openssl/doc/crypto/BIO_s_file.pod
Richard Levitte 8eec1389fb BIO_seed() and BIO_tell() were documented in two other documents,
which is redundant.  They are now in their own document.

Also, in the name section, all the functions described shoud be
enumerated.  This will also make it much simpler to generate softlinks
name like each function to man-pages containing the info.
2000-09-14 20:24:56 +00:00

119 lines
3.3 KiB
Text

=pod
=head1 NAME
BIO_s_file, BIO_new_file, BIO_new_fp, BIO_set_fp, BIO_get_fp,
BIO_read_filename, BIO_write_filename, BIO_append_filename,
BIO_rw_filename - FILE bio
=head1 SYNOPSIS
#include <openssl/bio.h>
BIO_METHOD * BIO_s_file(void);
BIO *BIO_new_file(const char *filename, const char *mode);
BIO *BIO_new_fp(FILE *stream, int flags);
BIO_set_fp(BIO *b,FILE *fp, int flags);
BIO_get_fp(BIO *b,FILE **fpp);
int BIO_read_filename(BIO *b, char *name)
int BIO_write_filename(BIO *b, char *name)
int BIO_append_filename(BIO *b, char *name)
int BIO_rw_filename(BIO *b, char *name)
=head1 DESCRIPTION
BIO_s_file() returns the BIO file method. As its name implies it
is a wrapper round the stdio FILE structure and it is a
source/sink BIO.
Calls to BIO_read() and BIO_write() read and write data to the
underlying stream. BIO_gets() and BIO_puts() are supported on file BIOs.
BIO_flush() on a file BIO calls the fflush() function on the wrapped
stream.
BIO_reset() on a file BIO calls fseek() to reset the position indicator
to the start of the file.
BIO_eof() calls feof().
Setting the BIO_CLOSE flag calls fclose() on the stream when the BIO
is freed.
BIO_new_file() creates a new file BIO with mode B<mode> the meaning
of B<mode> is the same as the stdio function fopen(). The BIO_CLOSE
flag is set on the returned BIO.
BIO_new_fp() creates a file BIO wrapping B<stream>. Flags can be:
BIO_CLOSE, BIO_NOCLOSE (the close flag) BIO_FP_TEXT (sets the underlying
stream to text mode, default is binary: this only has any effect under
Win32).
BIO_set_fp() set the fp of a file BIO to B<fp>. B<flags> has the same
meaning as in BIO_new_fp(), it is a macro.
BIO_get_fp() retrieves the fp of a file BIO, it is a macro.
BIO_read_filename(), BIO_write_filename(), BIO_append_filename() and
BIO_rw_filename() set the file BIO B<b> to use file B<name> for
reading, writing, append or read write respectively.
=head1 NOTES
When wrapping stdout, stdin or stderr the underlying stream should not
normally be closed so the BIO_NOCLOSE flag should be set.
Because the file BIO calls the underlying stdio functions any quirks
in stdio behaviour will be mirrored by the corresponding BIO.
=head1 EXAMPLES
File BIO "hello world":
BIO *bio_out;
bio_out = BIO_new_fp(stdout, BIO_NOCLOSE);
BIO_printf(bio_out, "Hello World\n");
Alternative technique:
BIO *bio_out;
bio_out = BIO_new(BIO_s_file());
if(bio_out == NULL) /* Error ... */
if(!BIO_set_fp(bio_out, stdout, BIO_NOCLOSE)) /* Error ... */
BIO_printf(bio_out, "Hello World\n");
Write to a file:
BIO *out;
out = BIO_new_file("filename.txt", "w");
if(!out) /* Error occurred */
BIO_printf(out, "Hello World\n");
BIO_free(out);
Alternative technique:
BIO *out;
out = BIO_new(BIO_s_file());
if(out == NULL) /* Error ... */
if(!BIO_read_filename(out, "filename.txt")) /* Error ... */
BIO_printf(out, "Hello World\n");
BIO_free(out);
=head1 RETURN VALUES
BIO_s_file() returns the file BIO method.
BIO_new_file() and BIO_new_fp() return a file BIO or NULL if an error
occurred.
BIO_set_fp() and BIO_get_fp() return 1 for success or 0 for failure
(although the current implementation never return 0).
BIO_read_filename(), BIO_write_filename(), BIO_append_filename() and
BIO_rw_filename() return 1 for success or 0 for failure.
=head1 SEE ALSO
L<BIO_seek(3)|BIO_seek(3)>, L<BIO_tell(3)|BIO_tell(3)>, TBA