rote.c

   1 /*
   2 LICENSE INFORMATION:
   3 This program is free software; you can redistribute it and/or
   4 modify it under the terms of the GNU Lesser General Public
   5 License (LGPL) as published by the Free Software Foundation.
   6
   7 Please refer to the COPYING file for more information.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 General Public License for more details.
  13
  14 You should have received a copy of the GNU Lesser General Public
  15 License along with this program; if not, write to the Free Software
  16 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  17
  18 Copyright (c) 2004 Bruno T. C. de Oliveira
  19 */
  20
  21
  22 #include "rote.h"
  23 #include "roteprivate.h"
  24 #include <stdlib.h>
  25 #include <pty.h>
  26 #include <stdio.h>
  27 #include <string.h>
  28
  29 #define ROTE_VT_UPDATE_ITERATIONS 5
  30
  31 RoteTerm *rote_vt_create(int rows, int cols) {
  32    RoteTerm *rt;
  33    int i, j;
  34
  35    if (rows <= 0 || cols <= 0) return NULL;
  36
  37    if (! (rt = (RoteTerm*) malloc(sizeof(RoteTerm))) ) return NULL;
  38    memset(rt, 0, sizeof(RoteTerm));
  39
  40    /* record dimensions */
  41    rt->rows = rows;
  42    rt->cols = cols;
  43
  44    /* create the cell matrix */
  45    rt->cells = (RoteCell**) malloc(sizeof(RoteCell*) * rt->rows);
  46    for (i = 0; i < rt->rows; i++) {
  47       /* create row */
  48       rt->cells[i] = (RoteCell*) malloc(sizeof(RoteCell) * rt->cols);
  49
  50       /* fill row with spaces */
  51       for (j = 0; j < rt->cols; j++) {
  52          rt->cells[i][j].ch = 0x20;    /* a space */
  53          rt->cells[i][j].attr = 0x70;  /* white text, black background */
  54       }
  55    }
  56
  57    /* allocate dirtiness array */
  58    rt->line_dirty = (bool*) malloc(sizeof(bool) * rt->rows);
  59
  60    /* initialization of other public fields */
  61    rt->crow = rt->ccol = 0;
  62    rt->curattr = 0x70;  /* white text over black background */
  63
  64    /* allocate private data */
  65    rt->pd = (RoteTermPrivate*) malloc(sizeof(RoteTermPrivate));
  66    memset(rt->pd, 0, sizeof(RoteTermPrivate));
  67
  68    rt->pd->pty = -1;  /* no pty for now */
  69
  70    /* initial scrolling area is the whole window */
  71    rt->pd->scrolltop = 0;
  72    rt->pd->scrollbottom = rt->rows - 1;
  73
  74    #ifdef DEBUG
  75    fprintf(stderr, "Created a %d x %d terminal.\n", rt->rows, rt->cols);
  76    #endif
  77
  78    return rt;
  79 }
  80
  81 void rote_vt_destroy(RoteTerm *rt) {
  82    int i;
  83    if (!rt) return;
  84
  85    free(rt->pd);
  86    free(rt->line_dirty);
  87    for (i = 0; i < rt->rows; i++) free(rt->cells[i]);
  88    free(rt->cells);
  89    free(rt);
  90 }
  91
  92 static void default_cur_set_attr(WINDOW *win, unsigned char attr) {
  93    int cp = ROTE_ATTR_BG(attr) * 8 + 7 - ROTE_ATTR_FG(attr);
  94    if (!cp) wattrset(win, A_NORMAL);
  95    else     wattrset(win, COLOR_PAIR(cp));
  96
  97    if (ROTE_ATTR_BOLD(attr))     wattron(win, A_BOLD);
  98    if (ROTE_ATTR_BLINK(attr))    wattron(win, A_BLINK);
  99 }
 100
 101 static inline unsigned char ensure_printable(unsigned char ch)
 102                                         { return ch >= 32 ? ch : 32; }
 103
 104 void rote_vt_draw(RoteTerm *rt, WINDOW *win, int srow, int scol,
 105                                 void (*cur_set_attr)(WINDOW*,unsigned char)) {
 106
 107    int i, j;
 108    rote_vt_update(rt);
 109
 110    if (!cur_set_attr) cur_set_attr = default_cur_set_attr;
 111    for (i = 0; i < rt->rows; i++) {
 112       wmove(win, srow + i, scol);
 113       for (j = 0; j < rt->cols; j++) {
 114          (*cur_set_attr)(win, rt->cells[i][j].attr);
 115          waddch(win, ensure_printable(rt->cells[i][j].ch));
 116       }
 117    }
 118
 119    wmove(win, srow + rt->crow, scol + rt->ccol);
 120 }
 121
 122 pid_t rote_vt_forkpty(RoteTerm *rt, const char *command) {
 123    struct winsize ws;
 124    pid_t childpid;
 125
 126    ws.ws_row = rt->rows;
 127    ws.ws_col = rt->cols;
 128    ws.ws_xpixel = ws.ws_ypixel = 0;
 129
 130    childpid = forkpty(&rt->pd->pty, NULL, NULL, &ws);
 131    if (childpid < 0) return -1;
 132
 133    if (childpid == 0) {
 134       /* we are the child, running under the slave side of the pty. */
 135
 136       /* Cajole application into using linux-console-compatible escape
 137        * sequences (which is what we are prepared to interpret) */
 138       setenv("TERM", "linux", 1);
 139
 140       /* Now we will exec /bin/sh -c command. */
 141       execl("/bin/sh", "/bin/sh", "-c", command, NULL);
 142
 143       fprintf(stderr, "\nexecl() failed.\nCommand: '%s'\n", command);
 144       exit(127);  /* error exec'ing */
 145    }
 146
 147    /* if we got here we are the parent process */
 148    rt->childpid = childpid;
 149    return childpid;
 150 }
 151
 152 void rote_vt_forsake_child(RoteTerm *rt) {
 153    if (rt->pd->pty >= 0) close(rt->pd->pty);
 154    rt->pd->pty = -1;
 155    rt->childpid = 0;
 156 }
 157
 158 void rote_vt_update(RoteTerm *rt) {
 159    fd_set ifs;
 160    struct timeval tvzero;
 161    char buf[512];
 162    int bytesread;
 163    int n = ROTE_VT_UPDATE_ITERATIONS;
 164    if (rt->pd->pty < 0) return;  /* nothing to pump */
 165
 166    while (n--) { /* iterate at most ROVE_VT_UPDATE_ITERATIONS times.
 167                   * As Phil Endecott pointed out, if we don't restrict this,
 168                   * a program that floods the terminal with output
 169                   * could cause this loop to iterate forever, never
 170                   * being able to catch up. So we'll rely on the client
 171                   * calling rote_vt_update often, as the documentation
 172                   * recommends :-) */
 173
 174       /* check if pty has something to say */
 175       FD_ZERO(&ifs); FD_SET(rt->pd->pty, &ifs);
 176       tvzero.tv_sec = 0; tvzero.tv_usec = 0;
 177
 178       if (select(rt->pd->pty + 1, &ifs, NULL, NULL, &tvzero) <= 0)
 179          return; /* nothing to read, or select() failed */
 180
 181       /* read what we can. This is guaranteed not to block, since
 182        * select() told us there was something to read. */
 183       bytesread = read(rt->pd->pty, buf, 512);
 184       if (bytesread <= 0) return;
 185
 186       /* inject the data into the terminal */
 187       rote_vt_inject(rt, buf, bytesread);
 188    }
 189 }
 190
 191 void rote_vt_write(RoteTerm *rt, const char *data, int len) {
 192    if (rt->pd->pty < 0) {
 193       /* no pty, so just inject the data plain and simple */
 194       rote_vt_inject(rt, data, len);
 195       return;
 196    }
 197
 198    /* write data to pty. Keep calling write() until we have written
 199     * everything. */
 200    while (len > 0) {
 201       int byteswritten = write(rt->pd->pty, data, len);
 202       if (byteswritten < 0) {
 203          /* very ugly way to inform the error. Improvements welcome! */
 204          static char errormsg[] = "\n(ROTE: pty write() error)\n";
 205          rote_vt_inject(rt, errormsg, strlen(errormsg));
 206          return;
 207       }
 208
 209       data += byteswritten;
 210       len  -= byteswritten;
 211    }
 212 }
 213
 214 void rote_vt_install_handler(RoteTerm *rt, rote_es_handler_t handler) {
 215    rt->pd->handler = handler;
 216 }
 217
 218 void *rote_vt_take_snapshot(RoteTerm *rt) {
 219    int i;
 220    int bytes_per_row = sizeof(RoteCell) * rt->cols;
 221    void *buf = malloc(bytes_per_row * rt->rows);
 222    void *ptr = buf;
 223
 224    for (i = 0; i < rt->rows; i++, ptr += bytes_per_row)
 225       memcpy(ptr, rt->cells[i], bytes_per_row);
 226
 227    return buf;
 228 }
 229
 230 void rote_vt_restore_snapshot(RoteTerm *rt, void *snapbuf) {
 231    int i;
 232    int bytes_per_row = sizeof(RoteCell) * rt->cols;
 233
 234    for (i = 0; i < rt->rows; i++, snapbuf += bytes_per_row) {
 235       rt->line_dirty[i] = true;
 236       memcpy(rt->cells[i], snapbuf, bytes_per_row);
 237    }
 238 }
 239
 240 int rote_vt_get_pty_fd(RoteTerm *rt) {
 241    return rt->pd->pty;
 242 }
 243