io.c

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/**********************************************************************

  io.c -

  $Author: akr $
  $Date: 2005/12/19 17:11:20 $
  created at: Fri Oct 15 18:08:59 JST 1993

  Copyright (C) 1993-2003 Yukihiro Matsumoto
  Copyright (C) 2000  Network Applied Communication Laboratory, Inc.
  Copyright (C) 2000  Information-technology Promotion Agency, Japan

**********************************************************************/

#if defined(__VMS)
#define _XOPEN_SOURCE
#define _POSIX_C_SOURCE 2
#endif

#include "ruby.h"
#include "rubyio.h"
#include "rubysig.h"
#include "env.h"
#include <ctype.h>
#include <errno.h>

#if defined(MSDOS) || defined(__BOW__) || defined(__CYGWIN__) || defined(_WIN32) || defined(__human68k__) || defined(__EMX__) || defined(__BEOS__)
# define NO_SAFE_RENAME
#endif

#if defined(MSDOS) || defined(__CYGWIN__) || defined(_WIN32)
# define NO_LONG_FNAME
#endif

#if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) || defined(sun) || defined(_nec_ews)
# define USE_SETVBUF
#endif

#ifdef __QNXNTO__
#include "unix.h"
#endif

#include <sys/types.h>
#if defined(HAVE_SYS_IOCTL_H) && !defined(DJGPP) && !defined(_WIN32) && !defined(__human68k__)
#include <sys/ioctl.h>
#endif
#if defined(HAVE_FCNTL_H) || defined(_WIN32)
#include <fcntl.h>
#elif defined(HAVE_SYS_FCNTL_H)
#include <sys/fcntl.h>
#endif

#if !HAVE_OFF_T && !defined(off_t)
# define off_t  long
#endif
#if !HAVE_FSEEKO && !defined(fseeko)
# define fseeko  fseek
#endif
#if !HAVE_FTELLO && !defined(ftello)
# define ftello  ftell
#endif

#include <sys/stat.h>

/* EMX has sys/param.h, but.. */
#if defined(HAVE_SYS_PARAM_H) && !(defined(__EMX__) || defined(__HIUX_MPP__))
# include <sys/param.h>
#endif

#if !defined NOFILE
# define NOFILE 64
#endif

#ifdef HAVE_UNISTD_H
#ifdef HAVE_SYSCALL_H
#include <syscall.h>
#elif defined HAVE_SYS_SYSCALL_H
#include <sys/syscall.h>
#endif

#include <unistd.h>
#endif

extern void Init_File (void);

#ifdef __BEOS__
# ifndef NOFILE
#  define NOFILE (OPEN_MAX)
# endif
#include <net/socket.h>
#endif

#include "util.h"

#ifndef O_ACCMODE
#define O_ACCMODE (O_RDONLY | O_WRONLY | O_RDWR)
#endif

#if SIZEOF_OFF_T > SIZEOF_LONG && !defined(HAVE_LONG_LONG)
# error off_t is bigger than long, but you have no long long...
#endif

#ifndef PIPE_BUF
# ifdef _POSIX_PIPE_BUF
#  define PIPE_BUF _POSIX_PIPE_BUF
# else
#  define PIPE_BUF 512 /* is this ok? */
# endif
#endif

VALUE rb_cIO;
VALUE rb_eEOFError;
VALUE rb_eIOError;

VALUE rb_stdin, rb_stdout, rb_stderr;
VALUE rb_deferr;                /* rescue VIM plugin */
static VALUE orig_stdout, orig_stderr;

VALUE rb_output_fs;
VALUE rb_rs;
VALUE rb_output_rs;
VALUE rb_default_rs;

static VALUE argf;

static ID id_write, id_read, id_getc;

extern char *ruby_inplace_mode;

struct timeval rb_time_interval (VALUE);

static VALUE filename, current_file;
static int gets_lineno;
static int init_p = 0, next_p = 0;
static VALUE lineno = INT2FIX(0);

#ifdef _STDIO_USES_IOSTREAM  /* GNU libc */
#  ifdef _IO_fpos_t
#    define READ_DATA_PENDING(fp) ((fp)->_IO_read_ptr != (fp)->_IO_read_end)
#    define READ_DATA_PENDING_COUNT(fp) ((fp)->_IO_read_end - (fp)->_IO_read_ptr)
#    define READ_DATA_PENDING_PTR(fp) ((fp)->_IO_read_ptr)
#  else
#    define READ_DATA_PENDING(fp) ((fp)->_gptr < (fp)->_egptr)
#    define READ_DATA_PENDING_COUNT(fp) ((fp)->_egptr - (fp)->_gptr)
#    define READ_DATA_PENDING_PTR(fp) ((fp)->_gptr)
#  endif
#elif defined(FILE_COUNT)
#  define READ_DATA_PENDING(fp) ((fp)->FILE_COUNT > 0)
#  define READ_DATA_PENDING_COUNT(fp) ((fp)->FILE_COUNT)
#elif defined(FILE_READEND)
#  define READ_DATA_PENDING(fp) ((fp)->FILE_READPTR < (fp)->FILE_READEND)
#  define READ_DATA_PENDING_COUNT(fp) ((fp)->FILE_READEND - (fp)->FILE_READPTR)
#elif defined(__BEOS__)
#  define READ_DATA_PENDING(fp) (fp->_state._eof == 0)
#elif defined(__VMS)
#  define READ_DATA_PENDING_COUNT(fp) ((unsigned int)(*(fp))->_cnt)
#  define READ_DATA_PENDING(fp)       (((unsigned int)(*(fp))->_cnt) > 0)
#  define READ_DATA_BUFFERED(fp) 0
#else
/* requires systems own version of the ReadDataPending() */
extern int ReadDataPending();
#  define READ_DATA_PENDING(fp) (!feof(fp))
#  define READ_DATA_BUFFERED(fp) 0
#endif
#ifndef READ_DATA_BUFFERED
#  define READ_DATA_BUFFERED(fp) READ_DATA_PENDING(fp)
#endif

#ifndef READ_DATA_PENDING_PTR
# ifdef FILE_READPTR
#  define READ_DATA_PENDING_PTR(fp) ((char *)(fp)->FILE_READPTR)
# endif
#endif

#if defined __DJGPP__
# undef READ_DATA_PENDING_COUNT
# undef READ_DATA_PENDING_PTR
#endif

#define READ_CHECK(fp) do {\
    if (!READ_DATA_PENDING(fp)) {\
        rb_thread_wait_fd(fileno(fp));\
        rb_io_check_closed(fptr);\
     }\
} while(0)

void
rb_eof_error()
{
    rb_raise(rb_eEOFError, "end of file reached");
}

VALUE
rb_io_taint_check(io)
    VALUE io;
{
    if (!OBJ_TAINTED(io) && rb_safe_level() >= 4)
        rb_raise(rb_eSecurityError, "Insecure: operation on untainted IO");
    rb_check_frozen(io);
    return io;
}

void
rb_io_check_initialized(fptr)
    OpenFile *fptr;
{
    if (!fptr) {
        rb_raise(rb_eIOError, "uninitialized stream");
    }
}

void
rb_io_check_closed(fptr)
    OpenFile *fptr;
{
    rb_io_check_initialized(fptr);
    if (!fptr->f && !fptr->f2) {
        rb_raise(rb_eIOError, "closed stream");
    }
}

static void io_fflush (FILE *, OpenFile *);

static OpenFile *
flush_before_seek(fptr)
    OpenFile *fptr;
{
    if (fptr->mode & FMODE_WBUF) {
        io_fflush(GetWriteFile(fptr), fptr);
    }
    return fptr;
}

#define io_seek(fptr, ofs, whence) fseeko(flush_before_seek(fptr)->f, ofs, whence)
#define io_tell(fptr) ftello(flush_before_seek(fptr)->f)

#ifndef SEEK_CUR
# define SEEK_SET 0
# define SEEK_CUR 1
# define SEEK_END 2
#endif

#define FMODE_SYNCWRITE (FMODE_SYNC|FMODE_WRITABLE)

void
rb_io_check_readable(fptr)
    OpenFile *fptr;
{
    rb_io_check_closed(fptr);
    if (!(fptr->mode & FMODE_READABLE)) {
        rb_raise(rb_eIOError, "not opened for reading");
    }
#if NEED_IO_SEEK_BETWEEN_RW
    if (((fptr->mode & FMODE_WBUF) ||
         (fptr->mode & (FMODE_SYNCWRITE|FMODE_RBUF)) == FMODE_SYNCWRITE) &&
        !feof(fptr->f) &&
        !fptr->f2) {
        io_seek(fptr, 0, SEEK_CUR);
    }
#endif
    fptr->mode |= FMODE_RBUF;
}

void
rb_io_check_writable(fptr)
    OpenFile *fptr;
{
    rb_io_check_closed(fptr);
    if (!(fptr->mode & FMODE_WRITABLE)) {
        rb_raise(rb_eIOError, "not opened for writing");
    }
    if ((fptr->mode & FMODE_RBUF) && !feof(fptr->f) && !fptr->f2) {
        io_seek(fptr, 0, SEEK_CUR);
    }
    if (!fptr->f2) {
        fptr->mode &= ~FMODE_RBUF;
    }
}

int
rb_read_pending(fp)
    FILE *fp;
{
    return READ_DATA_PENDING(fp);
}

void
rb_read_check(fp)
    FILE *fp;
{
    if (!READ_DATA_PENDING(fp)) {
        rb_thread_wait_fd(fileno(fp));
    }
}

static int
ruby_dup(orig)
    int orig;
{
    int fd;

    fd = dup(orig);
    if (fd < 0) {
        if (errno == EMFILE || errno == ENFILE) {
            rb_gc();
            fd = dup(orig);
        }
        if (fd < 0) {
            rb_sys_fail(0);
        }
    }
    return fd;
}

static VALUE io_alloc (VALUE);
static VALUE
io_alloc(klass)
    VALUE klass;
{
    NEWOBJ(io, struct RFile);
    OBJSETUP(io, klass, T_FILE);

    io->fptr = 0;

    return (VALUE)io;
}

static void
io_fflush(f, fptr)
    FILE *f;
    OpenFile *fptr;
{
    int n;

    if (!rb_thread_fd_writable(fileno(f))) {
        rb_io_check_closed(fptr);
    }
    for (;;) {
        TRAP_BEG;
        n = fflush(f);
        TRAP_END;
        if (n != EOF) break;
        if (!rb_io_wait_writable(fileno(f)))
            rb_sys_fail(fptr->path);
    }
    fptr->mode &= ~FMODE_WBUF;
}

int
rb_io_wait_readable(f)
    int f;
{
    fd_set rfds;

    switch (errno) {
      case EINTR:
#if defined(ERESTART)
      case ERESTART:
#endif
        rb_thread_wait_fd(f);
        return Qtrue;

      case EAGAIN:
#if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
      case EWOULDBLOCK:
#endif
        FD_ZERO(&rfds);
        FD_SET(f, &rfds);
        rb_thread_select(f + 1, &rfds, NULL, NULL, NULL);
        return Qtrue;

      default:
        return Qfalse;
    }
}

int
rb_io_wait_writable(f)
    int f;
{
    fd_set wfds;

    switch (errno) {
      case EINTR:
#if defined(ERESTART)
      case ERESTART:
#endif
        rb_thread_fd_writable(f);
        return Qtrue;

      case EAGAIN:
#if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
      case EWOULDBLOCK:
#endif
        FD_ZERO(&wfds);
        FD_SET(f, &wfds);
        rb_thread_select(f + 1, NULL, &wfds, NULL, NULL);
        return Qtrue;

      default:
        return Qfalse;
    }
}

#ifndef S_ISREG
#   define S_ISREG(m) ((m & S_IFMT) == S_IFREG)
#endif

static int
wsplit_p(OpenFile *fptr)
{
    FILE *f = GetWriteFile(fptr);
    int r;
    if (!(fptr->mode & FMODE_WSPLIT_INITIALIZED)) {
        struct stat buf;
        if (fstat(fileno(f), &buf) == 0 &&
            !S_ISREG(buf.st_mode)
#if defined(HAVE_FCNTL) && defined(F_GETFL) && defined(O_NONBLOCK)
            && (r = fcntl(fileno(f), F_GETFL)) != -1 &&
            !(r & O_NONBLOCK)
#endif
            ) {
            fptr->mode |= FMODE_WSPLIT;
        }
        fptr->mode |= FMODE_WSPLIT_INITIALIZED;
    }
    return fptr->mode & FMODE_WSPLIT;
}

/* writing functions */
static long
io_fwrite(str, fptr)
    VALUE str;
    OpenFile *fptr;
{
    long len, n, r, l, offset = 0;
    FILE *f = GetWriteFile(fptr);

    len = RSTRING(str)->len;
    if ((n = len) <= 0) return n;
    if (fptr->mode & FMODE_SYNC) {
        io_fflush(f, fptr);
        if (!rb_thread_fd_writable(fileno(f))) {
            rb_io_check_closed(fptr);
        }
      retry:
        l = n;
        if (PIPE_BUF < l &&
            !rb_thread_critical &&
            !rb_thread_alone() &&
            wsplit_p(fptr)) {
            l = PIPE_BUF;
        }
        TRAP_BEG;
        r = write(fileno(f), RSTRING(str)->ptr+offset, l);
        TRAP_END;
        if (r == n) return len;
        if (0 <= r) {
            offset += r;
            n -= r;
            errno = EAGAIN;
        }
        if (rb_io_wait_writable(fileno(f))) {
            rb_io_check_closed(fptr);
            if (offset < RSTRING(str)->len)
                goto retry;
        }
        return -1L;
    }
#if defined(__human68k__) || defined(__vms)
    do {
        if (fputc(RSTRING(str)->ptr[offset++], f) == EOF) {
            if (ferror(f)) return -1L;
            break;
        }
    } while (--n > 0);
#else
    while (errno = 0, offset += (r = fwrite(RSTRING(str)->ptr+offset, 1, n, f)), (n -= r) > 0) {
        if (ferror(f)
#if defined __BORLANDC__
            || errno
#endif
        ) {
#ifdef __hpux
            if (!errno) errno = EAGAIN;
#elif defined(_WIN32) && !defined(__BORLANDC__)
            /* workaround for MSVCRT's bug */
            if (!errno) {
                if (GetLastError() == ERROR_NO_DATA)
                    errno = EPIPE;
                else
                    errno = EBADF;
            }
#endif
            if (rb_io_wait_writable(fileno(f))) {
                rb_io_check_closed(fptr);
                clearerr(f);
                if (offset < RSTRING(str)->len)
                    continue;
            }
            return -1L;
        }
    }
#endif
    return len - n;
}

long
rb_io_fwrite(ptr, len, f)
    const char *ptr;
    long len;
    FILE *f;
{
    OpenFile of;

    of.f = f;
    of.f2 = NULL;
    of.mode = FMODE_WRITABLE;
    of.path = NULL;
    return io_fwrite(rb_str_new(ptr, len), &of);
}

/*
 *  call-seq:
 *     ios.write(string)    => integer
 *  
 *  Writes the given string to <em>ios</em>. The stream must be opened
 *  for writing. If the argument is not a string, it will be converted
 *  to a string using <code>to_s</code>. Returns the number of bytes
 *  written.
 *     
 *     count = $stdout.write( "This is a test\n" )
 *     puts "That was #{count} bytes of data"
 *     
 *  <em>produces:</em>
 *     
 *     This is a test
 *     That was 15 bytes of data
 */

static VALUE
io_write(io, str)
    VALUE io, str;
{
    OpenFile *fptr;
    long n;

    rb_secure(4);
    if (TYPE(str) != T_STRING)
        str = rb_obj_as_string(str);

    if (TYPE(io) != T_FILE) {
        /* port is not IO, call write method for it. */
        return rb_funcall(io, id_write, 1, str);
    }
    if (RSTRING(str)->len == 0) return INT2FIX(0);

    GetOpenFile(io, fptr);
    rb_io_check_writable(fptr);

    n = io_fwrite(str, fptr);
    if (n == -1L) rb_sys_fail(fptr->path);
    if (!(fptr->mode & FMODE_SYNC)) {
        fptr->mode |= FMODE_WBUF;
    }

    return LONG2FIX(n);
}

VALUE
rb_io_write(io, str)
    VALUE io, str;
{
    return rb_funcall(io, id_write, 1, str);
}

/*
 *  call-seq:
 *     ios << obj     => ios
 *  
 *  String Output---Writes <i>obj</i> to <em>ios</em>.
 *  <i>obj</i> will be converted to a string using
 *  <code>to_s</code>.
 *     
 *     $stdout << "Hello " << "world!\n"
 *     
 *  <em>produces:</em>
 *     
 *     Hello world!
 */

VALUE
rb_io_addstr(io, str)
    VALUE io, str;
{
    rb_io_write(io, str);
    return io;
}

/*
 *  call-seq:
 *     ios.flush    => ios
 *  
 *  Flushes any buffered data within <em>ios</em> to the underlying
 *  operating system (note that this is Ruby internal buffering only;
 *  the OS may buffer the data as well).
 *     
 *     $stdout.print "no newline"
 *     $stdout.flush
 *     
 *  <em>produces:</em>
 *     
 *     no newline
 */

static VALUE
rb_io_flush(io)
    VALUE io;
{
    OpenFile *fptr;
    FILE *f;

    GetOpenFile(io, fptr);
    rb_io_check_writable(fptr);
    f = GetWriteFile(fptr);

    io_fflush(f, fptr);

    return io;
}

/*
 *  call-seq:
 *     ios.pos     => integer
 *     ios.tell    => integer
 *  
 *  Returns the current offset (in bytes) of <em>ios</em>.
 *     
 *     f = File.new("testfile")
 *     f.pos    #=> 0
 *     f.gets   #=> "This is line one\n"
 *     f.pos    #=> 17
 */

static VALUE
rb_io_tell(io)
     VALUE io;
{
    OpenFile *fptr;
    off_t pos;

    GetOpenFile(io, fptr);
    pos = io_tell(fptr);
    if (pos < 0) rb_sys_fail(fptr->path);
    return OFFT2NUM(pos);
}

static VALUE
rb_io_seek(io, offset, whence)
    VALUE io, offset;
    int whence;
{
    OpenFile *fptr;
    off_t pos;

    pos = NUM2OFFT(offset);
    GetOpenFile(io, fptr);
    pos = io_seek(fptr, pos, whence);
    if (pos < 0) rb_sys_fail(fptr->path);
    clearerr(fptr->f);

    return INT2FIX(0);
}

/*
 *  call-seq:
 *     ios.seek(amount, whence=SEEK_SET) -> 0
 *  
 *  Seeks to a given offset <i>anInteger</i> in the stream according to
 *  the value of <i>whence</i>:
 *
 *    IO::SEEK_CUR  | Seeks to _amount_ plus current position
 *    --------------+----------------------------------------------------
 *    IO::SEEK_END  | Seeks to _amount_ plus end of stream (you probably 
 *                  | want a negative value for _amount_)
 *    --------------+----------------------------------------------------
 *    IO::SEEK_SET  | Seeks to the absolute location given by _amount_
 *
 *  Example:
 *     
 *     f = File.new("testfile")
 *     f.seek(-13, IO::SEEK_END)   #=> 0
 *     f.readline                  #=> "And so on...\n"
 */

static VALUE
rb_io_seek_m(argc, argv, io)
    int argc;
    VALUE *argv;
    VALUE io;
{
    VALUE offset, ptrname;
    int whence = SEEK_SET;

    if (rb_scan_args(argc, argv, "11", &offset, &ptrname) == 2) {
        whence = NUM2INT(ptrname);
    }

    return rb_io_seek(io, offset, whence);
}

/*
 *  call-seq:
 *     ios.pos = integer    => integer
 *  
 *  Seeks to the given position (in bytes) in <em>ios</em>.
 *     
 *     f = File.new("testfile")
 *     f.pos = 17
 *     f.gets   #=> "This is line two\n"
 */

static VALUE
rb_io_set_pos(io, offset)
     VALUE io, offset;
{
    OpenFile *fptr;
    off_t pos;

    pos = NUM2OFFT(offset);
    GetOpenFile(io, fptr);
    pos = io_seek(fptr, pos, SEEK_SET);
    if (pos != 0) rb_sys_fail(fptr->path);
    clearerr(fptr->f);

    return OFFT2NUM(pos);
}

/*
 *  call-seq:
 *     ios.rewind    => 0
 *  
 *  Positions <em>ios</em> to the beginning of input, resetting
 *  <code>lineno</code> to zero.
 *     
 *     f = File.new("testfile")
 *     f.readline   #=> "This is line one\n"
 *     f.rewind     #=> 0
 *     f.lineno     #=> 0
 *     f.readline   #=> "This is line one\n"
 */

static VALUE
rb_io_rewind(io)
    VALUE io;
{
    OpenFile *fptr;

    GetOpenFile(io, fptr);
    if (io_seek(fptr, 0L, 0) != 0) rb_sys_fail(fptr->path);
    clearerr(fptr->f);
    if (io == current_file) {
        gets_lineno -= fptr->lineno;
    }
    fptr->lineno = 0;

    return INT2FIX(0);
}

/*
 *  call-seq:
 *     ios.eof     => true or false
 *     ios.eof?    => true or false
 *
 *  Returns true if <em>ios</em> is at end of file that means
 *  there are no more data to read.
 *  The stream must be opened for reading or an <code>IOError</code> will be
 *  raised.
 *
 *     f = File.new("testfile")
 *     dummy = f.readlines
 *     f.eof   #=> true
 *
 *  If <em>ios</em> is a stream such as pipe or socket, <code>IO#eof?</code>
 *  blocks until the other end sends some data or closes it.
 *
 *     r, w = IO.pipe
 *     Thread.new { sleep 1; w.close }
 *     r.eof?  #=> true after 1 second blocking
 *
 *     r, w = IO.pipe
 *     Thread.new { sleep 1; w.puts "a" }
 *     r.eof?  #=> false after 1 second blocking
 *
 *     r, w = IO.pipe
 *     r.eof?  # blocks forever
 *
 *  Note that <code>IO#eof?</code> reads data to a input buffer.
 *  So <code>IO#sysread</code> doesn't work with <code>IO#eof?</code>.
 */

VALUE
rb_io_eof(io)
    VALUE io;
{
    OpenFile *fptr;
    int ch;

    GetOpenFile(io, fptr);
    rb_io_check_readable(fptr);

    if (feof(fptr->f)) return Qtrue;
    if (READ_DATA_PENDING(fptr->f)) return Qfalse;
    READ_CHECK(fptr->f);
    clearerr(fptr->f);
    TRAP_BEG;
    ch = getc(fptr->f);
    TRAP_END;

    if (ch != EOF) {
        ungetc(ch, fptr->f);
        return Qfalse;
    }
    rb_io_check_closed(fptr);
    clearerr(fptr->f);
    return Qtrue;
}

/*
 *  call-seq:
 *     ios.sync    => true or false
 *  
 *  Returns the current ``sync mode'' of <em>ios</em>. When sync mode is
 *  true, all output is immediately flushed to the underlying operating
 *  system and is not buffered by Ruby internally. See also
 *  <code>IO#fsync</code>.
 *     
 *     f = File.new("testfile")
 *     f.sync   #=> false
 */

static VALUE
rb_io_sync(io)
    VALUE io;
{
    OpenFile *fptr;

    GetOpenFile(io, fptr);
    return (fptr->mode & FMODE_SYNC) ? Qtrue : Qfalse;
}

/*
 *  call-seq:
 *     ios.sync = boolean   => boolean
 *  
 *  Sets the ``sync mode'' to <code>true</code> or <code>false</code>.
 *  When sync mode is true, all output is immediately flushed to the
 *  underlying operating system and is not buffered internally. Returns
 *  the new state. See also <code>IO#fsync</code>.
 *     
 *     f = File.new("testfile")
 *     f.sync = true
 *     
 *  <em>(produces no output)</em>
 */

static VALUE
rb_io_set_sync(io, mode)
    VALUE io, mode;
{
    OpenFile *fptr;

    GetOpenFile(io, fptr);
    if (RTEST(mode)) {
        fptr->mode |= FMODE_SYNC;
    }
    else {
        fptr->mode &= ~FMODE_SYNC;
    }
    return mode;
}

/*
 *  call-seq:
 *     ios.fsync   => 0 or nil
 *  
 *  Immediately writes all buffered data in <em>ios</em> to disk.
 *  Returns <code>nil</code> if the underlying operating system does not
 *  support <em>fsync(2)</em>. Note that <code>fsync</code> differs from
 *  using <code>IO#sync=</code>. The latter ensures that data is flushed
 *  from Ruby's buffers, but doesn't not guarantee that the underlying
 *  operating system actually writes it to disk.
 */

static VALUE
rb_io_fsync(io)
    VALUE io;
{
#ifdef HAVE_FSYNC
    OpenFile *fptr;
    FILE *f;

    GetOpenFile(io, fptr);
    f = GetWriteFile(fptr);

    io_fflush(f, fptr);
    if (fsync(fileno(f)) < 0)
        rb_sys_fail(fptr->path);
    return INT2FIX(0);
#else
    rb_notimplement();
    return Qnil;                /* not reached */
#endif
}

/*
 *  call-seq:
 *     ios.fileno    => fixnum
 *     ios.to_i      => fixnum
 *  
 *  Returns an integer representing the numeric file descriptor for
 *  <em>ios</em>.
 *     
 *     $stdin.fileno    #=> 0
 *     $stdout.fileno   #=> 1
 */

static VALUE
rb_io_fileno(io)
    VALUE io;
{
    OpenFile *fptr;
    int fd;

    GetOpenFile(io, fptr);
    fd = fileno(fptr->f);
    return INT2FIX(fd);
}

/*
 *  call-seq:
 *     ios.pid    => fixnum
 *  
 *  Returns the process ID of a child process associated with
 *  <em>ios</em>. This will be set by <code>IO::popen</code>.
 *     
 *     pipe = IO.popen("-")
 *     if pipe
 *       $stderr.puts "In parent, child pid is #{pipe.pid}"
 *     else
 *       $stderr.puts "In child, pid is #{$$}"
 *     end
 *     
 *  <em>produces:</em>
 *     
 *     In child, pid is 26209
 *     In parent, child pid is 26209
 */

static VALUE
rb_io_pid(io)
    VALUE io;
{
    OpenFile *fptr;

    GetOpenFile(io, fptr);
    if (!fptr->pid)
        return Qnil;
    return INT2FIX(fptr->pid);
}

/*
 * call-seq:
 *   ios.inspect   => string
 *
 * Return a string describing this IO object.
 */

static VALUE
rb_io_inspect(obj)
    VALUE obj;
{
    OpenFile *fptr;
    char *buf, *cname, *st = "";
    long len;

    fptr = RFILE(rb_io_taint_check(obj))->fptr;
    if (!fptr || !fptr->path) return rb_any_to_s(obj);
    cname = rb_obj_classname(obj);
    len = strlen(cname) + strlen(fptr->path) + 5;
    if (!(fptr->f || fptr->f2)) {
        st = " (closed)";
        len += 9;
    }
    buf = ALLOCA_N(char, len);
    snprintf(buf, len, "#<%s:%s%s>", cname, fptr->path, st);
    return rb_str_new2(buf);
}

/*
 *  call-seq:
 *     ios.to_io -> ios
 *  
 *  Returns <em>ios</em>.
 */

static VALUE
rb_io_to_io(io)
    VALUE io;
{
    return io;
}

/* reading functions */
static long
read_buffered_data(ptr, len, f)
    char *ptr;
    long len;
    FILE *f;
{
    long n;

#ifdef READ_DATA_PENDING_COUNT
    n = READ_DATA_PENDING_COUNT(f);
    if (n <= 0) return 0;
    if (n > len) n = len;
    return fread(ptr, 1, n, f);
#else
    int c;

    for (n = 0; n < len && READ_DATA_PENDING(f) && (c = getc(f)) != EOF; ++n) {
        *ptr++ = c;
    }
    return n;
#endif
}

long
io_fread(ptr, len, fptr)
    char *ptr;
    long len;
    OpenFile *fptr;
{
    long n = len;
    int c;
    int saved_errno;

    while (n > 0) {
        c = read_buffered_data(ptr, n, fptr->f);
        if (c < 0) goto eof;
        if (c > 0) {
            ptr += c;
            if ((n -= c) <= 0) break;
        }
        rb_thread_wait_fd(fileno(fptr->f));
        rb_io_check_closed(fptr);
        clearerr(fptr->f);
        TRAP_BEG;
        c = getc(fptr->f);
        TRAP_END;
        if (c == EOF) {
          eof:
            if (ferror(fptr->f)) {
                switch (errno) {
                  case EINTR:
#if defined(ERESTART)
                  case ERESTART:
#endif
                    clearerr(fptr->f);
                    continue;
                  case EAGAIN:
#if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
                  case EWOULDBLOCK:
#endif
                    if (len > n) {
                        clearerr(fptr->f);
                    }
                    saved_errno = errno;
                    rb_warning("nonblocking IO#read is obsolete; use IO#readpartial or IO#sysread");
                    errno = saved_errno;
                }
                if (len == n) return 0;
            }
            break;
        }
        *ptr++ = c;
        n--;
    }
    return len - n;
}

long
rb_io_fread(ptr, len, f)
    char *ptr;
    long len;
    FILE *f;
{
    OpenFile of;

    of.f = f;
    of.f2 = NULL;
    return io_fread(ptr, len, &of);
}

#define SMALLBUF 100

static long
remain_size(fptr)
    OpenFile *fptr;
{
    struct stat st;
    off_t siz = BUFSIZ;
    off_t pos;

    if (feof(fptr->f)) return 0;
    if (fstat(fileno(fptr->f), &st) == 0  && S_ISREG(st.st_mode)
#ifdef __BEOS__
        && (st.st_dev > 3)
#endif
        )
    {
        pos = io_tell(fptr);
        if (st.st_size >= pos && pos >= 0) {
            siz = st.st_size - pos + 1;
            if (siz > LONG_MAX) {
                rb_raise(rb_eIOError, "file too big for single read");
            }
        }
    }
    return (long)siz;
}

static VALUE
read_all(fptr, siz, str)
    OpenFile *fptr;
    long siz;
    VALUE str;
{
    long bytes = 0;
    long n;

    if (siz == 0) siz = BUFSIZ;
    if (NIL_P(str)) {
        str = rb_str_new(0, siz);
    }
    else {
        rb_str_resize(str, siz);
    }
    for (;;) {
        rb_str_locktmp(str);
        READ_CHECK(fptr->f);
        n = io_fread(RSTRING(str)->ptr+bytes, siz-bytes, fptr);
        rb_str_unlocktmp(str);
        if (n == 0 && bytes == 0) {
            if (!fptr->f) break;
            if (feof(fptr->f)) break;
            if (!ferror(fptr->f)) break;
            rb_sys_fail(fptr->path);
        }
        bytes += n;
        if (bytes < siz) break;
        siz += BUFSIZ;
        rb_str_resize(str, siz);
    }
    if (bytes != siz) rb_str_resize(str, bytes);
    OBJ_TAINT(str);

    return str;
}

static VALUE
io_getpartial(int argc, VALUE *argv, VALUE io)
{
    OpenFile *fptr;
    VALUE length, str;
    long n, len;

    rb_scan_args(argc, argv, "11", &length, &str);

    if ((len = NUM2LONG(length)) < 0) {
        rb_raise(rb_eArgError, "negative length %ld given", len);
    }

    if (NIL_P(str)) {
        str = rb_str_new(0, len);
    }
    else {
        StringValue(str);
        rb_str_modify(str);
        rb_str_resize(str, len);
    }
    OBJ_TAINT(str);

    GetOpenFile(io, fptr);
    rb_io_check_readable(fptr);

    if (len == 0)
        return str;

    READ_CHECK(fptr->f);
    if (RSTRING(str)->len != len) {
      modified:
        rb_raise(rb_eRuntimeError, "buffer string modified");
    }
    n = read_buffered_data(RSTRING(str)->ptr, len, fptr->f);
    if (n <= 0) {
      again:
        if (RSTRING(str)->len != len) goto modified;
        TRAP_BEG;
        n = read(fileno(fptr->f), RSTRING(str)->ptr, len);
        TRAP_END;
        if (n < 0) {
            if (rb_io_wait_readable(fileno(fptr->f)))
                goto again;
            rb_sys_fail(fptr->path);
        }
    }
    rb_str_resize(str, n);

    if (n == 0)
        return Qnil;
    else
        return str;
}

/*
 *  call-seq:
 *     ios.readpartial(maxlen[, outbuf])    => string, outbuf
 *
 *  Reads at most <i>maxlen</i> bytes from the I/O stream but
 *  it blocks only if <em>ios</em> has no data immediately available.
 *  If the optional <i>outbuf</i> argument is present,
 *  it must reference a String, which will receive the data.
 *  It raises <code>EOFError</code> on end of file.
 *
 *  readpartial is designed for streams such as pipe, socket, tty, etc.
 *  It blocks only when no data immediately available.
 *  This means that it blocks only when following all conditions hold.
 *  * the buffer in the IO object is empty.
 *  * the content of the stream is empty.
 *  * the stream is not reached to EOF.
 *
 *  When readpartial blocks, it waits data or EOF on the stream.
 *  If some data is reached, readpartial returns with the data.
 *  If EOF is reached, readpartial raises EOFError.
 *
 *  When readpartial doesn't blocks, it returns or raises immediately.
 *  If the buffer is not empty, it returns the data in the buffer.
 *  Otherwise if the stream has some content,
 *  it returns the data in the stream. 
 *  Otherwise if the stream is reached to EOF, it raises EOFError.
 *
 *     r, w = IO.pipe           #               buffer          pipe content
 *     w << "abc"               #               ""              "abc".
 *     r.readpartial(4096)      #=> "abc"       ""              ""
 *     r.readpartial(4096)      # blocks because buffer and pipe is empty.
 *
 *     r, w = IO.pipe           #               buffer          pipe content
 *     w << "abc"               #               ""              "abc"
 *     w.close                  #               ""              "abc" EOF
 *     r.readpartial(4096)      #=> "abc"       ""              EOF
 *     r.readpartial(4096)      # raises EOFError
 *
 *     r, w = IO.pipe           #               buffer          pipe content
 *     w << "abc\ndef\n"        #               ""              "abc\ndef\n"
 *     r.gets                   #=> "abc\n"     "def\n"         ""
 *     w << "ghi\n"             #               "def\n"         "ghi\n"
 *     r.readpartial(4096)      #=> "def\n"     ""              "ghi\n"
 *     r.readpartial(4096)      #=> "ghi\n"     ""              ""
 *
 *  Note that readpartial is nonblocking-flag insensitive.
 *  It blocks even if the nonblocking-flag is set.
 *
 *  Also note that readpartial behaves similar to sysread in blocking mode.
 *  The behavior is identical when the buffer is empty.
 *
 */

static VALUE
io_readpartial(int argc, VALUE *argv, VALUE io)
{
    VALUE ret;

    ret = io_getpartial(argc, argv, io);
    if (NIL_P(ret))
        rb_eof_error();
    else
        return ret;
}

/*
 *  call-seq:
 *     ios.read([length [, buffer]])    => string, buffer, or nil
 *
 *  Reads at most <i>length</i> bytes from the I/O stream, or to the
 *  end of file if <i>length</i> is omitted or is <code>nil</code>.
 *  <i>length</i> must be a non-negative integer or nil.
 *  If the optional <i>buffer</i> argument is present, it must reference
 *  a String, which will receive the data.
 *
 *  At end of file, it returns <code>nil</code> or <code>""</code>
 *  depend on <i>length</i>.
 *  <code><i>ios</i>.read()</code> and
 *  <code><i>ios</i>.read(nil)</code> returns <code>""</code>.
 *  <code><i>ios</i>.read(<i>positive-integer</i>)</code> returns nil.
 *
 *     f = File.new("testfile")
 *     f.read(16)   #=> "This is line one"
 */

static VALUE
io_read(argc, argv, io)
    int argc;
    VALUE *argv;
    VALUE io;
{
    OpenFile *fptr;
    long n, len;
    VALUE length, str;

    rb_scan_args(argc, argv, "02", &length, &str);

    if (NIL_P(length)) {
        if (!NIL_P(str)) StringValue(str);
        GetOpenFile(io, fptr);
        rb_io_check_readable(fptr);     
        return read_all(fptr, remain_size(fptr), str);
    }
    len = NUM2LONG(length);
    if (len < 0) {
        rb_raise(rb_eArgError, "negative length %ld given", len);
    }

    if (NIL_P(str)) {
        str = rb_tainted_str_new(0, len);
    }
    else {
        StringValue(str);
        rb_str_modify(str);
        rb_str_resize(str,len);
    }

    GetOpenFile(io, fptr);
    rb_io_check_readable(fptr);
    if (feof(fptr->f)) return Qnil;
    if (len == 0) return str;

    rb_str_locktmp(str);
    READ_CHECK(fptr->f);
    if (RSTRING(str)->len != len) {
        rb_raise(rb_eRuntimeError, "buffer string modified");
    }
    n = io_fread(RSTRING(str)->ptr, len, fptr);
    rb_str_unlocktmp(str);
    if (n == 0) {
        if (!fptr->f) return Qnil;
        if (feof(fptr->f)) {
            rb_str_resize(str, 0);
            return Qnil;
        }
        if (len > 0) rb_sys_fail(fptr->path);
    }
    rb_str_resize(str, n);
    RSTRING(str)->len = n;
    RSTRING(str)->ptr[n] = '\0';
    OBJ_TAINT(str);

    return str;
}

static int
appendline(fptr, delim, strp)
    OpenFile *fptr;
    int delim;
    VALUE *strp;
{
    FILE *f = fptr->f;
    VALUE str = *strp;
    int c = EOF;
#ifndef READ_DATA_PENDING_PTR
    char buf[8192];
    char *bp = buf, *bpe = buf + sizeof buf - 3;
    int update = Qfalse;
#endif

    do {
#ifdef READ_DATA_PENDING_PTR
        long pending = READ_DATA_PENDING_COUNT(f);
        if (pending > 0) {
            const char *p = READ_DATA_PENDING_PTR(f);
            const char *e = memchr(p, delim, pending);
            long last = 0, len = (c != EOF);
            if (e) pending = e - p + 1;
            len += pending;
            if (!NIL_P(str)) {
                last = RSTRING(str)->len;
                rb_str_resize(str, last + len);
            }
            else {
                *strp = str = rb_str_buf_new(len);
                RSTRING(str)->len = len;
                RSTRING(str)->ptr[len] = '\0';
            }
            if (c != EOF) {
                RSTRING(str)->ptr[last++] = c;
            }
            fread(RSTRING(str)->ptr + last, 1, pending, f); /* must not fail */
            if (e) return delim;
        }
        else if (c != EOF) {
            if (!NIL_P(str)) {
                char ch = c;
                rb_str_buf_cat(str, &ch, 1);
            }
            else {
                *strp = str = rb_str_buf_new(1);
                RSTRING(str)->ptr[RSTRING(str)->len++] = c;
            }
        }
        rb_thread_wait_fd(fileno(f));
        rb_io_check_closed(fptr);
#else
        READ_CHECK(f);
#endif
        clearerr(f);
        TRAP_BEG;
        c = getc(f);
        TRAP_END;
        if (c == EOF) {
            if (ferror(f)) {
                clearerr(f);
                if (!rb_io_wait_readable(fileno(f)))
                    rb_sys_fail(fptr->path);
                continue;
            }
#ifdef READ_DATA_PENDING_PTR
            return c;
#endif
        }
#ifndef READ_DATA_PENDING_PTR
        if (c == EOF || (*bp++ = c) == delim || bp == bpe) {
            int cnt = bp - buf;

            if (cnt > 0) {
                if (!NIL_P(str))
                    rb_str_cat(str, buf, cnt);
                else
                    *strp = str = rb_str_new(buf, cnt);
            }
            if (c == EOF) {
                if (update)
                    return (int)RSTRING(str)->ptr[RSTRING(str)->len-1];
                return c;
            }
            bp = buf;
        }
        update = Qtrue;
#endif
    } while (c != delim);

#ifdef READ_DATA_PENDING_PTR
    {
        char ch = c;
        if (!NIL_P(str)) {
            rb_str_cat(str, &ch, 1);
        }
        else {
            *strp = str = rb_str_new(&ch, 1);
        }
    }
#endif

    return c;
}

static inline int
swallow(fptr, term)
    OpenFile *fptr;
    int term;
{
    FILE *f = fptr->f;
    int c;

    do {
#ifdef READ_DATA_PENDING_PTR
        long cnt;
        while ((cnt = READ_DATA_PENDING_COUNT(f)) > 0) {
            char buf[1024];
            const char *p = READ_DATA_PENDING_PTR(f);
            int i;
            if (cnt > sizeof buf) cnt = sizeof buf;
            if (*p != term) return Qtrue;
            i = cnt;
            while (--i && *++p == term);
            if (!fread(buf, 1, cnt - i, f)) /* must not fail */
                rb_sys_fail(fptr->path);
        }
        rb_thread_wait_fd(fileno(f));
        rb_io_check_closed(fptr);
#else
        READ_CHECK(f);
#endif
        clearerr(f);
        TRAP_BEG;
        c = getc(f);
        TRAP_END;
        if (c != term) {
            ungetc(c, f);
            return Qtrue;
        }
    } while (c != EOF);
    return Qfalse;
}

static VALUE
rb_io_getline_fast(fptr, delim)
    OpenFile *fptr;
    unsigned char delim;
{
    VALUE str = Qnil;
    int c;

    while ((c = appendline(fptr, delim, &str)) != EOF && c != delim);

    if (!NIL_P(str)) {
        fptr->lineno++;
        lineno = INT2FIX(fptr->lineno);
        OBJ_TAINT(str);
    }

    return str;
}

static int
rscheck(rsptr, rslen, rs)
    char *rsptr;
    long rslen;
    VALUE rs;
{
    if (RSTRING(rs)->ptr != rsptr && RSTRING(rs)->len != rslen)
        rb_raise(rb_eRuntimeError, "rs modified");
    return 1;
}

static VALUE rb_io_getline(VALUE rs, VALUE io);

static VALUE
rb_io_getline(rs, io)
    VALUE rs, io;
{
    VALUE str = Qnil;
    OpenFile *fptr;

    GetOpenFile(io, fptr);
    rb_io_check_readable(fptr);
    if (NIL_P(rs)) {
        str = read_all(fptr, 0, Qnil);
        if (RSTRING(str)->len == 0) return Qnil;
    }
    else if (rs == rb_default_rs) {
        return rb_io_getline_fast(fptr, '\n');
    }
    else {
        int c, newline;
        char *rsptr;
        long rslen;
        int rspara = 0;

        rslen = RSTRING(rs)->len;
        if (rslen == 0) {
            rsptr = "\n\n";
            rslen = 2;
            rspara = 1;
            swallow(fptr, '\n');
        }
        else if (rslen == 1) {
            return rb_io_getline_fast(fptr, (unsigned char)RSTRING(rs)->ptr[0]);
        }
        else {
            rsptr = RSTRING(rs)->ptr;
        }
        newline = rsptr[rslen - 1];

        while ((c = appendline(fptr, newline, &str)) != EOF &&
               (c != newline || RSTRING(str)->len < rslen ||
                (rspara || rscheck(rsptr,rslen,rs), 0) ||
                memcmp(RSTRING(str)->ptr+RSTRING(str)->len-rslen,rsptr,rslen)));

        if (rspara) {
            if (c != EOF) {
                swallow(fptr, '\n');
            }
        }
    }

    if (!NIL_P(str)) {
        fptr->lineno++;
        lineno = INT2FIX(fptr->lineno);
        OBJ_TAINT(str);
    }

    return str;
}

VALUE
rb_io_gets(io)
    VALUE io;
{
    OpenFile *fptr;

    GetOpenFile(io, fptr);
    rb_io_check_readable(fptr);
    return rb_io_getline_fast(fptr, '\n');
}

/*
 *  call-seq:
 *     ios.gets(sep_string=$/)   => string or nil
 *  
 *  Reads the next ``line'' from the I/O stream; lines are separated by
 *  <i>sep_string</i>. A separator of <code>nil</code> reads the entire
 *  contents, and a zero-length separator reads the input a paragraph at
 *  a time (two successive newlines in the input separate paragraphs).
 *  The stream must be opened for reading or an <code>IOError</code>
 *  will be raised. The line read in will be returned and also assigned
 *  to <code>$_</code>. Returns <code>nil</code> if called at end of
 *  file.
 *     
 *     File.new("testfile").gets   #=> "This is line one\n"
 *     $_                          #=> "This is line one\n"
 */

static VALUE
rb_io_gets_m(argc, argv, io)
    int argc;
    VALUE *argv;
    VALUE io;
{
    VALUE rs, str;

    if (argc == 0) {
        rs = rb_rs;
    }
    else {
        rb_scan_args(argc, argv, "1", &rs);
        if (!NIL_P(rs)) StringValue(rs);
    }
    str = rb_io_getline(rs, io);
    rb_lastline_set(str);

    return str;
}

/*
 *  call-seq:
 *     ios.lineno    => integer
 *  
 *  Returns the current line number in <em>ios</em>. The stream must be
 *  opened for reading. <code>lineno</code> counts the number of times
 *  <code>gets</code> is called, rather than the number of newlines
 *  encountered. The two values will differ if <code>gets</code> is
 *  called with a separator other than newline. See also the
 *  <code>$.</code> variable.
 *     
 *     f = File.new("testfile")
 *     f.lineno   #=> 0
 *     f.gets     #=> "This is line one\n"
 *     f.lineno   #=> 1
 *     f.gets     #=> "This is line two\n"
 *     f.lineno   #=> 2
 */

static VALUE
rb_io_lineno(io)
    VALUE io;
{
    OpenFile *fptr;

    GetOpenFile(io, fptr);
    rb_io_check_readable(fptr);
    return INT2NUM(fptr->lineno);
}

/*
 *  call-seq:
 *     ios.lineno = integer    => integer
 *  
 *  Manually sets the current line number to the given value.
 *  <code>$.</code> is updated only on the next read.
 *     
 *     f = File.new("testfile")
 *     f.gets                     #=> "This is line one\n"
 *     $.                         #=> 1
 *     f.lineno = 1000
 *     f.lineno                   #=> 1000
 *     $. # lineno of last read   #=> 1
 *     f.gets                     #=> "This is line two\n"
 *     $. # lineno of last read   #=> 1001
 */

static VALUE
rb_io_set_lineno(io, lineno)
    VALUE io, lineno;
{
    OpenFile *fptr;

    GetOpenFile(io, fptr);
    rb_io_check_readable(fptr);
    fptr->lineno = NUM2INT(lineno);
    return lineno;
}

static void
lineno_setter(val, id, var)
    VALUE val;
    ID id;
    VALUE *var;
{
    gets_lineno = NUM2INT(val);
    *var = INT2FIX(gets_lineno);
}

static VALUE
argf_set_lineno(argf, val)
    VALUE argf, val;
{
    gets_lineno = NUM2INT(val);
    lineno = INT2FIX(gets_lineno);
    return Qnil;
}

static VALUE
argf_lineno()
{
    return lineno;
}

/*
 *  call-seq:
 *     ios.readline(sep_string=$/)   => string
 *  
 *  Reads a line as with <code>IO#gets</code>, but raises an
 *  <code>EOFError</code> on end of file.
 */

static VALUE
rb_io_readline(argc, argv, io)
    int argc;
    VALUE *argv;
    VALUE io;
{
    VALUE line = rb_io_gets_m(argc, argv, io);

    if (NIL_P(line)) {
        rb_eof_error();
    }
    return line;
}

/*
 *  call-seq:
 *     ios.readlines(sep_string=$/)  =>   array
 *  
 *  Reads all of the lines in <em>ios</em>, and returns them in
 *  <i>anArray</i>. Lines are separated by the optional
 *  <i>sep_string</i>. If <i>sep_string</i> is <code>nil</code>, the
 *  rest of the stream is returned as a single record.
 *  The stream must be opened for reading or an
 *  <code>IOError</code> will be raised.
 *     
 *     f = File.new("testfile")
 *     f.readlines[0]   #=> "This is line one\n"
 */

static VALUE
rb_io_readlines(argc, argv, io)
    int argc;
    VALUE *argv;
    VALUE io;
{
    VALUE line, ary;
    VALUE rs;

    if (argc == 0) {
        rs = rb_rs;
    }
    else {
        rb_scan_args(argc, argv, "1", &rs);
        if