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BIO_s_fd(3)
NAME
  BIO_s_fd, BIO_set_fd, BIO_get_fd, BIO_new_fd - File descriptor BIO

SYNOPSIS
  #include <openssl/bio.h>

  BIO_METHOD *	  BIO_s_fd(
	  void );

       #define BIO_set_fd(b,fd,c)      BIO_int_ctrl(b,BIO_C_SET_FD,c,fd)
       #define BIO_get_fd(b,c) BIO_ctrl(b,BIO_C_GET_FD,0,(char *)c)

  BIO *BIO_new_fd(
	  int fd,
	  int close_flag );

DESCRIPTION
  The BIO_s_fd() function returns the file descriptor BIO method. This is a
  wrapper around the platform's file descriptor routines, such as read() and
  write().

  The BIO_read() and BIO_write() functions read or write the underlying
  descriptor.  BIO_puts() is supported, but BIO_gets() is not.

  If the close flag is set then then close() is called on the underlying file
  descriptor when the BIO is freed.

  The BIO_reset() function attempts to change the file pointer to the start
  of file using lseek(fd, 0, 0).

  The BIO_seek() function sets the file pointer to position ofs from start of
  file using lseek(fd, ofs, 0).

  The BIO_tell() function returns the current file position by calling
  lseek(fd, 0, 1).

  The BIO_set_fd() function sets the file descriptor of BIO b to fd and the
  close flag to c.

  The BIO_get_fd() function places the file descriptor in c if it is not
  NULL. It also returns the file descriptor.  If c is not NULL it should be
  of type (int *).

  The BIO_new_fd() function returns a file descriptor BIO using fd and
  close_flag.

NOTES
  The behavior of the BIO_read() and BIO_write() functions depends on the
  behavior of the platform's read() and write() calls on the descriptor. If
  the underlying  file descriptor is in a nonblocking mode then the BIO will
  behave in the manner described in the BIO_read(3) and	 BIO_should_retry(3)
  reference pages.

  File descriptor BIOs should not be used for socket I/O. Use socket BIOs
  instead.

RETURN VALUES
  BIO_s_fd() returns the file descriptor BIO method.

  BIO_reset() returns zero for success and -1 if an error occurred.
  BIO_seek() and BIO_tell() return the current file position or -1 is an
  error occurred. These values reflect the underlying lseek() behavior.

  BIO_set_fd() always returns 1.

  BIO_get_fd() returns the file descriptor or -1 if the BIO has not been
  initialized.

  BIO_new_fd() returns the newly allocated BIO or NULL is an error occurred.

EXAMPLES
  This is a file descriptor BIO version of "Hello World":

       BIO *out;
       out = BIO_new_fd(fileno(stdout), BIO_NOCLOSE);
       BIO_printf(out, "Hello World\n");
       BIO_free(out);

SEE ALSO
  Functions: BIO_seek(3), BIO_tell(3), BIO_reset(3), BIO_read(3),
  BIO_write(3), BIO_puts(3), BIO_gets(3), BIO_printf(3), BIO_set_close(3),
  BIO_get_close(3)

Index for Section 3

Alphabetical listing for B

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