cl/cl_read.c

   1 /*-
   2  * Copyright (c) 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  * Copyright (c) 1993, 1994, 1995, 1996
   5  *      Keith Bostic.  All rights reserved.
   6  *
   7  * See the LICENSE file for redistribution information.
   8  */
   9
  10 #include "config.h"
  11
  12 #ifndef lint
  13 static const char sccsid[] = "$Id: cl_read.c,v 10.19 2000/07/15 20:26:33 skimo Exp $ (Berkeley) $Date: 2000/07/15 20:26:33 $";
  14 #endif /* not lint */
  15
  16 #include <sys/types.h>
  17 #include <sys/queue.h>
  18 #ifdef HAVE_SYS_SELECT_H
  19 #include <sys/select.h>
  20 #endif
  21 #include <sys/time.h>
  22
  23 #include <bitstring.h>
  24 #include <curses.h>
  25 #include <errno.h>
  26 #include <fcntl.h>
  27 #include <signal.h>
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <termios.h>
  32 #include <unistd.h>
  33
  34 #include "../common/common.h"
  35 #include "../ex/script.h"
  36 #include "cl.h"
  37
  38 static input_t  cl_read __P((SCR *,
  39     u_int32_t, char *, size_t, int *, struct timeval *));
  40 static int      cl_resize __P((SCR *, size_t, size_t));
  41
  42 /*
  43  * cl_event --
  44  *      Return a single event.
  45  *
  46  * PUBLIC: int cl_event __P((SCR *, EVENT *, u_int32_t, int));
  47  */
  48 int
  49 cl_event(sp, evp, flags, ms)
  50         SCR *sp;
  51         EVENT *evp;
  52         u_int32_t flags;
  53         int ms;
  54 {
  55         struct timeval t, *tp;
  56         CL_PRIVATE *clp;
  57         size_t lines, columns;
  58         int changed, nr;
  59         CHAR_T *wp;
  60         size_t wlen;
  61
  62         /*
  63          * Queue signal based events.  We never clear SIGHUP or SIGTERM events,
  64          * so that we just keep returning them until the editor dies.
  65          */
  66         clp = CLP(sp);
  67 retest: if (LF_ISSET(EC_INTERRUPT) || F_ISSET(clp, CL_SIGINT)) {
  68                 if (F_ISSET(clp, CL_SIGINT)) {
  69                         F_CLR(clp, CL_SIGINT);
  70                         evp->e_event = E_INTERRUPT;
  71                 } else
  72                         evp->e_event = E_TIMEOUT;
  73                 return (0);
  74         }
  75         if (F_ISSET(clp, CL_SIGHUP | CL_SIGTERM | CL_SIGWINCH)) {
  76                 if (F_ISSET(clp, CL_SIGHUP)) {
  77                         evp->e_event = E_SIGHUP;
  78                         return (0);
  79                 }
  80                 if (F_ISSET(clp, CL_SIGTERM)) {
  81                         evp->e_event = E_SIGTERM;
  82                         return (0);
  83                 }
  84                 if (F_ISSET(clp, CL_SIGWINCH)) {
  85                         F_CLR(clp, CL_SIGWINCH);
  86                         if (cl_ssize(sp, 1, &lines, &columns, &changed))
  87                                 return (1);
  88                         if (changed) {
  89                                 (void)cl_resize(sp, lines, columns);
  90                                 evp->e_event = E_WRESIZE;
  91                                 return (0);
  92                         }
  93                         /* No real change, ignore the signal. */
  94                 }
  95         }
  96
  97         /* Set timer. */
  98         if (ms == 0)
  99                 tp = NULL;
 100         else {
 101                 t.tv_sec = ms / 1000;
 102                 t.tv_usec = (ms % 1000) * 1000;
 103                 tp = &t;
 104         }
 105
 106         /* Read input characters. */
 107         switch (cl_read(sp, LF_ISSET(EC_QUOTED | EC_RAW),
 108             (char *)clp->ibuf, sizeof(clp->ibuf)/sizeof(CHAR_T), &nr, tp)) {
 109         case INP_OK:
 110                 CHAR2INT(sp, (char *)clp->ibuf, nr, wp, wlen);
 111                 MEMMOVEW(clp->ibuf, wp, wlen);
 112                 evp->e_csp = clp->ibuf;
 113                 evp->e_len = wlen;
 114                 evp->e_event = E_STRING;
 115                 break;
 116         case INP_EOF:
 117                 evp->e_event = E_EOF;
 118                 break;
 119         case INP_ERR:
 120                 evp->e_event = E_ERR;
 121                 break;
 122         case INP_INTR:
 123                 goto retest;
 124         case INP_TIMEOUT:
 125                 evp->e_event = E_TIMEOUT;
 126                 break;
 127         default:
 128                 abort();
 129         }
 130         return (0);
 131 }
 132
 133 /*
 134  * cl_read --
 135  *      Read characters from the input.
 136  */
 137 static input_t
 138 cl_read(sp, flags, bp, blen, nrp, tp)
 139         SCR *sp;
 140         u_int32_t flags;
 141         char *bp;
 142         size_t blen;
 143         int *nrp;
 144         struct timeval *tp;
 145 {
 146         struct termios term1, term2;
 147         struct timeval poll;
 148         CL_PRIVATE *clp;
 149         GS *gp;
 150         SCR *tsp;
 151         fd_set rdfd;
 152         input_t rval;
 153         int maxfd, nr, term_reset;
 154
 155         gp = sp->gp;
 156         clp = CLP(sp);
 157         term_reset = 0;
 158
 159         /*
 160          * 1: A read from a file or a pipe.  In this case, the reads
 161          *    never timeout regardless.  This means that we can hang
 162          *    when trying to complete a map, but we're going to hang
 163          *    on the next read anyway.
 164          */
 165         if (!F_ISSET(clp, CL_STDIN_TTY)) {
 166                 switch (nr = read(STDIN_FILENO, bp, blen)) {
 167                 case 0:
 168                         return (INP_EOF);
 169                 case -1:
 170                         goto err;
 171                 default:
 172                         *nrp = nr;
 173                         return (INP_OK);
 174                 }
 175                 /* NOTREACHED */
 176         }
 177
 178         /*
 179          * 2: A read with an associated timeout, e.g., trying to complete
 180          *    a map sequence.  If input exists, we fall into #3.
 181          */
 182         FD_ZERO(&rdfd);
 183         poll.tv_sec = 0;
 184         poll.tv_usec = 0;
 185         if (tp != NULL) {
 186                 FD_SET(STDIN_FILENO, &rdfd);
 187                 switch (select(STDIN_FILENO + 1,
 188                     &rdfd, NULL, NULL, tp == NULL ? &poll : tp)) {
 189                 case 0:
 190                         return (INP_TIMEOUT);
 191                 case -1:
 192                         goto err;
 193                 default:
 194                         break;
 195                 }
 196         }
 197
 198         /*
 199          * The user can enter a key in the editor to quote a character.  If we
 200          * get here and the next key is supposed to be quoted, do what we can.
 201          * Reset the tty so that the user can enter a ^C, ^Q, ^S.  There's an
 202          * obvious race here, when the key has already been entered, but there's
 203          * nothing that we can do to fix that problem.
 204          *
 205          * The editor can ask for the next literal character even thought it's
 206          * generally running in line-at-a-time mode.  Do what we can.
 207          */
 208         if (LF_ISSET(EC_QUOTED | EC_RAW) && !tcgetattr(STDIN_FILENO, &term1)) {
 209                 term_reset = 1;
 210                 if (LF_ISSET(EC_QUOTED)) {
 211                         term2 = term1;
 212                         term2.c_lflag &= ~ISIG;
 213                         term2.c_iflag &= ~(IXON | IXOFF);
 214                         (void)tcsetattr(STDIN_FILENO,
 215                             TCSASOFT | TCSADRAIN, &term2);
 216                 } else
 217                         (void)tcsetattr(STDIN_FILENO,
 218                             TCSASOFT | TCSADRAIN, &clp->vi_enter);
 219         }
 220
 221         /*
 222          * 3: Wait for input.
 223          *
 224          * Select on the command input and scripting window file descriptors.
 225          * It's ugly that we wait on scripting file descriptors here, but it's
 226          * the only way to keep from locking out scripting windows.
 227          */
 228         if (F_ISSET(gp, G_SCRWIN)) {
 229                 FD_ZERO(&rdfd);
 230                 FD_SET(STDIN_FILENO, &rdfd);
 231                 maxfd = STDIN_FILENO;
 232                 if (sscr_check_input(sp, &rdfd, maxfd))
 233                         goto err;
 234         }
 235
 236         /*
 237          * 4: Read the input.
 238          *
 239          * !!!
 240          * What's going on here is some scary stuff.  Ex runs the terminal in
 241          * canonical mode.  So, the <newline> character terminating a line of
 242          * input is returned in the buffer, but a trailing <EOF> character is
 243          * not similarly included.  As ex uses 0<EOF> and ^<EOF> as autoindent
 244          * commands, it has to see the trailing <EOF> characters to determine
 245          * the difference between the user entering "0ab" and "0<EOF>ab".  We
 246          * leave an extra slot in the buffer, so that we can add a trailing
 247          * <EOF> character if the buffer isn't terminated by a <newline>.  We
 248          * lose if the buffer is too small for the line and exactly N characters
 249          * are entered followed by an <EOF> character.
 250          */
 251 #define ONE_FOR_EOF     1
 252         switch (nr = read(STDIN_FILENO, bp, blen - ONE_FOR_EOF)) {
 253         case  0:                                /* EOF. */
 254                 /*
 255                  * ^D in canonical mode returns a read of 0, i.e. EOF.  EOF is
 256                  * a valid command, but we don't want to loop forever because
 257                  * the terminal driver is returning EOF because the user has
 258                  * disconnected. The editor will almost certainly try to write
 259                  * something before this fires, which should kill us, but You
 260                  * Never Know.
 261                  */
 262                 if (++clp->eof_count < 50) {
 263                         bp[0] = clp->orig.c_cc[VEOF];
 264                         *nrp = 1;
 265                         rval = INP_OK;
 266
 267                 } else
 268                         rval = INP_EOF;
 269                 break;
 270         case -1:                                /* Error or interrupt. */
 271 err:            if (errno == EINTR)
 272                         rval = INP_INTR;
 273                 else {
 274                         rval = INP_ERR;
 275                         msgq(sp, M_SYSERR, "input");
 276                 }
 277                 break;
 278         default:                                /* Input characters. */
 279                 if (F_ISSET(sp, SC_EX) && bp[nr - 1] != '\n')
 280                         bp[nr++] = clp->orig.c_cc[VEOF];
 281                 *nrp = nr;
 282                 clp->eof_count = 0;
 283                 rval = INP_OK;
 284                 break;
 285         }
 286
 287         /* Restore the terminal state if it was modified. */
 288         if (term_reset)
 289                 (void)tcsetattr(STDIN_FILENO, TCSASOFT | TCSADRAIN, &term1);
 290         return (rval);
 291 }
 292
 293 /*
 294  * cl_resize --
 295  *      Reset the options for a resize event.
 296  */
 297 static int
 298 cl_resize(sp, lines, columns)
 299         SCR *sp;
 300         size_t lines, columns;
 301 {
 302         int rval;
 303
 304         rval = api_opts_set(sp, "lines", NULL, lines, 0);
 305         if (api_opts_set(sp, "columns", NULL, columns, 0))
 306                 rval = 1;
 307         return (rval);
 308 }