for the listen socket. */
+#ifdef HIDE_UNIX_SOCKET
+  sprintf(server.sun_path,"/tmp/gsrvdir%d",(int)geteuid());
+  if (mkdir(server.sun_path, 0700) < 0) {
+    /* assume it already exists, and try to set perms */
+    if (chmod(server.sun_path, 0700) < 0) {
+      perror(progname);
+      fprintf(stderr,"%s: can't set permissions on %s\n",
+	      progname, server.sun_path);
+      exit(1);
+    }
+  }
+  strcat(server.sun_path,"/gsrv");
+  unlink(server.sun_path);	/* remove old file if it exists */
+#else /* HIDE_UNIX_SOCKET */
+  sprintf(server.sun_path,"/tmp/gsrv%d",(int)geteuid());
+  unlink(server.sun_path);	/* remove old file if it exists */
+#endif /* HIDE_UNIX_SOCKET */
+
+  server.sun_family = AF_UNIX;
+#ifdef HAVE_SOCKADDR_SUN_LEN
+  /* See W. R. Stevens "Advanced Programming in the Unix Environment"
+     p. 502 */
+  bindlen = (sizeof (server.sun_len) + sizeof (server.sun_family)
+	     + strlen (server.sun_path) + 1);
+  server.sun_len = bindlen;
+#else
+  bindlen = strlen (server.sun_path) + sizeof (server.sun_family);
+#endif
+ 
+  if (bind(ls,(struct sockaddr *)&server,bindlen) < 0) {
+    perror(progname);
+    fprintf(stderr,"%s: unable to bind socket\n",progname);
+    exit(1);
+  } /* if */
+
+  chmod(server.sun_path,0700);	/* only this user can send commands */
+
+  if (listen(ls,20) < 0) {
+    perror(progname);
+    fprintf(stderr,"%s: unable to listen\n",progname);
+    exit(1);
+  } /* if */
+
+  /* #### there are also better ways of dealing with this when
+     sigvec() is present. */
+#if  defined (HAVE_SIGPROCMASK)
+  {						
+  sigset_t _mask;
+  sigemptyset (&_mask);
+  sigaddset (&_mask, SIGPIPE);
+  sigprocmask (SIG_BLOCK, &_mask, NULL);
+  }
+#else
+  signal(SIGPIPE,SIG_IGN);	/* in case user kills client */
+#endif
+
+  return(ls);
+
+} /* unix_init */
+
+
+/*
+  handle_unix_request -- accept a request from a client and send the information
+                         to stdout (the gnu process).
+*/
+static void
+handle_unix_request (int ls)
+{
+  int s;
+  int len = sizeof(struct sockaddr_un);
+  struct sockaddr_un server; 	/* for unix socket address */
+
+  server.sun_family = AF_UNIX;
+
+  if ((s = accept(ls,(struct sockaddr *)&server,&len)) < 0) {
+    perror(progname);
+    fprintf(stderr,"%s: unable to accept\n",progname);
+  } /* if */
+
+  echo_request(s);
+  
+} /* handle_unix_request */
+#endif /* UNIX_DOMAIN_SOCKETS */
+
+
+void
+main(argc,argv)
+     int argc;
+     char *argv[];
+{
+  int chan;			/* temporary channel number */
+#ifdef INTERNET_DOMAIN_SOCKETS
+  int ils = -1;			/* internet domain listen socket */
+#endif
+#ifdef UNIX_DOMAIN_SOCKETS
+  int uls = -1;			/* unix domain listen socket */
+#endif
+#ifdef SYSV_IPC
+  struct msgbuf *msgp;		/* message buffer */
+#endif /* SYSV_IPC */
+
+  progname = argv[0];
+
+  for(chan=3; chan < _NFILE; close(chan++)) /* close unwanted channels */
+    ;
+
+#ifdef USE_LITOUT
+  {
+    /* this is to allow ^D to pass to emacs */
+    int d = LLITOUT;
+    (void) ioctl(fileno(stdout), TIOCLBIS, &d);
+  }
+#endif
+
+#ifdef SYSV_IPC
+  ipc_init(&msgp);		/* get a msqid to listen on, and a message buffer */
+#endif /* SYSV_IPC */
+
+#ifdef INTERNET_DOMAIN_SOCKETS
+  ils = internet_init();	/* get a internet domain socket to listen on */
+#endif /* INTERNET_DOMAIN_SOCKETS */
+
+#ifdef UNIX_DOMAIN_SOCKETS
+  uls = unix_init();		/* get a unix domain socket to listen on */
+#endif /* UNIX_DOMAIN_SOCKETS */
+
+  while (1) {
+#ifdef SYSV_IPC
+    handle_ipc_request(msgp);
+#else /* NOT SYSV_IPC */
+    fd_set rmask;
+    FD_ZERO(&rmask);
+    FD_SET(fileno(stdin), &rmask);
+    if (uls >= 0)
+      FD_SET(uls, &rmask);
+    if (ils >= 0)
+      FD_SET(ils, &rmask);
+    
+    if (select(max2(fileno(stdin),max2(uls,ils)) + 1, &rmask, 
+	       (fd_set *)NULL, (fd_set *)NULL, (struct timeval *)NULL) < 0) {
+      perror(progname);
+      fprintf(stderr,"%s: unable to select\n",progname);
+      exit(1);
+    } /* if */
+
+#ifdef UNIX_DOMAIN_SOCKETS
+    if (uls > 0 && FD_ISSET(uls, &rmask))
+      handle_unix_request(uls);
+#endif
+
+#ifdef INTERNET_DOMAIN_SOCKETS
+    if (ils > 0 && FD_ISSET(ils, &rmask))
+      handle_internet_request(ils);
+#endif /* INTERNET_DOMAIN_SOCKETS */
+
+    if (FD_ISSET(fileno(stdin), &rmask))      /* from stdin (gnu process) */
+      handle_response();
+#endif /* NOT SYSV_IPC */
+  } /* while */
+
+} /* main */
+
+#endif /* SYSV_IPC || UNIX_DOMAIN_SOCKETS || INTERNET_DOMAIN_SOCKETS */