interface.c

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#include "standard.h"
#include "interface.h"
#include <sys/types.h>
#include <sys/time.h>

/*#define DEBUG*/
#define STRLEN 256

static char line[STRLEN];
static char lastline[STRLEN];
static char cmd[STRLEN];
static char arg[STRLEN];
static int breakpoint = 0;
static int stop = 0;
static enum { Prompt, Run, Cont, Next, Quit } mode;

extern int Quit_Mux;
extern int debug;

static void prompt(void)
{
  printf("mux_sim:%d [%s]> ", get_clock(), lastline);
  fflush(stdout);
}

static void get_input(void)
{
  fgets(line, STRLEN, stdin);
  if (strlen(line)) {
    line[strlen(line)-1]='\0';
  }
#ifdef DEBUG
  printf("line=\"%s\"\n", line);
#endif  
}

static int white(char c)
{
  return ((c == ' ') || (c == '\t'));
}

static void parse_input(void)
{
  int i=0,j=0,k=0;

  if ((line[0]=='\0') && (lastline[0]!='\0'))
    strcpy(line, lastline);
  else
    strcpy(lastline, line);
  
  cmd[0]='\0';
  arg[0]='\0';

  if (strlen(line)) {
    while (white(line[i]))
      i++;
    while ((!white(line[i])) && (line[i]!='\0'))
      cmd[j++]=line[i++];
    cmd[j]='\0';
    while (white(line[i]))
      i++;
    while (line[i]!='\0')
      arg[k++]=line[i++];
    arg[k]='\0';
#ifdef DEBUG
    printf("cmd=\"%s\", arg=\"%s\"\n", cmd, arg);
#endif
  }
}

static int equals(char *s1, char *s2)
{
  return (strcmp(s1,s2)==0);
}



static void show_vars()
{
  printf("Variables:\n");
  printf("\tdebug = %d\n", debug);
}


static char *rank(int x)
{
  if (x >= 250)
    return (" Master MUXer");
  if (x >= 200)
    return (" MUX Engineer");
  if (x >= 150)
    return ("n ITU LBC Expert");
  if (x >= 100)
    return ("n ITU Technical Writer");  
  return(" Novice Adventurer");  
}


static void show_score(void)
{
  static int first = 1;
  int x;
  if (first) {
    time_t tloc;
    srand((int) time(&tloc));
    first=0;
  }
  x = rand() % 256;
  printf("Your score is %d points, which ranks you as a%s\n", x, rank(x));
}

static void print_commands(void)
{
  printf("\nAvailable Commands:\n\n");
  printf("b <x>   = break when clock = x\n");
  printf("c       = continue until breakpoint\n");
  printf("d <l>   = set debug = l\n");
  printf("n <i>   = continue for i clock cycles\n");
  printf("r       = run continuously\n");
  printf("q       = quit\n");
  printf("\n");
}


static void do_cmd(void)
{
  char s[STRLEN];
  if (equals(cmd, "score")) {
    show_score();
  } 
  else if (equals(cmd, "xyzzy")) {
    if (debug)
      printf("Poof!\n");
    else
      printf("Nothing happens.\n"); 
  } 
  else if (equals(cmd, "clear")) {
    clrscr();
  } 
  else if (equals(cmd, "?")||equals(cmd, "h")||equals(cmd, "help")) {
    print_commands();
  } 
  else if (equals(cmd, "q")) {
    Quit_Mux = 1;
    mode = Quit;
  } 
  else if (equals(cmd, "quit")) {
    Quit_Mux = 1;
    mode = Quit;
  } 
  else if (equals(cmd, "set")) {
    show_vars();
  }
  else if (equals(cmd, "c")) {
    mode = Cont;
  } 
  else if (equals(cmd, "d")) {
    debug = atoi(arg);
    printf("debug set to %d\n", debug);
  }
  else if (equals(cmd, "b")) {
    if (arg[0]!='\0') {
      breakpoint = atoi(arg);
      printf("New breakpoint at clock=%d\n", breakpoint);
    } else {
      printf("Breakpoint not changed.\n");
    }
  } 
  else if (equals(cmd, "n")) {
    if (stop=atoi(arg))
      stop += get_clock();
    else
      stop += get_clock() + 1;
    mode = Next;
  }
}


void interface(void)
{
  switch (mode) {
    case Prompt: break;
    case Run:    break;
    case Cont:   
                 if (get_clock() == breakpoint)
                   mode = Prompt;
                 break;
    case Next:
                 if (get_clock() == stop)
                   mode = Prompt;
                 break;
    case Quit: 
                 break;
    default:
                error("interface","invalid mode");
  }

  while (mode == Prompt) {
    prompt();
    get_input();
    parse_input();
    do_cmd();
  }
}

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