readline/examples/rlptytest.c

   1 /*
   2  *
   3  * Another test harness for the readline callback interface.
   4  *
   5  * Author: Bob Rossi <bob@brasko.net>
   6  */
   7
   8 #if defined (HAVE_CONFIG_H)
   9 #include <config.h>
  10 #endif
  11
  12 #include <stdio.h>
  13 #include <sys/types.h>
  14 #include <errno.h>
  15 #include <curses.h>
  16
  17 #include <stdlib.h>
  18 #include <unistd.h>
  19
  20 #include <signal.h>
  21
  22 #if 1   /* LINUX */
  23 #include <pty.h>
  24 #else
  25 #include <util.h>
  26 #endif
  27
  28 #ifdef READLINE_LIBRARY
  29 #  include "readline.h"
  30 #else
  31 #  include <readline/readline.h>
  32 #endif
  33
  34 /**
  35  * Master/Slave PTY used to keep readline off of stdin/stdout.
  36  */
  37 static int masterfd = -1;
  38 static int slavefd;
  39
  40 void
  41 sigint (s)
  42      int s;
  43 {
  44   tty_reset (STDIN_FILENO);
  45   close (masterfd);
  46   close (slavefd);
  47   printf ("\n");
  48   exit (0);
  49 }
  50
  51 void
  52 sigwinch (s)
  53      int s;
  54 {
  55   rl_resize_terminal ();
  56 }
  57
  58 static int
  59 user_input()
  60 {
  61   int size;
  62   const int MAX = 1024;
  63   char *buf = (char *)malloc(MAX+1);
  64
  65   size = read (STDIN_FILENO, buf, MAX);
  66   if (size == -1)
  67     return -1;
  68
  69   size = write (masterfd, buf, size);
  70   if (size == -1)
  71     return -1;
  72
  73   return 0;
  74 }
  75
  76 static int
  77 readline_input()
  78 {
  79   const int MAX = 1024;
  80   char *buf = (char *)malloc(MAX+1);
  81   int size;
  82
  83   size = read (masterfd, buf, MAX);
  84   if (size == -1)
  85     {
  86       free( buf );
  87       buf = NULL;
  88       return -1;
  89     }
  90
  91   buf[size] = 0;
  92
  93   /* Display output from readline */
  94   if ( size > 0 )
  95     fprintf(stderr, "%s", buf);
  96
  97   free( buf );
  98   buf = NULL;
  99   return 0;
 100 }
 101
 102 static void
 103 rlctx_send_user_command(char *line)
 104 {
 105   /* This happens when rl_callback_read_char gets EOF */
 106   if ( line == NULL )
 107     return;
 108
 109   if (strcmp (line, "exit") == 0) {
 110         tty_reset (STDIN_FILENO);
 111         close (masterfd);
 112         close (slavefd);
 113         printf ("\n");
 114         exit (0);
 115   }
 116
 117   /* Don't add the enter command */
 118   if ( line && *line != '\0' )
 119     add_history(line);
 120 }
 121
 122 static void
 123 custom_deprep_term_function ()
 124 {
 125 }
 126
 127 static int
 128 init_readline (int inputfd, int outputfd)
 129 {
 130   FILE *inputFILE, *outputFILE;
 131
 132   inputFILE = fdopen (inputfd, "r");
 133   if (!inputFILE)
 134     return -1;
 135
 136   outputFILE = fdopen (outputfd, "w");
 137   if (!outputFILE)
 138     return -1;
 139
 140   rl_instream = inputFILE;
 141   rl_outstream = outputFILE;
 142
 143   /* Tell readline what the prompt is if it needs to put it back */
 144   rl_callback_handler_install("(rltest):  ", rlctx_send_user_command);
 145
 146   /* Set the terminal type to dumb so the output of readline can be
 147    * understood by tgdb */
 148   if ( rl_reset_terminal("dumb") == -1 )
 149     return -1;
 150
 151   /* For some reason, readline can not deprep the terminal.
 152    * However, it doesn't matter because no other application is working on
 153    * the terminal besides readline */
 154   rl_deprep_term_function = custom_deprep_term_function;
 155
 156   using_history();
 157   read_history(".history");
 158
 159   return 0;
 160 }
 161
 162 static int
 163 main_loop(void)
 164 {
 165   fd_set rset;
 166   int max;
 167
 168   max = (masterfd > STDIN_FILENO) ? masterfd : STDIN_FILENO;
 169   max = (max > slavefd) ? max : slavefd;
 170
 171   for (;;)
 172     {
 173       /* Reset the fd_set, and watch for input from GDB or stdin */
 174       FD_ZERO(&rset);
 175
 176       FD_SET(STDIN_FILENO, &rset);
 177       FD_SET(slavefd, &rset);
 178       FD_SET(masterfd, &rset);
 179
 180       /* Wait for input */
 181       if (select(max + 1, &rset, NULL, NULL, NULL) == -1)
 182         {
 183           if (errno == EINTR)
 184              continue;
 185           else
 186             return -1;
 187         }
 188
 189       /* Input received through the pty:  Handle it
 190        * Wrote to masterfd, slave fd has that input, alert readline to read it.
 191        */
 192       if (FD_ISSET(slavefd, &rset))
 193         rl_callback_read_char();
 194
 195       /* Input received through the pty.
 196        * Readline read from slavefd, and it wrote to the masterfd.
 197        */
 198       if (FD_ISSET(masterfd, &rset))
 199         if ( readline_input() == -1 )
 200           return -1;
 201
 202       /* Input received:  Handle it, write to masterfd (input to readline) */
 203       if (FD_ISSET(STDIN_FILENO, &rset))
 204         if ( user_input() == -1 )
 205           return -1;
 206   }
 207
 208   return 0;
 209 }
 210
 211 /* The terminal attributes before calling tty_cbreak */
 212 static struct termios save_termios;
 213 static struct winsize size;
 214 static enum { RESET, TCBREAK } ttystate = RESET;
 215
 216 /* tty_cbreak: Sets terminal to cbreak mode. Also known as noncanonical mode.
 217  *    1. Signal handling is still turned on, so the user can still type those.
 218  *    2. echo is off
 219  *    3. Read in one char at a time.
 220  *
 221  * fd    - The file descriptor of the terminal
 222  *
 223  * Returns: 0 on sucess, -1 on error
 224  */
 225 int tty_cbreak(int fd){
 226    struct termios buf;
 227     int ttysavefd = -1;
 228
 229    if(tcgetattr(fd, &save_termios) < 0)
 230       return -1;
 231
 232    buf = save_termios;
 233    buf.c_lflag &= ~(ECHO | ICANON);
 234    buf.c_iflag &= ~(ICRNL | INLCR);
 235    buf.c_cc[VMIN] = 1;
 236    buf.c_cc[VTIME] = 0;
 237
 238 #if defined (VLNEXT) && defined (_POSIX_VDISABLE)
 239    buf.c_cc[VLNEXT] = _POSIX_VDISABLE;
 240 #endif
 241
 242 #if defined (VDSUSP) && defined (_POSIX_VDISABLE)
 243    buf.c_cc[VDSUSP] = _POSIX_VDISABLE;
 244 #endif
 245
 246   /* enable flow control; only stty start char can restart output */
 247 #if 0
 248   buf.c_iflag |= (IXON|IXOFF);
 249 #ifdef IXANY
 250   buf.c_iflag &= ~IXANY;
 251 #endif
 252 #endif
 253
 254   /* disable flow control; let ^S and ^Q through to pty */
 255   buf.c_iflag &= ~(IXON|IXOFF);
 256 #ifdef IXANY
 257   buf.c_iflag &= ~IXANY;
 258 #endif
 259
 260   if(tcsetattr(fd, TCSAFLUSH, &buf) < 0)
 261       return -1;
 262
 263    ttystate = TCBREAK;
 264    ttysavefd = fd;
 265
 266    /* set size */
 267    if(ioctl(fd, TIOCGWINSZ, (char *)&size) < 0)
 268       return -1;
 269
 270 #ifdef DEBUG
 271    err_msg("%d rows and %d cols\n", size.ws_row, size.ws_col);
 272 #endif
 273
 274    return (0);
 275 }
 276
 277 int
 278 tty_off_xon_xoff (int fd)
 279 {
 280   struct termios buf;
 281   int ttysavefd = -1;
 282
 283   if(tcgetattr(fd, &buf) < 0)
 284     return -1;
 285
 286   buf.c_iflag &= ~(IXON|IXOFF);
 287
 288   if(tcsetattr(fd, TCSAFLUSH, &buf) < 0)
 289     return -1;
 290
 291   return 0;
 292 }
 293
 294 /* tty_reset: Sets the terminal attributes back to their previous state.
 295  * PRE: tty_cbreak must have already been called.
 296  *
 297  * fd    - The file descrioptor of the terminal to reset.
 298  *
 299  * Returns: 0 on success, -1 on error
 300  */
 301 int tty_reset(int fd)
 302 {
 303    if(ttystate != TCBREAK)
 304       return (0);
 305
 306    if(tcsetattr(fd, TCSAFLUSH, &save_termios) < 0)
 307       return (-1);
 308
 309    ttystate = RESET;
 310
 311    return 0;
 312 }
 313
 314 int
 315 main()
 316 {
 317   int val;
 318   val = openpty (&masterfd, &slavefd, NULL, NULL, NULL);
 319   if (val == -1)
 320     return -1;
 321
 322   val = tty_off_xon_xoff (masterfd);
 323   if (val == -1)
 324     return -1;
 325
 326   signal (SIGWINCH, sigwinch);
 327   signal (SIGINT, sigint);
 328
 329   val = init_readline (slavefd, slavefd);
 330   if (val == -1)
 331     return -1;
 332
 333   val = tty_cbreak (STDIN_FILENO);
 334   if (val == -1)
 335     return -1;
 336
 337   val = main_loop ();
 338
 339   tty_reset (STDIN_FILENO);
 340
 341   if (val == -1)
 342     return -1;
 343
 344   return 0;
 345 }