games/hack/hack.pager.c

   1 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
   2 /* hack.pager.c - version 1.0.3 */
   3 /* $FreeBSD: src/games/hack/hack.pager.c,v 1.7 1999/11/16 02:57:09 billf Exp $ */
   4
   5 /* This file contains the command routine dowhatis() and a pager. */
   6 /*
   7  * Also readmail() and doshell(), and generally the things that contact the
   8  * outside world.
   9  */
  10
  11 #include <sys/types.h>
  12 #include <signal.h>
  13 #include "hack.h"
  14 extern int CO, LI;      /* usually COLNO and ROWNO+2 */
  15 extern char *CD;
  16 extern char quitchars[];
  17
  18 static void intruph(int);
  19 static void page_more(FILE *, int);
  20
  21 int
  22 dowhatis(void)
  23 {
  24         FILE *fp;
  25         char bufr[BUFSZ + 6];
  26         char *buf = &bufr[6], *ep, q;
  27
  28         if (!(fp = fopen(DATAFILE, "r")))
  29                 pline("Cannot open data file!");
  30         else {
  31                 pline("Specify what? ");
  32                 q = readchar();
  33                 if (q != '\t')
  34                         while (fgets(buf, BUFSZ, fp))
  35                                 if (*buf == q) {
  36                                         ep = strchr(buf, '\n');
  37                                         if (ep)
  38                                                 *ep = 0;
  39                                         /* else: bad data file */
  40                                         /* Expand tab 'by hand' */
  41                                         if (buf[1] == '\t') {
  42                                                 buf = bufr;
  43                                                 buf[0] = q;
  44                                                 memcpy(buf + 1, "       ", 7);
  45                                         }
  46                                         pline("%s", buf);
  47                                         if (ep[-1] == ';') {
  48                                                 pline("More info? ");
  49                                                 if (readchar() == 'y') {
  50                                                         page_more(fp, 1); /* does fclose() */
  51                                                         return (0);
  52                                                 }
  53                                         }
  54                                         fclose(fp);     /* kopper@psuvax1 */
  55                                         return (0);
  56                                 }
  57                 pline("I've never heard of such things.");
  58                 fclose(fp);
  59         }
  60         return (0);
  61 }
  62
  63 /* make the paging of a file interruptible */
  64 static int got_intrup;
  65
  66 static void
  67 intruph(int unused __unused)
  68 {
  69         got_intrup++;
  70 }
  71
  72 /* simple pager, also used from dohelp() */
  73 /* strip: nr of chars to be stripped from each line (0 or 1) */
  74 static void
  75 page_more(FILE *fp, int strip)
  76 {
  77         char *bufr, *ep;
  78         sig_t prevsig = signal(SIGINT, intruph);
  79
  80         set_pager(0);
  81         bufr = alloc((unsigned)CO);
  82         bufr[CO - 1] = 0;
  83         while (fgets(bufr, CO - 1, fp) && (!strip || *bufr == '\t') && !got_intrup) {
  84                 ep = strchr(bufr, '\n');
  85                 if (ep)
  86                         *ep = 0;
  87                 if (page_line(bufr + strip)) {
  88                         set_pager(2);
  89                         goto ret;
  90                 }
  91         }
  92         set_pager(1);
  93 ret:
  94         free(bufr);
  95         fclose(fp);
  96         signal(SIGINT, prevsig);
  97         got_intrup = 0;
  98 }
  99
 100 static boolean whole_screen = TRUE;
 101 #define PAGMIN  12      /* minimum # of lines for page below level map */
 102
 103 void
 104 set_whole_screen(void)  /* called in termcap as soon as LI is known */
 105 {
 106         whole_screen = (LI - ROWNO - 2 <= PAGMIN || !CD);
 107 }
 108
 109 #ifdef NEWS
 110 bool
 111 readnews(void)
 112 {
 113         int ret;
 114
 115         whole_screen = TRUE;    /* force a docrt(), our first */
 116         ret = page_file(NEWS, TRUE);
 117         set_whole_screen();
 118         return (ret);           /* report whether we did docrt() */
 119 }
 120 #endif /* NEWS */
 121
 122 void
 123 set_pager(int mode)             /* 0: open  1: wait+close  2: close */
 124 {
 125         static boolean so;
 126
 127         if (mode == 0) {
 128                 if (!whole_screen) {
 129                         /* clear topline */
 130                         clrlin();
 131                         /* use part of screen below level map */
 132                         curs(1, ROWNO + 4);
 133                 } else {
 134                         cls();
 135                 }
 136                 so = flags.standout;
 137                 flags.standout = 1;
 138         } else {
 139                 if (mode == 1) {
 140                         curs(1, LI);
 141                         more();
 142                 }
 143                 flags.standout = so;
 144                 if (whole_screen)
 145                         docrt();
 146                 else {
 147                         curs(1, ROWNO + 4);
 148                         cl_eos();
 149                 }
 150         }
 151 }
 152
 153 bool
 154 page_line(const char *s)        /* returns 1 if we should quit */
 155 {
 156         if (cury == LI - 1) {
 157                 if (!*s)
 158                         return (0);     /* suppress blank lines at top */
 159                 putchar('\n');
 160                 cury++;
 161                 cmore("q\033");
 162                 if (morc) {
 163                         morc = 0;
 164                         return (1);
 165                 }
 166                 if (whole_screen)
 167                         cls();
 168                 else {
 169                         curs(1, ROWNO + 4);
 170                         cl_eos();
 171                 }
 172         }
 173         puts(s);
 174         cury++;
 175         return (0);
 176 }
 177
 178 /*
 179  * Flexible pager: feed it with a number of lines and it will decide
 180  * whether these should be fed to the pager above, or displayed in a
 181  * corner.
 182  * Call:
 183  *      cornline(0, title or 0) : initialize
 184  *      cornline(1, text)       : add text to the chain of texts
 185  *      cornline(2, morcs)      : output everything and cleanup
 186  *      cornline(3, 0)          : cleanup
 187  */
 188
 189 void
 190 cornline(int mode, const char *text)
 191 {
 192         static struct line {
 193                 struct line *next_line;
 194                 char *line_text;
 195         } *texthead, *texttail;
 196         static int maxlen;
 197         static int linect;
 198         struct line *tl;
 199
 200         if (mode == 0) {
 201                 texthead = NULL;
 202                 maxlen = 0;
 203                 linect = 0;
 204                 if (text) {
 205                         cornline(1, text);      /* title */
 206                         cornline(1, "");        /* blank line */
 207                 }
 208                 return;
 209         }
 210
 211         if (mode == 1) {
 212                 int len;
 213
 214                 if (!text)      /* superfluous, just to be sure */
 215                         return;
 216                 linect++;
 217                 len = strlen(text);
 218                 if (len > maxlen)
 219                         maxlen = len;
 220                 tl = alloc((unsigned)(len + sizeof(struct line) + 1));
 221                 tl->next_line = NULL;
 222                 tl->line_text = (char *)(tl + 1);
 223                 strcpy(tl->line_text, text);
 224                 if (!texthead)
 225                         texthead = tl;
 226                 else
 227                         texttail->next_line = tl;
 228                 texttail = tl;
 229                 return;
 230         }
 231
 232         /* --- now we really do it --- */
 233         if (mode == 2 && linect == 1)   /* topline only */
 234                 pline("%s", texthead->line_text);
 235         else if (mode == 2) {
 236                 int curline, lth;
 237
 238                 if (flags.toplin == 1)  /* ab@unido */
 239                         more();
 240                 remember_topl();
 241
 242                 lth = CO - maxlen - 2;          /* Use full screen width */
 243                 if (linect < LI && lth >= 10) { /* in a corner */
 244                         home();
 245                         cl_end();
 246                         flags.toplin = 0;
 247                         curline = 1;
 248                         for (tl = texthead; tl; tl = tl->next_line) {
 249                                 curs(lth, curline);
 250                                 if (curline > 1)
 251                                         cl_end();
 252                                 putsym(' ');
 253                                 putstr(tl->line_text);
 254                                 curline++;
 255                         }
 256                         curs(lth, curline);
 257                         cl_end();
 258                         cmore(text);
 259                         home();
 260                         cl_end();
 261                         docorner(lth, curline - 1);
 262                 } else {                /* feed to pager */
 263                         set_pager(0);
 264                         for (tl = texthead; tl; tl = tl->next_line) {
 265                                 if (page_line(tl->line_text)) {
 266                                         set_pager(2);
 267                                         goto cleanup;
 268                                 }
 269                         }
 270                         if (text) {
 271                                 cgetret(text);
 272                                 set_pager(2);
 273                         } else
 274                                 set_pager(1);
 275                 }
 276         }
 277
 278 cleanup:
 279         while ((tl = texthead) != NULL) {
 280                 texthead = tl->next_line;
 281                 free(tl);
 282         }
 283 }
 284
 285 int
 286 dohelp(void)
 287 {
 288         char c;
 289
 290         pline("Long or short help? ");
 291         while (((c = readchar()) != 'l') && (c != 's') && !strchr(quitchars, c))
 292                 bell();
 293         if (!strchr(quitchars, c))
 294                 page_file((c == 'l') ? HELP : SHELP, FALSE);
 295         return (0);
 296 }
 297
 298 /* return: 0 - cannot open fnam; 1 - otherwise */
 299 bool
 300 page_file(const char *fnam, bool silent)
 301 {
 302 #ifdef DEF_PAGER                /* this implies that UNIX is defined */
 303         /* use external pager; this may give security problems */
 304         int fd = open(fnam, O_RDONLY);
 305
 306         if (fd < 0) {
 307                 if (!silent)
 308                         pline("Cannot open %s.", fnam);
 309                 return (0);
 310         }
 311         if (child(1)) {
 312                 extern char *catmore;
 313
 314                 /*
 315                  * Now that child() does a setuid(getuid()) and a
 316                  * chdir(), we may not be able to open file fnam
 317                  * anymore, so make it stdin.
 318                  */
 319                 close(0);
 320                 if (dup(fd)) {
 321                         if (!silent)
 322                                 printf("Cannot open %s as stdin.\n", fnam);
 323                 } else {
 324                         execl(catmore, "page", NULL);
 325                         if (!silent)
 326                                 printf("Cannot exec %s.\n", catmore);
 327                 }
 328                 exit(1);
 329         }
 330         close(fd);
 331 #else /* DEF_PAGER */
 332         FILE *f;                /* free after Robert Viduya */
 333
 334         if ((f = fopen(fnam, "r")) == NULL) {
 335                 if (!silent) {
 336                         home();
 337                         perror(fnam);
 338                         flags.toplin = 1;
 339                         pline("Cannot open %s.", fnam);
 340                 }
 341                 return (0);
 342         }
 343         page_more(f, 0);
 344 #endif /* DEF_PAGER */
 345
 346         return (1);
 347 }
 348
 349 #ifdef UNIX
 350 #ifdef SHELL
 351 int
 352 dosh(void)
 353 {
 354         char *str;
 355
 356         if (child(0)) {
 357                 if ((str = getenv("SHELL")) != NULL)
 358                         execl(str, str, NULL);
 359                 else
 360                         execl("/bin/sh", "sh", NULL);
 361                 pline("sh: cannot execute.");
 362                 exit(1);
 363         }
 364         return (0);
 365 }
 366 #endif /* SHELL */
 367
 368 #ifdef NOWAITINCLUDE
 369 union wait {                    /* used only for the cast  (union wait *)0 */
 370         int w_status;
 371         struct {
 372                 unsigned short w_Termsig:7;
 373                 unsigned short w_Coredump:1;
 374                 unsigned short w_Retcode:8;
 375         } w_T;
 376 };
 377
 378 #else
 379 #include        <sys/wait.h>
 380 #endif /* NOWAITINCLUDE */
 381
 382 bool
 383 child(bool wt)
 384 {
 385         int status;
 386         int f;
 387
 388         f = fork();
 389         if (f == 0) {           /* child */
 390                 settty(NULL);   /* also calls end_screen() */
 391                 /* revoke */
 392                 setgid(getgid());
 393 #ifdef CHDIR
 394                 chdir(getenv("HOME"));
 395 #endif /* CHDIR */
 396                 return (1);
 397         }
 398         if (f == -1) {          /* cannot fork */
 399                 pline("Fork failed. Try again.");
 400                 return (0);
 401         }
 402         /* fork succeeded; wait for child to exit */
 403         signal(SIGINT, SIG_IGN);
 404         signal(SIGQUIT, SIG_IGN);
 405         wait(&status);
 406         gettty();
 407         setftty();
 408         signal(SIGINT, done1);
 409 #ifdef WIZARD
 410         if (wizard)
 411                 signal(SIGQUIT, SIG_DFL);
 412 #endif /* WIZARD */
 413         if (wt)
 414                 getret();
 415         docrt();
 416         return (0);
 417 }
 418 #endif /* UNIX */