dist/nvi/cl/cl_read.c

   1 /*      $NetBSD: cl_read.c,v 1.1.1.2 2008/05/18 14:29:37 aymeric Exp $ */
   2
   3 /*-
   4  * Copyright (c) 1993, 1994
   5  *      The Regents of the University of California.  All rights reserved.
   6  * Copyright (c) 1993, 1994, 1995, 1996
   7  *      Keith Bostic.  All rights reserved.
   8  *
   9  * See the LICENSE file for redistribution information.
  10  */
  11
  12 #include "config.h"
  13
  14 #ifndef lint
  15 static const char sccsid[] = "Id: cl_read.c,v 10.29 2001/08/18 21:51:59 skimo Exp (Berkeley) Date: 2001/08/18 21:51:59";
  16 #endif /* not lint */
  17
  18 #include <sys/types.h>
  19 #include <sys/queue.h>
  20 #ifdef HAVE_SYS_SELECT_H
  21 #include <sys/select.h>
  22 #endif
  23 #include <sys/time.h>
  24
  25 #include <bitstring.h>
  26 #include <errno.h>
  27 #include <fcntl.h>
  28 #include <signal.h>
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <termios.h>
  33 #include <unistd.h>
  34
  35 #include "../common/common.h"
  36 #include "../ex/script.h"
  37 #include "cl.h"
  38
  39 /* Pollution by Solaris curses. */
  40 #undef columns
  41 #undef lines
  42
  43 static input_t  cl_read __P((SCR *,
  44     u_int32_t, char *, size_t, int *, struct timeval *));
  45 static int      cl_resize __P((SCR *, size_t, size_t));
  46
  47 /*
  48  * cl_event --
  49  *      Return a single event.
  50  *
  51  * PUBLIC: int cl_event __P((SCR *, EVENT *, u_int32_t, int));
  52  */
  53 int
  54 cl_event(SCR *sp, EVENT *evp, u_int32_t flags, int ms)
  55 {
  56         struct timeval t, *tp;
  57         CL_PRIVATE *clp;
  58         size_t lines, columns;
  59         int changed, nr = 0;
  60         const CHAR_T *wp;
  61         size_t wlen;
  62         int rc;
  63
  64         /*
  65          * Queue signal based events.  We never clear SIGHUP or SIGTERM events,
  66          * so that we just keep returning them until the editor dies.
  67          */
  68         clp = CLP(sp);
  69 retest: if (LF_ISSET(EC_INTERRUPT) || F_ISSET(clp, CL_SIGINT)) {
  70                 if (F_ISSET(clp, CL_SIGINT)) {
  71                         F_CLR(clp, CL_SIGINT);
  72                         evp->e_event = E_INTERRUPT;
  73                 } else
  74                         evp->e_event = E_TIMEOUT;
  75                 return (0);
  76         }
  77         if (F_ISSET(clp, CL_SIGHUP | CL_SIGTERM | CL_SIGWINCH)) {
  78                 if (F_ISSET(clp, CL_SIGHUP)) {
  79                         evp->e_event = E_SIGHUP;
  80                         return (0);
  81                 }
  82                 if (F_ISSET(clp, CL_SIGTERM)) {
  83                         evp->e_event = E_SIGTERM;
  84                         return (0);
  85                 }
  86                 if (F_ISSET(clp, CL_SIGWINCH)) {
  87                         F_CLR(clp, CL_SIGWINCH);
  88                         if (cl_ssize(sp, 1, &lines, &columns, &changed))
  89                                 return (1);
  90                         if (changed) {
  91                                 (void)cl_resize(sp, lines, columns);
  92                                 evp->e_event = E_WRESIZE;
  93                                 return (0);
  94                         }
  95                         /* No real change, ignore the signal. */
  96                 }
  97         }
  98
  99         /* Set timer. */
 100         if (ms == 0)
 101                 tp = NULL;
 102         else {
 103                 t.tv_sec = ms / 1000;
 104                 t.tv_usec = (ms % 1000) * 1000;
 105                 tp = &t;
 106         }
 107
 108         /* Read input characters. */
 109 read:
 110         switch (cl_read(sp, LF_ISSET(EC_QUOTED | EC_RAW),
 111             clp->ibuf + clp->skip, SIZE(clp->ibuf) - clp->skip, &nr, tp)) {
 112         case INP_OK:
 113                 rc = INPUT2INT5(sp, clp->cw, clp->ibuf, nr + clp->skip,
 114                                 wp, wlen);
 115                 evp->e_csp = __UNCONST(wp);
 116                 evp->e_len = wlen;
 117                 evp->e_event = E_STRING;
 118                 if (rc < 0) {
 119                     int n = -rc;
 120                     memmove(clp->ibuf, clp->ibuf + nr + clp->skip - n, n);
 121                     clp->skip = n;
 122                     if (wlen == 0)
 123                         goto read;
 124                 } else if (rc == 0)
 125                     clp->skip = 0;
 126                 else
 127                     msgq(sp, M_ERR, "323|Invalid input. Truncated.");
 128                 break;
 129         case INP_ERR:
 130                 evp->e_event = E_ERR;
 131                 break;
 132         case INP_EOF:
 133                 evp->e_event = E_EOF;
 134                 break;
 135         case INP_INTR:
 136                 goto retest;
 137         case INP_TIMEOUT:
 138                 evp->e_event = E_TIMEOUT;
 139                 break;
 140         default:
 141                 abort();
 142         }
 143         return (0);
 144 }
 145
 146 /*
 147  * cl_read --
 148  *      Read characters from the input.
 149  */
 150 static input_t
 151 cl_read(SCR *sp, u_int32_t flags, char *bp, size_t blen, int *nrp, struct timeval *tp)
 152 {
 153         struct termios term1, term2;
 154         struct timeval poll;
 155         CL_PRIVATE *clp;
 156         GS *gp;
 157         fd_set rdfd;
 158         input_t rval;
 159         int maxfd, nr, term_reset;
 160
 161         gp = sp->gp;
 162         clp = CLP(sp);
 163         term_reset = 0;
 164
 165         /*
 166          * 1: A read from a file or a pipe.  In this case, the reads
 167          *    never timeout regardless.  This means that we can hang
 168          *    when trying to complete a map, but we're going to hang
 169          *    on the next read anyway.
 170          */
 171         if (!F_ISSET(clp, CL_STDIN_TTY)) {
 172                 switch (nr = read(STDIN_FILENO, bp, blen)) {
 173                 case 0:
 174                         return (INP_EOF);
 175                 case -1:
 176                         goto err;
 177                 default:
 178                         *nrp = nr;
 179                         return (INP_OK);
 180                 }
 181                 /* NOTREACHED */
 182         }
 183
 184         /*
 185          * 2: A read with an associated timeout, e.g., trying to complete
 186          *    a map sequence.  If input exists, we fall into #3.
 187          */
 188         FD_ZERO(&rdfd);
 189         poll.tv_sec = 0;
 190         poll.tv_usec = 0;
 191         if (tp != NULL) {
 192                 FD_SET(STDIN_FILENO, &rdfd);
 193                 switch (select(STDIN_FILENO + 1,
 194                     &rdfd, NULL, NULL, tp == NULL ? &poll : tp)) {
 195                 case 0:
 196                         return (INP_TIMEOUT);
 197                 case -1:
 198                         goto err;
 199                 default:
 200                         break;
 201                 }
 202         }
 203
 204         /*
 205          * The user can enter a key in the editor to quote a character.  If we
 206          * get here and the next key is supposed to be quoted, do what we can.
 207          * Reset the tty so that the user can enter a ^C, ^Q, ^S.  There's an
 208          * obvious race here, when the key has already been entered, but there's
 209          * nothing that we can do to fix that problem.
 210          *
 211          * The editor can ask for the next literal character even thought it's
 212          * generally running in line-at-a-time mode.  Do what we can.
 213          */
 214         if (LF_ISSET(EC_QUOTED | EC_RAW) && !tcgetattr(STDIN_FILENO, &term1)) {
 215                 term_reset = 1;
 216                 if (LF_ISSET(EC_QUOTED)) {
 217                         term2 = term1;
 218                         term2.c_lflag &= ~ISIG;
 219                         term2.c_iflag &= ~(IXON | IXOFF);
 220                         (void)tcsetattr(STDIN_FILENO,
 221                             TCSASOFT | TCSADRAIN, &term2);
 222                 } else
 223                         (void)tcsetattr(STDIN_FILENO,
 224                             TCSASOFT | TCSADRAIN, &clp->vi_enter);
 225         }
 226
 227         /*
 228          * 3: Wait for input.
 229          *
 230          * Select on the command input and scripting window file descriptors.
 231          * It's ugly that we wait on scripting file descriptors here, but it's
 232          * the only way to keep from locking out scripting windows.
 233          */
 234         if (F_ISSET(gp, G_SCRWIN)) {
 235                 FD_ZERO(&rdfd);
 236                 FD_SET(STDIN_FILENO, &rdfd);
 237                 maxfd = STDIN_FILENO;
 238                 if (sscr_check_input(sp, &rdfd, maxfd))
 239                         goto err;
 240         }
 241
 242         /*
 243          * 4: Read the input.
 244          *
 245          * !!!
 246          * What's going on here is some scary stuff.  Ex runs the terminal in
 247          * canonical mode.  So, the <newline> character terminating a line of
 248          * input is returned in the buffer, but a trailing <EOF> character is
 249          * not similarly included.  As ex uses 0<EOF> and ^<EOF> as autoindent
 250          * commands, it has to see the trailing <EOF> characters to determine
 251          * the difference between the user entering "0ab" and "0<EOF>ab".  We
 252          * leave an extra slot in the buffer, so that we can add a trailing
 253          * <EOF> character if the buffer isn't terminated by a <newline>.  We
 254          * lose if the buffer is too small for the line and exactly N characters
 255          * are entered followed by an <EOF> character.
 256          */
 257 #define ONE_FOR_EOF     1
 258         switch (nr = read(STDIN_FILENO, bp, blen - ONE_FOR_EOF)) {
 259         case  0:                                /* EOF. */
 260                 /*
 261                  * ^D in canonical mode returns a read of 0, i.e. EOF.  EOF is
 262                  * a valid command, but we don't want to loop forever because
 263                  * the terminal driver is returning EOF because the user has
 264                  * disconnected. The editor will almost certainly try to write
 265                  * something before this fires, which should kill us, but You
 266                  * Never Know.
 267                  */
 268                 if (++clp->eof_count < 50) {
 269                         bp[0] = clp->orig.c_cc[VEOF];
 270                         *nrp = 1;
 271                         rval = INP_OK;
 272
 273                 } else
 274                         rval = INP_EOF;
 275                 break;
 276         case -1:                                /* Error or interrupt. */
 277 err:            if (errno == EINTR)
 278                         rval = INP_INTR;
 279                 else {
 280                         rval = INP_ERR;
 281                         msgq(sp, M_SYSERR, "input");
 282                 }
 283                 break;
 284         default:                                /* Input characters. */
 285                 if (F_ISSET(sp, SC_EX) && bp[nr - 1] != '\n')
 286                         bp[nr++] = clp->orig.c_cc[VEOF];
 287                 *nrp = nr;
 288                 clp->eof_count = 0;
 289                 rval = INP_OK;
 290                 break;
 291         }
 292
 293         /* Restore the terminal state if it was modified. */
 294         if (term_reset)
 295                 (void)tcsetattr(STDIN_FILENO, TCSASOFT | TCSADRAIN, &term1);
 296         return (rval);
 297 }
 298
 299 /*
 300  * cl_resize --
 301  *      Reset the options for a resize event.
 302  */
 303 static int
 304 cl_resize(SCR *sp, size_t lines, size_t columns)
 305 {
 306         int rval;
 307
 308         rval = api_opts_set(sp, L("lines"), NULL, lines, 0);
 309         if (api_opts_set(sp, L("columns"), NULL, columns, 0))
 310                 rval = 1;
 311         return (rval);
 312 }