\documentclass{article}
\usepackage{axiom}

\title{\$SPAD/src/sman sman}
\author{The Axiom Team}

\begin{document}
\maketitle

\begin{abstract}
\end{abstract}
\eject

\tableofcontents
\eject

\section{sman.h}
<<sman.h>>=
/* Process control definitions.  Used by fork_you and spawn_of_hell */

/* When a process dies it kills off everything else */
#define Die 1
/* When a process dies, do nothing */
#define NadaDelShitsky  2
/* When a process dies start it up again */
#define DoItAgain       3
/* When hypertex dies, clean its socket */
#define CleanHypertexSocket 4

typedef struct spad_proc {
  int	proc_id;	/* process id of child */
  int	death_action;	/* one of the above constants */
  char	*command;	/* sh command line to restart the process */
  struct spad_proc *next;
} SpadProcess;

@
\section{sman}
\subsection{includes}
<<includes>>=
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <pwd.h>
#include <fcntl.h>
#include <termios.h>
#include <errno.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <signal.h>

#include "axiom-c-macros.h"

#if defined(SUN4OS5platform) || defined(HP10platform)
#include <sys/stropts.h>
#endif

#include "com.h"
#include "bsdsignal.h"
#include "sman.h"

#include "bsdsignal.H1"
#include "sockio-c.H1"
#include "openpty.H1"
#include "sman.H1"

@
\subsection{variables}
We add a debug flag so we can print information about what \Tool{sman}
is trying to do. This change is pervasive as it touches nearly every
routine.
<<debugflag>>=
int tpd=0;                      /* to-print-debug information */
@
This line is no longer used. We would completely elide it except that
it would raise spurious issues about deleting credit and/or copyright
information.
\begin{verbatim}
char *start_line =
"AKCL (Austin Kyoto Common Lisp)  Version(1.568) Thu Aug 22 16:49:01 EDT 1991\
\r\nContains Enhancements by W. Schelter\r\n";
\end{verbatim}
We modified the place where the command list lives. 
The command list used to live in
\begin{verbatim}
$AXIOM/../../share/algebra/command.list
\end{verbatim}
but the open source version of the system no longer has a share
subdirectory so we move this to the lib subdirectory.
<<clefprogram>>=
char	*ClefProgram            = 
           "$AXIOM/bin/clef -f $AXIOM/lib/command.list -e ";
@
and we change the command line arguments
<<clefprogram1>>=
      ClefProgram = 
        strcat(ClefCommandLine, " -f $AXIOM/lib/command.list -e ");
@
<<variables>>=
char *ws_path;                  /* location of the AXIOM executable */
int start_clef;			/* start clef under spad */
int start_graphics;		/* start the viewman */
int start_nagman;               /* start the nagman */
int start_ht;			/* start hypertex */
int start_spadclient;		/* Start the client spad buffer */
int start_local_spadclient;	/* Start the client spad buffer */
int use_X;			/* Use the X windows environment */
int server_num;			/* AXIOM server number */
<<debugflag>>

/************************************************/
/* definitions of programs which sman can start */
/************************************************/

char	*GraphicsProgram        = "$AXIOM/lib/viewman";
char    *NagManagerProgram      = "$AXIOM/lib/nagman";
char	*HypertexProgram        = "$AXIOM/lib/hypertex -s";
<<clefprogram>>
char	*SessionManagerProgram  = "$AXIOM/lib/session";
char	*SpadClientProgram      = "$AXIOM/lib/spadclient";
char	*PasteFile		= NULL;
char	*MakeRecordFile		= NULL;
char	*VerifyRecordFile	= NULL;

SpadProcess *spad_process_list = NULL;
/***************************/
/* sman defaults file name */
/***************************/

#define SpadDefaultFile "spadprof.input"

char ClefCommandLine[256];

#define BufSize      4096 	/* size of communication buffer */
char big_bad_buf[BufSize];      /* big I/O buffer */

Sock *session_io = NULL;        /* socket connecting to session manager */

/***********************************************************/
/* Some characters used and externally defined in edible.h */
/***********************************************************/

unsigned char  _INTR, _QUIT, _ERASE, _KILL, _EOF, _EOL, _RES1, _RES2;

/*************************************/
/* Stuff for opening pseudo-terminal */
/*************************************/

int ptsNum, ptcNum;
char ptsPath[20], ptcPath[20];

char **new_envp;                /* new environment for AXIOM */
int child_pid;                  /* child's process id */
struct termios oldbuf;           /* the original settings */
struct termios childbuf;         /* terminal structure for user i/o */


int nagman_signal=0;
int death_signal = 0;

@
\subsection{process\_arguments}
<<processarguments>>=
static void
process_arguments(int argc,char ** argv)
{
  int arg;
  if (tpd == 1) fprintf(stderr,"sman:process_arguments entered\n");
  for (arg = 1; arg < argc; arg++) {
    if      (strcmp(argv[arg], "-debug")      == 0)
      tpd = 1;
    else if (strcmp(argv[arg], "-noclef")      == 0)
      start_clef = 0;
    else if (strcmp(argv[arg], "-clef")        == 0)
      start_clef = 1;
    else if (strcmp(argv[arg], "-gr")          == 0)
      start_graphics = 1;
    else if (strcmp(argv[arg], "-nogr")        == 0)
      start_graphics = 0;
    else if (strcmp(argv[arg], "-nag")          == 0)
      start_nagman = 1;
    else if (strcmp(argv[arg], "-nonag")        == 0)
      start_nagman = 0;
    else if (strcmp(argv[arg], "-ht")          == 0)
      start_ht = 1;
    else if (strcmp(argv[arg], "-noht")        == 0)
      start_ht = 0;
    else if (strcmp(argv[arg], "-iw")          == 0)
      start_spadclient = 1;
    else if (strcmp(argv[arg], "-ihere")       == 0)
      start_local_spadclient = 1;
    else if (strcmp(argv[arg], "-noihere")     == 0)
      start_local_spadclient = 0;
    else if (strcmp(argv[arg], "-noiw")        == 0)
      start_spadclient = 0;
    else if (strcmp(argv[arg], "-ws")          == 0)
      ws_path = argv[++arg];
    else if (strcmp(argv[arg], "-comp")        == 0)
      ws_path = "$AXIOM/etc/images/comp";
    else if (strcmp(argv[arg], "-nox")         == 0)
      {
	use_X = 0;
	start_local_spadclient = 1;
	start_spadclient = 0;
	start_ht = 0;
	start_graphics = 0;
      }
    else if (strcmp(argv[arg], "-grprog")      == 0)
      GraphicsProgram = argv[++arg];
    else if (strcmp(argv[arg], "-nagprog")      == 0)
      NagManagerProgram = argv[++arg];
    else if (strcmp(argv[arg], "-htprog")      == 0)
      HypertexProgram = argv[++arg];
    else if (strcmp(argv[arg], "-clefprog")    == 0) {
      strcpy(ClefCommandLine,argv[++arg]);
<<clefprogram1>>
    }
    else if (strcmp(argv[arg], "-sessionprog") == 0)
      SessionManagerProgram = argv[++arg];
    else if (strcmp(argv[arg], "-clientprog")  == 0)
      SpadClientProgram = argv[++arg];
    else if (strcmp(argv[arg], "-rm")  == 0)
      MakeRecordFile = argv[++arg];
    else if (strcmp(argv[arg], "-rv")  == 0)
      VerifyRecordFile = argv[++arg];
    else if (strcmp(argv[arg], "-paste")  == 0)
      PasteFile = argv[++arg];
    else {
      fprintf(stderr, "Usage: sman <-clef|-noclef> \
<-gr|-nogr> <-ht|-noht> <-iw|-noiw> <-nag|-nonag> <-nox> <-comp> <-ws spad_workspace> \
<-grprog path> <-htprog path> <-clefprog path> <-sessionprog path> <-nagprog path> \
<-clientprog path>\n");
      exit(-1);
    }
  }
  if (tpd == 1)
  { fprintf(stderr,"  sman ");
    if (start_clef == 0)
      fprintf(stderr,"-noclef ");
    else
      fprintf(stderr,"-clef ");
    if (start_graphics == 0)
      fprintf(stderr,"-nogr ");
    else
      fprintf(stderr,"-gr ");
    if (start_nagman == 0)
      fprintf(stderr,"-nonag ");
    else
      fprintf(stderr,"-nag ");
    if (start_ht == 0)
      fprintf(stderr,"-noht ");
    else
      fprintf(stderr,"-ht ");
    if (start_spadclient == 0)
      fprintf(stderr,"-noiw ");
    else
      fprintf(stderr,"-iw ");
    if (start_local_spadclient == 0)
      fprintf(stderr,"-noihere ");
    else
      fprintf(stderr,"-ihere ");
    if (start_local_spadclient == 0)
      fprintf(stderr,"-noihere ");
    else
      fprintf(stderr,"-ihere ");
    if (use_X == 0)
      fprintf(stderr,"-nox ");
    fprintf(stderr,"-ws ");
    fprintf(stderr,"'%s' ",ws_path);
    fprintf(stderr,"-grprog ");
    fprintf(stderr,"'%s' ",GraphicsProgram);
    fprintf(stderr,"-nagprog ");
    fprintf(stderr,"'%s' ",NagManagerProgram);
    fprintf(stderr,"-htprog ");
    fprintf(stderr,"'%s' ",HypertexProgram);
    fprintf(stderr,"-clefprog ");
    fprintf(stderr,"'%s' ",ClefCommandLine);
    fprintf(stderr,"-sessionprog ");
    fprintf(stderr,"'%s' ",SessionManagerProgram);
    fprintf(stderr,"-clientprog ");
    fprintf(stderr,"'%s' ",SpadClientProgram);
    fprintf(stderr,"-rm ");
    fprintf(stderr,"'%s' ",MakeRecordFile);
    fprintf(stderr,"-rv ");
    fprintf(stderr,"'%s' ",VerifyRecordFile);
    fprintf(stderr,"-paste ");
    fprintf(stderr,"'%s' ",PasteFile);
    fprintf(stderr,"\n");
  }
  if (tpd == 1) fprintf(stderr,"sman:process_arguments exit\n");
}

@
\subsection{should\_I\_clef}
<<shouldIclef>>=
static int
should_I_clef(void)
{
  return(1);
}

@
\subsection{in\_X}
<<inX>>=
static int 
in_X(void)
{
  if (getenv("DISPLAY")) return 1;
  return 0;
}

@
\subsection{set\_up\_defaults}
These are the default values for sman. A '1' value means that
sman will try to start the given process, a '0' value means not
starting the process.

We do not have replacement code for the [[nagman]] process nor
do we have a copy of the [[nag fortran library]] to test the process.
Until this changes we set [[start_nagman = 0]] in order to disable
starting this process by default.
<<setupdefaults>>=
static  void
set_up_defaults(void)
{
  if (tpd == 1) fprintf(stderr,"sman:set_up_defaults entered\n");
  start_clef = should_I_clef();
  start_graphics = 1;
  start_nagman = 0;
  start_ht = 1;
  start_spadclient = 0;
  start_local_spadclient = 1;
  use_X = isatty(0) && in_X();
  ws_path = "$AXIOM/bin/AXIOMsys";
  if (tpd == 1) fprintf(stderr,"sman:set_up_defaults exit\n");
}

@
\subsection{process\_options}
<<processoptions>>=
static void
process_options(int argc, char **argv)
{
  if (tpd == 1) fprintf(stderr,"sman:process_options entered\n");
  set_up_defaults();
  process_arguments(argc, argv);
  if (tpd == 1) fprintf(stderr,"sman:process_options exit\n");
}

@
\subsection{death\_handler}
<<deathhandler>>=
static void
death_handler(int sig)
{
  death_signal = 1;
}

@
\subsection{nagman\_handler}
<<nagmanhandler>>=
static void 
nagman_handler(int sig)
{
  nagman_signal=1;
}

@
\subsection{sman\_catch\_signals}
<<smancatchsignals>>=
static void
sman_catch_signals(void)
{
  
  /* Set up the signal handlers for sman */
  bsdSignal(SIGINT,  SIG_IGN,RestartSystemCalls);
  bsdSignal(SIGTERM, death_handler,RestartSystemCalls);
  bsdSignal(SIGQUIT, death_handler,RestartSystemCalls);
  bsdSignal(SIGHUP,  death_handler,RestartSystemCalls);
  bsdSignal(SIGILL,  death_handler,RestartSystemCalls);
  bsdSignal(SIGTRAP, death_handler,RestartSystemCalls);
  bsdSignal(SIGIOT,  death_handler,RestartSystemCalls);
  bsdSignal(SIGBUS,  death_handler,RestartSystemCalls);
  bsdSignal(SIGSEGV, death_handler,RestartSystemCalls);
  /* don't restart wait call on SIGUSR1  */
  bsdSignal(SIGUSR1, nagman_handler,DontRestartSystemCalls); 
  /* ONLY nagman should send this.
     If an error (such as C-c) interrupts a NAGLINK call, nagman
     gets a signal to clean up. We need to start another nagman 
     almost immediately to process the next NAGLINK request.
     Since nagman takes a while to clean up, we treat it specially.
     nagman should send a signal (USR1) to sman.
     sman should respond by spawning a new nagman.
     
     so nagman is NOT a DoItAgain but a NadaDelShitsky.
     
     The USR1 mechanism does not work for HPUX 9 - use DoItAgain 
     */

}

@
\subsection{fix\_env}
insert SPADSERVER and SPADNUM variables into the environemnt
<<fixenv>>=
static void
fix_env(char **envp, int spadnum)
{
  int len, i;
  char *sn;
  for(len = 0; envp[len] != NULL; len++);
  new_envp = (char **) malloc((len + 3) * sizeof(char *));
  new_envp[0] = "SPADSERVER=TRUE";
  sn = (char *) malloc(20 * sizeof(char));
  sprintf(sn, "SPADNUM=%d", spadnum);
  new_envp[1] = sn;
  for(i=0; i<=len; i++)
    new_envp[i+2] = envp[i];
}

@
\subsection{init\_term\_io}
<<inittermio>>=
static void
init_term_io(void)
{
  if(!isatty(0)) return;
  if( tcgetattr(0, &oldbuf) == -1) {
    perror("getting termios");
    return ; 			/*  exit(-1); */
  }
  if( tcgetattr(0, &childbuf) == -1) {
    perror("getting termios");
    return ; 			/*   exit(-1); */
  }
  _INTR = oldbuf.c_cc[VINTR];
  _QUIT = oldbuf.c_cc[VQUIT];
  _ERASE = oldbuf.c_cc[VERASE];
  _KILL = oldbuf.c_cc[VKILL];
  _EOF = oldbuf.c_cc[VEOF];
  _EOL = oldbuf.c_cc[VEOL];
}

@
\subsection{strPrefix}
<<strPrefix>>=
static char *
strPrefix(char *prefix,char * s)
{
  while (*prefix != '\0' && *prefix == *s) {
    prefix++;
    s++;
  }
  if (*prefix == '\0') return s;
  return NULL;
}

@
\subsection{check\_spad\_proc}
<<checkspadproc>>=
static void
check_spad_proc(char *file, char *prefix)
{
  char *num;
  int pid;
  if ((num = strPrefix(prefix, file))) {
    pid = atoi(num);
    if (pid > 2) {
      kill(pid, 0);
      if (kill(pid, 0) == -1 && errno == ESRCH) {
	unlink(file);
      }
    }
  }
}

@
\subsection{clean\_up\_old\_sockets}
<<cleanupoldsockets>>=
static void
clean_up_old_sockets(void)
{
  char com[512], tmp_file[128];
  FILE *file;
  int len;
  sprintf(tmp_file, "/tmp/socks.%d", server_num);
  sprintf(com, "ls /tmp/.d* /tmp/.s* /tmp/.i* /tmp/.h* 2> %s > %s",
	  tmp_file, tmp_file);
  system(com);
  file = fopen(tmp_file, "r");
  if (file == NULL) {
    fprintf(stderr, "Can't open socket listing file\n");
    return;
  }
  while(fgets(com, 512, file) != NULL) {
    len = strlen(com);
    if (len) com[len-1] = '\0';
    else break;
    check_spad_proc(com, "/tmp/.d");
    check_spad_proc(com, "/tmp/.s");
    check_spad_proc(com, "/tmp/.i");
    check_spad_proc(com, "/tmp/.h");
  }
  fclose(file);
  unlink(tmp_file);
}

@
\subsection{fork\_you}
<<forkyou>>=
static SpadProcess *
fork_you(int death_action)
{
  /* fork a new process, giving it a default death action */
  /* return NULL in child, SpadProcess in parent          */
  int child_pid = fork();
  SpadProcess *proc;
  if (!child_pid) return NULL;
  proc = (SpadProcess *) malloc(sizeof(SpadProcess));
  proc->proc_id = child_pid;
  proc->death_action = death_action;
  proc->command = NULL;
  proc->next = spad_process_list;
  spad_process_list = proc;
  return proc;
}

@
\subsection{exec\_command\_env}
<<execcommandenv>>=
static void
exec_command_env(char *command,char ** env)
{
  char new_command[512];
  sprintf(new_command, "exec %s", command);
  execle("/bin/sh","/bin/sh", "-c", new_command, 0, env);
}

@
\subsection{spawn\_of\_hell}
<<spawnofhell>>=
static SpadProcess *
spawn_of_hell(char *command, int death_action)
{
  SpadProcess *proc = fork_you(death_action);
  if (proc != NULL) {
    proc->command = command;
    return proc;
  }
  exec_command_env(command, new_envp);
  return NULL;
}

@
\subsection{start\_the\_spadclient}
run a AXIOM client in the main process
<<startthespadclient>>=
static void
start_the_spadclient(void)
{
  char command[256];
  if (start_clef)
#ifdef RIOSplatform
    sprintf(command, 
	    "aixterm -sb -sl 500 -name axiomclient -n AXIOM -T AXIOM -e %s %s",
	    ClefProgram, SpadClientProgram);
#else
  sprintf(command, 
	  "xterm -sb -sl 500 -name axiomclient -n AXIOM -T AXIOM -e %s %s",
	  ClefProgram, SpadClientProgram);
#endif
  else
#ifdef RIOSplatform
    sprintf(command, 
	    "aixterm -sb -sl 500 -name axiomclient -n AXIOM -T AXIOM -e %s", 
	    SpadClientProgram);
#else
  sprintf(command, 
	  "xterm -sb -sl 500 -name axiomclient -n AXIOM -T AXIOM -e %s", 
	  SpadClientProgram);
#endif
  if (tpd == 1) 
    fprintf(stderr,"sman:start_the_spadclient: %s\n",command);
  spawn_of_hell(command, NadaDelShitsky);
}

@
\subsection{start\_the\_local\_spadclient}
<<startthelocalspadclient>>=
static void
start_the_local_spadclient(void)
{
  char command[256];
  if (start_clef)
    sprintf(command, "%s  %s", ClefProgram, SpadClientProgram);
  else
    sprintf(command, "%s", SpadClientProgram);
  if (tpd == 1) 
    fprintf(stderr,"sman:start_the_local_spadclient: %s\n",command);
  spawn_of_hell(command, NadaDelShitsky);
}

@
\subsection{start\_the\_nagman}
<<startthenagman>>=
static void
start_the_nagman(void)
{
#if defined(HP9platform)
  spawn_of_hell(NagManagerProgram,DoItAgain);
#else
  spawn_of_hell(NagManagerProgram,NadaDelShitsky );
#endif
}

@
\subsection{start\_the\_session\_manager}
<<startthesessionmanager>>=
static void
start_the_session_manager(void)
{
  spawn_of_hell(SessionManagerProgram, Die);
}

@
\subsection{start\_the\_hypertex}
<<startthehypertex>>=
static void
start_the_hypertex(void)
{
  char prog[512];

  if (PasteFile){
    sprintf(prog, "%s -k -ip %s", HypertexProgram, PasteFile);
    spawn_of_hell(prog, NadaDelShitsky);
  }
  else if (MakeRecordFile){
    sprintf(prog, "%s -k -rm %s", HypertexProgram,MakeRecordFile );
    spawn_of_hell(prog, NadaDelShitsky);
  }
  else if (VerifyRecordFile){
    sprintf(prog, "%s -k -rv %s", HypertexProgram, VerifyRecordFile);
    spawn_of_hell(prog, NadaDelShitsky);
  }
  else	spawn_of_hell(HypertexProgram, CleanHypertexSocket);
}

@
\subsection{start\_the\_graphics}
<<startthegraphics>>=
static void
start_the_graphics(void)
{
  spawn_of_hell(GraphicsProgram, DoItAgain);
}

@
\subsection{fork\_Axiom}
<<forkAxiom>>=
/* Start the AXIOM session in a separate process, */
/* using a pseudo-terminal to catch all input and output */
static void 
fork_Axiom(void)
{
  char augmented_ws_path[256];  /* will append directory path */
  char *tmp_pointer;
  SpadProcess *proc;

  proc =  fork_you(Die);
  child_pid = (proc == NULL ? 0 : proc->proc_id);
  switch(child_pid) {
  case -1 :
    fprintf(stderr, "Can't create a new process \n");
    exit(0);
  case 0:
    /* Dissasociate from my parents group so all my child processes */
    /* look at my terminal as the controlling terminal for the      */
    /* group                                                        */

    if(setsid() < 0) {
      perror("Dissassociating from parents group");
      exit(-1);
    }

    close(ptsNum);
    /* Now reopen the server side, so that pg, su, etc. work properly */

    if ((ptsNum =  open(ptsPath, O_RDWR)) < 0 ) {
      perror("fork_Axiom: Failed to reopen server");
      exit(-1);
    }
#if defined(SUN4OS5platform) || defined(HP10platform)
    ioctl(ptsNum,I_PUSH,"ptem");
    ioctl(ptsNum,I_PUSH,"ldterm");
#endif

    /* since I am the child, I can close ptc, and dup pts for all its */
    /* standard descriptors                                           */

    if( (dup2(ptsNum, 0) == -1) ||
        (dup2(ptsNum, 1) == -1) ||
        (dup2(ptsNum, 2) == -1)  ) {
      perror("trying to dupe the child");
      exit(-1);
    }
    close(ptcNum);
    close(ptsNum);


    /* I also have to turn off echoing, since I am echoing all the */
    /* input myself                  */

    childbuf.c_lflag &= ~ECHO;
    if( tcsetattr(0, TCSAFLUSH, &childbuf) == -1) {
      perror("setting the term buffer");
      exit(-1); 
    }
    strcpy(augmented_ws_path,ws_path);          /* write the name    */
    strcat(augmented_ws_path," ");              /* space             */
    strcat(augmented_ws_path,ws_path);          /* name again        */
    tmp_pointer = (char *)
      strrchr(augmented_ws_path,'/');      /*pointer to last /  */
    *(++tmp_pointer) = '\0';
    exec_command_env(augmented_ws_path, new_envp);

    /*    fprintf(stderr, "Cannot execute the %s system.\n", ws_path); */

    exit(0);
  }
}

@
\subsection{start\_the\_Axiom}
<<starttheAxiom>>=
static void
start_the_Axiom(char **envp)
{
  server_num = make_server_number();
  clean_up_old_sockets();
  if (server_num == -1) {
    fprintf(stderr, "could not get an AXIOM server number\n");
    exit(-1);
  }
  if (ptyopen(&ptcNum, &ptsNum, ptcPath, ptsPath) == -1) {
    perror("start_the_Axiom: ptyopen failed");
    exit(-1);
  }
  fix_env(envp, server_num);
  fork_Axiom();
  close(ptsNum);
}

@
\subsection{clean\_up\_sockets}
<<cleanupsockets>>=
static void
clean_hypertex_socket(void)
{
   char name[256];
   sprintf(name, "%s%d", MenuServerName, server_num);
   unlink(name); 
}

static void
clean_up_sockets(void)
{
  char name[256];
  sprintf(name, "%s%d", SpadServer, server_num);
  unlink(name);
  sprintf(name, "%s%d", SessionServer, server_num);
  unlink(name);
  sprintf(name, "%s%d", SessionIOName, server_num);
  unlink(name);
  clean_hypertex_socket();
}

@
\subsection{read\_from\_spad\_io}
<<readfromspadio>>=
static void
read_from_spad_io(int ptcNum)
{
  int ret_code = 0, i=0;
  static int mes_len =0; 
  ret_code = read(ptcNum, big_bad_buf, BufSize);
  if (ret_code == -1) {
    clean_up_sockets();
    exit(-1);
  }
  if (session_io == NULL) {
    if (ret_code < mes_len)
      mes_len -= ret_code;
    else {
      if (mes_len > 0) {
	i = mes_len;
	mes_len = 0;
      }
      else
	i = 0;
      ret_code = write(1, big_bad_buf+i, ret_code-i);
    }
  }
  else
    ret_code = swrite(session_io, big_bad_buf, ret_code,
		      "writing to session man");
  if (ret_code == -1) {
    perror("writing output to session manager");
    clean_up_sockets();
    exit(-1);
  }
}

@
\subsection{read\_from\_manager}
<<readfrommanager>>=
static void
read_from_manager(int ptcNum)
{
  int ret_code;
  ret_code = sread(session_io, big_bad_buf, BufSize, "reading session io");
  if (ret_code == -1) {
    return;
  }
  ret_code = write(ptcNum, big_bad_buf, ret_code);
  if (ret_code == -1) {
    return;
  }
}

@
\subsection{manage\_spad\_io}
<<managespadio>>=
static void
manage_spad_io(int ptcNum)
{
  int ret_code, i, p;
  fd_set rd;
  while (1) {
    rd = socket_mask;
    FD_SET(ptcNum, &rd);
    if (session_io != NULL)
      FD_SET(session_io->socket, &rd);
    ret_code = sselect(FD_SETSIZE, &rd, 0, 0, NULL);
    if (ret_code == -1) {
      perror("Session manager select");
      clean_up_sockets();
      exit(-1);
    }
    if (FD_ISSET(ptcNum, &rd)) {
      read_from_spad_io(ptcNum);
    }
    for(i=0; i<2; i++) {
      if (server[i].socket > 0 && FD_ISSET(server[i].socket, &rd)) {
	p = accept_connection(server+i);
	switch(p) {
	case SessionIO:
	  session_io = purpose_table[SessionIO];
	  /*  printf("connected session manager\n\r");*/
	  printf("\n");
	  break;
	default:
	  printf("sman: Unkown connection request type: %d\n", p);
	  break;
	}
      }
    }
    if (session_io != NULL && FD_ISSET(session_io->socket, &rd)) {
      read_from_manager(ptcNum);
    }
  }
}

@
\subsection{init\_spad\_process\_list}
<<initspadprocesslist>>=
static void
init_spad_process_list(void)
{
  spad_process_list = NULL;
}

@
\subsection{print\_spad\_process\_list}
<<printspadprocesslist>>=
#if 0
static void
print_spad_process_list()
{
  SpadProcess *proc;
  for(proc = spad_process_list; proc != NULL; proc = proc->next)
    fprintf(stderr, "proc_id = %d, death_action = %d\n", proc->proc_id,
	    proc->death_action);
}
#endif

@
\subsection{find\_child}
<<findchild>>=
static SpadProcess *
find_child(int proc_id)
{
  SpadProcess *proc;
  for(proc = spad_process_list; proc != NULL; proc = proc->next)
    if (proc->proc_id == proc_id) return proc;
  return NULL;
}

@
\subsection{kill\_all\_children}
<<killallchildren>>=
static void
kill_all_children(void)
{
  char name[256];
  SpadProcess *proc;
  
  
  for(proc = spad_process_list; proc != NULL; proc = proc->next) {
    kill(proc->proc_id, SIGTERM);
  }
  sprintf(name, "/tmp/hyper%d.input",server_num);
  unlink(name);

}

@
\subsection{clean\_up\_terminal}
<<cleanupterminal>>=
static void
clean_up_terminal(void)
{
  tcsetattr(0, TCSAFLUSH, &oldbuf);
}

@
\subsection{monitor\_children}
<<monitorchildren>>=
static void
monitor_children(void)
{
  int dead_baby, stat;
  SpadProcess *proc;
  while (1) {
    stat = 0;
    dead_baby = wait(&stat);
    /* Check the value of dead_baby, since wait may have returned
       a pid but subsequently we have received a signal.  Yeuch! */
    if (dead_baby == -1 && death_signal) {
      kill_all_children();
      clean_up_sockets();
      sleep(2);
      exit(0);
    }
    /* Check the value of dead_baby, since wait may have returned
       a pid but subsequently we have received a signal.  Yeuch! */
    if(dead_baby == -1 && nagman_signal) {
      nagman_signal=0;
      spawn_of_hell(NagManagerProgram,NadaDelShitsky);
      continue;
    }

    if (dead_baby == -1) {
      fprintf(stderr, "sman: wait returned -1\n");
      continue;
    }
    proc = find_child(dead_baby);
    if (proc == NULL) {
      /*      fprintf(stderr, "sman: %d is not known to be a child process\n",
	      dead_baby);
	      */
      continue;
    }
    switch(proc->death_action) {
    case Die:
      kill_all_children();
      clean_up_sockets();
      sleep(2);
      exit(0);
    case NadaDelShitsky:
      break;
    case DoItAgain:
      spawn_of_hell(proc->command, DoItAgain);
      break;
    case CleanHypertexSocket:
      clean_hypertex_socket();
      break;
    }
  }
}

@
\subsection{main}
The main procedure should return an [[int]]. We change the return value
here and in [[src/include/sman.H1]].
<<result>>=
  return(0);
@
<<main>>=
int
main(int argc, char *argv[],char *envp[])
{
  if (tpd == 1) fprintf(stderr,"sman:main entered\n");
  bsdSignal(SIGINT,  SIG_IGN,RestartSystemCalls);
  process_options(argc, argv);

  init_term_io();
  init_spad_process_list();
  start_the_Axiom(envp);
  if (open_server(SessionIOName) == -2) {
    fprintf(stderr, "Fatal error opening I/O socket\n");
    clean_up_sockets();
    exit(-1);
  }
  start_the_session_manager();
  if (start_spadclient)       start_the_spadclient();
  if (start_local_spadclient) start_the_local_spadclient();
  if (start_nagman)           start_the_nagman();
  if (start_ht)               start_the_hypertex();
  if (start_graphics)         start_the_graphics();
  sleep(1);

  if (fork_you(Die) != NULL) {
    sman_catch_signals();
    monitor_children();
    exit(0);
  }
  manage_spad_io(ptcNum);
  if (tpd == 1) fprintf(stderr,"sman:main exit\n");
<<result>>
}

@
\subsection{sman}
<<sman>>=
#define _SMAN_C

<<includes>>
<<variables>>
<<processarguments>>
<<shouldIclef>>
<<inX>>
<<setupdefaults>>
<<processoptions>>
<<deathhandler>>
<<nagmanhandler>>
<<smancatchsignals>>
<<fixenv>>
<<inittermio>>
<<strPrefix>>
<<checkspadproc>>
<<cleanupoldsockets>>
<<forkyou>>
<<execcommandenv>>
<<spawnofhell>>
<<startthespadclient>>
<<startthelocalspadclient>>
<<startthenagman>>
<<startthesessionmanager>>
<<startthehypertex>>
<<startthegraphics>>
<<forkAxiom>>
<<starttheAxiom>>
<<cleanupsockets>>
<<readfromspadio>>
<<readfrommanager>>
<<managespadio>>
<<initspadprocesslist>>
<<printspadprocesslist>>
<<findchild>>
<<killallchildren>>
<<cleanupterminal>>
<<monitorchildren>>
<<main>>

@
\section{License}
<<license>>=
/*
Copyright (c) 1991-2002, The Numerical ALgorithms Group Ltd.
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

    - Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.

    - Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in
      the documentation and/or other materials provided with the
      distribution.

    - Neither the name of The Numerical ALgorithms Group Ltd. nor the
      names of its contributors may be used to endorse or promote products
      derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

@
<<*>>=
<<license>>
<<sman>>
@ 
\eject
\begin{thebibliography}{99}
\bibitem{1} nothing
\end{thebibliography}
\end{document}