libguile/ioext.c

   1 /*      Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
   2  *
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2, or (at your option)
   6  * any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this software; see the file COPYING.  If not, write to
  15  * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  16  * Boston, MA 02111-1307 USA
  17  *
  18  * As a special exception, the Free Software Foundation gives permission
  19  * for additional uses of the text contained in its release of GUILE.
  20  *
  21  * The exception is that, if you link the GUILE library with other files
  22  * to produce an executable, this does not by itself cause the
  23  * resulting executable to be covered by the GNU General Public License.
  24  * Your use of that executable is in no way restricted on account of
  25  * linking the GUILE library code into it.
  26  *
  27  * This exception does not however invalidate any other reasons why
  28  * the executable file might be covered by the GNU General Public License.
  29  *
  30  * This exception applies only to the code released by the
  31  * Free Software Foundation under the name GUILE.  If you copy
  32  * code from other Free Software Foundation releases into a copy of
  33  * GUILE, as the General Public License permits, the exception does
  34  * not apply to the code that you add in this way.  To avoid misleading
  35  * anyone as to the status of such modified files, you must delete
  36  * this exception notice from them.
  37  *
  38  * If you write modifications of your own for GUILE, it is your choice
  39  * whether to permit this exception to apply to your modifications.
  40  * If you do not wish that, delete this exception notice.  */
  41
  42 /* Software engineering face-lift by Greg J. Badros, 11-Dec-1999,
  43    gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */
  44
  45 \f
  46
  47
  48 #include <stdio.h>
  49 #include "libguile/_scm.h"
  50 #include "libguile/ports.h"
  51 #include "libguile/read.h"
  52 #include "libguile/fports.h"
  53 #include "libguile/unif.h"
  54 #include "libguile/chars.h"
  55 #include "libguile/feature.h"
  56 #include "libguile/root.h"
  57 #include "libguile/strings.h"
  58
  59 #include "libguile/validate.h"
  60 #include "libguile/ioext.h"
  61
  62 #include <fcntl.h>
  63
  64 #ifdef HAVE_STRING_H
  65 #include <string.h>
  66 #endif
  67 #ifdef HAVE_UNISTD_H
  68 #include <unistd.h>
  69 #endif
  70 \f
  71
  72 SCM_DEFINE (scm_read_string_x_partial, "read-string!/partial", 1, 3, 0,
  73             (SCM str, SCM port_or_fdes, SCM start, SCM end),
  74             "Read characters from an fport or file descriptor into a\n"
  75             "string @var{str}.  This procedure is scsh-compatible\n"
  76             "and can efficiently read large strings.  It will:\n\n"
  77             "@itemize\n"
  78             "@item\n"
  79             "attempt to fill the entire string, unless the @var{start}\n"
  80             "and/or @var{end} arguments are supplied.  i.e., @var{start}\n"
  81             "defaults to 0 and @var{end} defaults to\n"
  82             "@code{(string-length str)}\n"
  83             "@item\n"
  84             "use the current input port if @var{port_or_fdes} is not\n"
  85             "supplied.\n"
  86             "@item\n"
  87             "read any characters that are currently available,\n"
  88             "without waiting for the rest (short reads are possible).\n\n"
  89             "@item\n"
  90             "wait for as long as it needs to for the first character to\n"
  91             "become available, unless the port is in non-blocking mode\n"
  92             "@item\n"
  93             "return @code{#f} if end-of-file is encountered before reading\n"
  94             "any characters, otherwise return the number of characters\n"
  95             "read.\n"
  96             "@item\n"
  97             "return 0 if the port is in non-blocking mode and no characters\n"
  98             "are immediately available.\n"
  99             "@item\n"
 100             "return 0 if the request is for 0 bytes, with no\n"
 101             "end-of-file check\n"
 102             "@end itemize")
 103 #define FUNC_NAME s_scm_read_string_x_partial
 104 {
 105   char *dest;
 106   long read_len;
 107   long chars_read = 0;
 108   int fdes;
 109
 110   {
 111     long offset;
 112     long last;
 113
 114     SCM_VALIDATE_SUBSTRING_SPEC_COPY (1, str, dest, 3, start, offset,
 115                                       4, end, last);
 116     dest += offset;
 117     read_len = last - offset;
 118   }
 119
 120   if (SCM_INUMP (port_or_fdes))
 121     fdes = SCM_INUM (port_or_fdes);
 122   else
 123     {
 124       SCM port = SCM_UNBNDP (port_or_fdes) ? scm_cur_inp : port_or_fdes;
 125
 126       SCM_VALIDATE_OPFPORT (2, port);
 127       SCM_VALIDATE_INPUT_PORT (2, port);
 128
 129       /* if there's anything in the port buffers, use it, but then
 130          don't touch the file descriptor.  otherwise the
 131          "return immediately if something is available" rule may
 132          be violated.  */
 133       chars_read = scm_take_from_input_buffers (port, dest, read_len);
 134       fdes = SCM_FPORT_FDES (port);
 135     }
 136
 137   if (chars_read == 0 && read_len > 0) /* don't confuse read_len == 0 with
 138                                           EOF.  */
 139     {
 140       SCM_SYSCALL (chars_read = read (fdes, dest, read_len));
 141       if (chars_read == -1)
 142         {
 143 #if defined (EWOULDBLOCK) || defined (EAGAIN)
 144           if (
 145 #if defined (EWOULDBLOCK)
 146               errno == EWOULDBLOCK
 147 #else
 148               errno == EAGAIN
 149 #endif
 150               )
 151             chars_read = 0;
 152           else
 153 #endif
 154             SCM_SYSERROR;
 155         }
 156       else if (chars_read == 0)
 157         return SCM_BOOL_F;
 158     }
 159   return scm_long2num (chars_read);
 160 }
 161 #undef FUNC_NAME
 162
 163 SCM_DEFINE (scm_read_delimited_x, "%read-delimited!", 3, 3, 0,
 164             (SCM delims, SCM str, SCM gobble, SCM port, SCM start, SCM end),
 165             "Read characters from @var{port} into @var{str} until one of the\n"
 166             "characters in the @var{delims} string is encountered.  If @var{gobble}\n"
 167             "is true, discard the delimiter character; otherwise, leave it\n"
 168             "in the input stream for the next read.\n"
 169             "If @var{port} is not specified, use the value of\n"
 170             "@code{(current-input-port)}.  If @var{start} or @var{end} are specified,\n"
 171             "store data only into the substring of @var{str} bounded by @var{start}\n"
 172             "and @var{end} (which default to the beginning and end of the string,\n"
 173             "respectively).\n\n"
 174             "Return a pair consisting of the delimiter that terminated the string and\n"
 175             "the number of characters read.  If reading stopped at the end of file,\n"
 176             "the delimiter returned is the @var{eof-object}; if the string was filled\n"
 177             "without encountering a delimiter, this value is @var{#f}.")
 178 #define FUNC_NAME s_scm_read_delimited_x
 179 {
 180   long j;
 181   char *buf;
 182   long cstart;
 183   long cend;
 184   int c;
 185   char *cdelims;
 186   int num_delims;
 187
 188   SCM_VALIDATE_STRING_COPY (1, delims, cdelims);
 189   num_delims = SCM_STRING_LENGTH (delims);
 190   SCM_VALIDATE_SUBSTRING_SPEC_COPY (2, str, buf, 5, start, cstart,
 191                                     6, end, cend);
 192   if (SCM_UNBNDP (port))
 193     port = scm_cur_inp;
 194   else
 195     SCM_VALIDATE_OPINPORT (4,port);
 196
 197   for (j = cstart; j < cend; j++)
 198     {
 199       int k;
 200
 201       c = scm_getc (port);
 202       for (k = 0; k < num_delims; k++)
 203         {
 204           if (cdelims[k] == c)
 205             {
 206               if (SCM_FALSEP (gobble))
 207                 scm_ungetc (c, port);
 208
 209               return scm_cons (SCM_MAKE_CHAR (c),
 210                                scm_long2num (j - cstart));
 211             }
 212         }
 213       if (c == EOF)
 214         return scm_cons (SCM_EOF_VAL,
 215                          scm_long2num (j - cstart));
 216
 217       buf[j] = c;
 218     }
 219   return scm_cons (SCM_BOOL_F, scm_long2num (j - cstart));
 220 }
 221 #undef FUNC_NAME
 222
 223 static unsigned char *
 224 scm_do_read_line (SCM port, int *len_p)
 225 {
 226   scm_port *pt = SCM_PTAB_ENTRY (port);
 227   unsigned char *end;
 228
 229   /* I thought reading lines was simple.  Mercy me.  */
 230
 231   /* The common case: the buffer contains a complete line.
 232      This needs to be fast.  */
 233   if ((end = memchr (pt->read_pos, '\n', (pt->read_end - pt->read_pos)))
 234            != 0)
 235     {
 236       int buf_len = (end + 1) - pt->read_pos;
 237       /* Allocate a buffer of the perfect size.  */
 238       unsigned char *buf = scm_must_malloc (buf_len + 1, "%read-line");
 239
 240       memcpy (buf, pt->read_pos, buf_len);
 241       pt->read_pos += buf_len;
 242
 243       buf[buf_len] = '\0';
 244
 245       *len_p = buf_len;
 246       return buf;
 247     }
 248
 249   /* The buffer contains no newlines.  */
 250   {
 251     /* When live, len is always the number of characters in the
 252        current buffer that are part of the current line.  */
 253     int len = (pt->read_end - pt->read_pos);
 254     int buf_size = (len < 50) ? 60 : len * 2;
 255     /* Invariant: buf always has buf_size + 1 characters allocated;
 256        the `+ 1' is for the final '\0'.  */
 257     unsigned char *buf = scm_must_malloc (buf_size + 1, "%read-line");
 258     int buf_len = 0;
 259
 260     for (;;)
 261       {
 262         if (buf_len + len > buf_size)
 263           {
 264             int new_size = (buf_len + len) * 2;
 265             buf = scm_must_realloc (buf, buf_size + 1, new_size + 1,
 266                                     "%read-line");
 267             buf_size = new_size;
 268           }
 269
 270         /* Copy what we've got out of the port, into our buffer.  */
 271         memcpy (buf + buf_len, pt->read_pos, len);
 272         buf_len += len;
 273         pt->read_pos += len;
 274
 275         /* If we had seen a newline, we're done now.  */
 276         if (end)
 277           break;
 278
 279         /* Get more characters.  */
 280         if (scm_fill_input (port) == EOF)
 281           {
 282             /* If we're missing a final newline in the file, return
 283                what we did get, sans newline.  */
 284             if (buf_len > 0)
 285               break;
 286
 287             free (buf);
 288             return 0;
 289           }
 290
 291         /* Search the buffer for newlines.  */
 292         if ((end = memchr (pt->read_pos, '\n',
 293                            (len = (pt->read_end - pt->read_pos))))
 294             != 0)
 295           len = (end - pt->read_pos) + 1;
 296       }
 297
 298     /* I wonder how expensive this realloc is.  */
 299     buf = scm_must_realloc (buf, buf_size + 1, buf_len + 1, "%read-line");
 300     buf[buf_len] = '\0';
 301     *len_p = buf_len;
 302     return buf;
 303   }
 304 }
 305
 306
 307 /*
 308  * %read-line
 309  * truncates any terminating newline from its input, and returns
 310  * a cons of the string read and its terminating character.  Doing
 311  * so makes it easy to implement the hairy `read-line' options
 312  * efficiently in Scheme.
 313  */
 314
 315 SCM_DEFINE (scm_read_line, "%read-line", 0, 1, 0,
 316             (SCM port),
 317             "Read a newline-terminated line from @var{port}, allocating storage as\n"
 318             "necessary.  The newline terminator (if any) is removed from the string,\n"
 319             "and a pair consisting of the line and its delimiter is returned.  The\n"
 320             "delimiter may be either a newline or the @var{eof-object}; if\n"
 321             "@code{%read-line} is called at the end of file, it returns the pair\n"
 322             "@code{(#<eof> . #<eof>)}.")
 323 #define FUNC_NAME s_scm_read_line
 324 {
 325   scm_port *pt;
 326   char *s;
 327   int slen;
 328   SCM line, term;
 329
 330   if (SCM_UNBNDP (port))
 331     port = scm_cur_inp;
 332   SCM_VALIDATE_OPINPORT (1,port);
 333
 334   pt = SCM_PTAB_ENTRY (port);
 335   if (pt->rw_active == SCM_PORT_WRITE)
 336     scm_ptobs[SCM_PTOBNUM (port)].flush (port);
 337
 338   s = (char *) scm_do_read_line (port, &slen);
 339
 340   if (s == NULL)
 341     term = line = SCM_EOF_VAL;
 342   else
 343     {
 344       if (s[slen-1] == '\n')
 345         {
 346           term = SCM_MAKE_CHAR ('\n');
 347           s[slen-1] = '\0';
 348           line = scm_take_str (s, slen-1);
 349           scm_done_malloc (-1);
 350           SCM_INCLINE (port);
 351         }
 352       else
 353         {
 354           /* Fix: we should check for eof on the port before assuming this. */
 355           term = SCM_EOF_VAL;
 356           line = scm_take_str (s, slen);
 357           SCM_COL (port) += slen;
 358         }
 359     }
 360
 361   if (pt->rw_random)
 362     pt->rw_active = SCM_PORT_READ;
 363
 364   return scm_cons (line, term);
 365 }
 366 #undef FUNC_NAME
 367
 368 SCM_DEFINE (scm_write_line, "write-line", 1, 1, 0,
 369             (SCM obj, SCM port),
 370             "Display @var{obj} and a newline character to @var{port}.  If @var{port}\n"
 371             "is not specified, @code{(current-output-port)} is used.  This function\n"
 372             "is equivalent to:\n\n"
 373             "@smalllisp\n"
 374             "(display obj [port])\n"
 375             "(newline [port])\n"
 376             "@end smalllisp")
 377 #define FUNC_NAME s_scm_write_line
 378 {
 379   scm_display (obj, port);
 380   return scm_newline (port);
 381 }
 382 #undef FUNC_NAME
 383
 384 SCM_DEFINE (scm_ftell, "ftell", 1, 0, 0,
 385             (SCM object),
 386             "Returns an integer representing the current position of @var{fd/port},\n"
 387             "measured from the beginning.  Equivalent to:\n"
 388             "@smalllisp\n"
 389             "(seek port 0 SEEK_CUR)\n"
 390             "@end smalllisp")
 391 #define FUNC_NAME s_scm_ftell
 392 {
 393   return scm_seek (object, SCM_INUM0, SCM_MAKINUM (SEEK_CUR));
 394 }
 395 #undef FUNC_NAME
 396
 397
 398 #if (SCM_DEBUG_DEPRECATED == 0)
 399
 400 SCM_DEFINE (scm_fseek, "fseek", 3, 0, 0,
 401             (SCM object, SCM offset, SCM whence),
 402             "Obsolete.  Almost the same as seek, above, but the return value is\n"
 403             "unspecified.")
 404 #define FUNC_NAME s_scm_fseek
 405 {
 406   scm_seek (object, offset, whence);
 407   return SCM_UNSPECIFIED;
 408 }
 409 #undef FUNC_NAME
 410
 411 #endif  /* SCM_DEBUG_DEPRECATED == 0 */
 412
 413
 414 SCM_DEFINE (scm_redirect_port, "redirect-port", 2, 0, 0,
 415             (SCM old, SCM new),
 416             "This procedure takes two ports and duplicates the underlying file\n"
 417             "descriptor from @var{old-port} into @var{new-port}.  The\n"
 418             "current file descriptor in @var{new-port} will be closed.\n"
 419             "After the redirection the two ports will share a file position\n"
 420             "and file status flags.\n\n"
 421             "The return value is unspecified.\n\n"
 422             "Unexpected behaviour can result if both ports are subsequently used\n"
 423             "and the original and/or duplicate ports are buffered.\n\n"
 424             "This procedure does not have any side effects on other ports or\n"
 425             "revealed counts.")
 426 #define FUNC_NAME s_scm_redirect_port
 427 {
 428   int ans, oldfd, newfd;
 429   struct scm_fport *fp;
 430
 431   old = SCM_COERCE_OUTPORT (old);
 432   new = SCM_COERCE_OUTPORT (new);
 433
 434   SCM_VALIDATE_OPFPORT (1,old);
 435   SCM_VALIDATE_OPFPORT (2,new);
 436   oldfd = SCM_FPORT_FDES (old);
 437   fp = SCM_FSTREAM (new);
 438   newfd = fp->fdes;
 439   if (oldfd != newfd)
 440     {
 441       scm_port *pt = SCM_PTAB_ENTRY (new);
 442       scm_port *old_pt = SCM_PTAB_ENTRY (old);
 443       scm_ptob_descriptor *ptob = &scm_ptobs[SCM_PTOBNUM (new)];
 444
 445       /* must flush to old fdes.  */
 446       if (pt->rw_active == SCM_PORT_WRITE)
 447         ptob->flush (new);
 448       else if (pt->rw_active == SCM_PORT_READ)
 449         scm_end_input (new);
 450       ans = dup2 (oldfd, newfd);
 451       if (ans == -1)
 452         SCM_SYSERROR;
 453       pt->rw_random = old_pt->rw_random;
 454       /* continue using existing buffers, even if inappropriate.  */
 455     }
 456   return SCM_UNSPECIFIED;
 457 }
 458 #undef FUNC_NAME
 459
 460 SCM_DEFINE (scm_dup_to_fdes, "dup->fdes", 1, 1, 0,
 461             (SCM fd_or_port, SCM fd),
 462             "Returns an integer file descriptor.")
 463 #define FUNC_NAME s_scm_dup_to_fdes
 464 {
 465   int oldfd, newfd, rv;
 466
 467   fd_or_port = SCM_COERCE_OUTPORT (fd_or_port);
 468
 469   if (SCM_INUMP (fd_or_port))
 470     oldfd = SCM_INUM (fd_or_port);
 471   else
 472     {
 473       SCM_VALIDATE_OPFPORT (1,fd_or_port);
 474       oldfd = SCM_FPORT_FDES (fd_or_port);
 475     }
 476
 477   if (SCM_UNBNDP (fd))
 478     {
 479       newfd = dup (oldfd);
 480       if (newfd == -1)
 481         SCM_SYSERROR;
 482       fd = SCM_MAKINUM (newfd);
 483     }
 484   else
 485     {
 486       SCM_VALIDATE_INUM_COPY (2, fd, newfd);
 487       if (oldfd != newfd)
 488         {
 489           scm_evict_ports (newfd);      /* see scsh manual.  */
 490           rv = dup2 (oldfd, newfd);
 491           if (rv == -1)
 492             SCM_SYSERROR;
 493         }
 494     }
 495   return fd;
 496 }
 497 #undef FUNC_NAME
 498
 499
 500 SCM_DEFINE (scm_dup2, "dup2", 2, 0, 0,
 501             (SCM oldfd, SCM newfd),
 502             "A simple wrapper for the @code{dup2} system call.\n"
 503             "Copies the file descriptor @var{oldfd} to descriptor\n"
 504             "number @var{newfd}, replacing the previous meaning\n"
 505             "of @var{newfd}.  Both @var{oldfd} and @var{newfd} must\n"
 506             "be integers.\n"
 507             "Unlike for dup->fdes or primitive-move->fdes, no attempt\n"
 508             "is made to move away ports which are using @var{newfd}.\n"
 509             "The return value is unspecified.")
 510 #define FUNC_NAME s_scm_dup2
 511 {
 512   int c_oldfd;
 513   int c_newfd;
 514   int rv;
 515
 516   SCM_VALIDATE_INUM_COPY (1, oldfd, c_oldfd);
 517   SCM_VALIDATE_INUM_COPY (2, newfd, c_newfd);
 518   rv = dup2 (c_oldfd, c_newfd);
 519   if (rv == -1)
 520     SCM_SYSERROR;
 521   return SCM_UNSPECIFIED;
 522 }
 523 #undef FUNC_NAME
 524
 525 SCM_DEFINE (scm_fileno, "fileno", 1, 0, 0,
 526             (SCM port),
 527             "Returns the integer file descriptor underlying @var{port}.\n"
 528             "Does not change its revealed count.")
 529 #define FUNC_NAME s_scm_fileno
 530 {
 531   port = SCM_COERCE_OUTPORT (port);
 532   SCM_VALIDATE_OPFPORT (1,port);
 533   return SCM_MAKINUM (SCM_FPORT_FDES (port));
 534 }
 535 #undef FUNC_NAME
 536
 537 /* GJB:FIXME:: why does this not throw
 538    an error if the arg is not a port?
 539    This proc as is would be better names isattyport?
 540    if it is not going to assume that the arg is a port */
 541 SCM_DEFINE (scm_isatty_p, "isatty?", 1, 0, 0,
 542             (SCM port),
 543             "Returns @code{#t} if @var{port} is using a serial\n"
 544             "non-file device, otherwise @code{#f}.")
 545 #define FUNC_NAME s_scm_isatty_p
 546 {
 547   int rv;
 548
 549   port = SCM_COERCE_OUTPORT (port);
 550
 551   if (!SCM_OPFPORTP (port))
 552     return SCM_BOOL_F;
 553
 554   rv = isatty (SCM_FPORT_FDES (port));
 555   return  SCM_BOOL(rv);
 556 }
 557 #undef FUNC_NAME
 558
 559
 560
 561 SCM_DEFINE (scm_fdopen, "fdopen", 2, 0, 0,
 562             (SCM fdes, SCM modes),
 563             "Returns a new port based on the file descriptor @var{fdes}.\n"
 564             "Modes are given by the string @var{modes}.  The revealed count of the port\n"
 565             "is initialized to zero.  The modes string is the same as that accepted\n"
 566             "by @ref{File Ports, open-file}.")
 567 #define FUNC_NAME s_scm_fdopen
 568 {
 569   SCM_VALIDATE_INUM (1,fdes);
 570   SCM_VALIDATE_STRING (2, modes);
 571   SCM_STRING_COERCE_0TERMINATION_X (modes);
 572
 573   return scm_fdes_to_port (SCM_INUM (fdes), SCM_STRING_CHARS (modes), SCM_BOOL_F);
 574 }
 575 #undef FUNC_NAME
 576
 577
 578
 579 /* Move a port's underlying file descriptor to a given value.
 580  * Returns  #f if fdes is already the given value.
 581  *          #t if fdes moved.
 582  * MOVE->FDES is implemented in Scheme and calls this primitive.
 583  */
 584 SCM_DEFINE (scm_primitive_move_to_fdes, "primitive-move->fdes", 2, 0, 0,
 585             (SCM port, SCM fd),
 586             "Moves the underlying file descriptor for @var{port} to the integer\n"
 587             "value @var{fdes} without changing the revealed count of @var{port}.\n"
 588             "Any other ports already using this descriptor will be automatically\n"
 589             "shifted to new descriptors and their revealed counts reset to zero.\n"
 590             "The return value is @code{#f} if the file descriptor already had the\n"
 591             "required value or @code{#t} if it was moved.")
 592 #define FUNC_NAME s_scm_primitive_move_to_fdes
 593 {
 594   struct scm_fport *stream;
 595   int old_fd;
 596   int new_fd;
 597   int rv;
 598
 599   port = SCM_COERCE_OUTPORT (port);
 600
 601   SCM_VALIDATE_OPFPORT (1,port);
 602   SCM_VALIDATE_INUM (2,fd);
 603   stream = SCM_FSTREAM (port);
 604   old_fd = stream->fdes;
 605   new_fd = SCM_INUM (fd);
 606   if  (old_fd == new_fd)
 607     {
 608       return SCM_BOOL_F;
 609     }
 610   scm_evict_ports (new_fd);
 611   rv = dup2 (old_fd, new_fd);
 612   if (rv == -1)
 613     SCM_SYSERROR;
 614   stream->fdes = new_fd;
 615   SCM_SYSCALL (close (old_fd));
 616   return SCM_BOOL_T;
 617 }
 618 #undef FUNC_NAME
 619
 620 /* Return a list of ports using a given file descriptor.  */
 621 SCM_DEFINE (scm_fdes_to_ports, "fdes->ports", 1, 0, 0,
 622            (SCM fd),
 623             "Returns a list of existing ports which have @var{fdes} as an\n"
 624             "underlying file descriptor, without changing their revealed counts.")
 625 #define FUNC_NAME s_scm_fdes_to_ports
 626 {
 627   SCM result = SCM_EOL;
 628   int int_fd;
 629   int i;
 630
 631   SCM_VALIDATE_INUM_COPY (1,fd,int_fd);
 632
 633   for (i = 0; i < scm_port_table_size; i++)
 634     {
 635       if (SCM_OPFPORTP (scm_port_table[i]->port)
 636           && ((struct scm_fport *) scm_port_table[i]->stream)->fdes == int_fd)
 637         result = scm_cons (scm_port_table[i]->port, result);
 638     }
 639   return result;
 640 }
 641 #undef FUNC_NAME
 642
 643
 644 void
 645 scm_init_ioext ()
 646 {
 647   scm_add_feature ("i/o-extensions");
 648
 649 #ifndef SCM_MAGIC_SNARFER
 650 #include "libguile/ioext.x"
 651 #endif
 652 }
 653
 654
 655 /*
 656   Local Variables:
 657   c-file-style: "gnu"
 658   End:
 659 */