commands/yap/help.c

   1 /* Copyright (c) 1985 Ceriel J.H. Jacobs */
   2
   3 #ifndef lint
   4 static char rcsid[] = "$Header$";
   5 #endif
   6
   7 #define _HELP_
   8 #include "in_all.h"
   9 #include "help.h"
  10 #include "machine.h"
  11 #include "commands.h"
  12 #include "keys.h"
  13 #include "output.h"
  14 #include "prompt.h"
  15 #include "main.h"
  16 #include "display.h"
  17 #include "term.h"
  18 #include "options.h"
  19
  20 static int h_cnt;               /* Count # of lines */
  21 static struct state *origin;    /* Keep track of startstate */
  22
  23 /*
  24  * Print a key sequence.
  25  * We arrived at an endstate. The s_next link in the state structure now
  26  * leads us from "origin" to the current state, so that we can print the key
  27  * sequence easily.
  28  */
  29
  30 STATIC VOID
  31 pr_comm() {
  32         register struct state *p = origin;
  33         register char *pb;
  34         register int c;
  35         char buf[30];
  36         register int i = 0;     /* How many characters printed? */
  37
  38         pb = buf;
  39         for (;;) {
  40                 c = p->s_char & 0177;
  41                 if (c < ' ' || c == 0177) {
  42                         /*
  43                          * Will take an extra position
  44                          */
  45                         i++;
  46                 }
  47                 *pb++ = c;
  48                 i++;
  49                 if (!p->s_match) break;
  50                 p = p->s_next;
  51         }
  52         do {
  53                 *pb++ = ' ';
  54         } while (++i < 12);
  55         *pb = 0;
  56         cputline(buf);
  57 }
  58
  59 /*
  60  * Print out a description of the keymap. This is done, by temporarily using
  61  * the s_next field in the state structure indicate the state matching the
  62  * next character, so that we can walk from "origin" to an endstate.
  63  */
  64
  65 STATIC VOID
  66 pr_mach(currstate, back) register struct state *currstate, *back; {
  67         struct state *save;
  68
  69         while (currstate) {
  70                 if (interrupt) break;
  71                 if (back) {
  72                         save = back->s_next;    /* Save original link */
  73                         back->s_next = currstate;
  74                 }
  75                 if (!currstate->s_match) {
  76                         /*
  77                          * End state, print command
  78                          */
  79                         pr_comm();
  80                         putline(commands[currstate->s_cnt].c_descr);
  81                         putline("\r\n");
  82                         if (++h_cnt >= maxpagesize) {
  83                                 ret_to_continue();
  84                                 h_cnt = 0;
  85                         }
  86                 }
  87                 else pr_mach(currstate->s_match, currstate);
  88                 currstate = currstate->s_next;
  89                 if (back) back->s_next = save;  /* restore */
  90                 else origin = currstate;
  91         }
  92 }
  93
  94 /*ARGSUSED*/
  95 int
  96 do_help(i) long i; {    /* The help command */
  97
  98         startcomm = 0;
  99         h_cnt = 2;
 100         putline("\r\nSummary of yap commands:\r\n");
 101         origin = currmap->k_mach;
 102         pr_mach(currmap->k_mach, (struct state *) 0);
 103         if (h_cnt) {
 104                 ret_to_continue();
 105         }
 106         if (!hardcopy && scr_info.currentpos) redraw(1);
 107 }