diff options
author | Dr. Stephen Henson <steve@openssl.org> | 2000-09-13 17:27:42 +0000 |
---|---|---|
committer | Dr. Stephen Henson <steve@openssl.org> | 2000-09-13 17:27:42 +0000 |
commit | 02ef611ef337943e46a03239e87825b4b202cfa7 (patch) | |
tree | a59ad9756d125690d972cd1b7a759fef0938f91b /doc | |
parent | 24b8bf2163e6a2985313eefc4557316ee39e43c6 (diff) |
BIO_s_fd() manual page.
Diffstat (limited to 'doc')
-rw-r--r-- | doc/crypto/BIO_s_fd.pod | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/doc/crypto/BIO_s_fd.pod b/doc/crypto/BIO_s_fd.pod new file mode 100644 index 0000000000..5c7c55fa89 --- /dev/null +++ b/doc/crypto/BIO_s_fd.pod @@ -0,0 +1,88 @@ +=pod + +=head1 NAME + + BIO_s_fd - file descriptor BIO + +=head1 SYNOPSIS + + #include <openssl/bio.h> + + BIO_METHOD * BIO_s_fd(void); + + #define BIO_seek(b,ofs) (int)BIO_ctrl(b,BIO_C_FILE_SEEK,ofs,NULL) + #define BIO_tell(b) (int)BIO_ctrl(b,BIO_C_FILE_TELL,0,NULL) + + #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); + +=head1 DESCRIPTION + +BIO_f_fd() returns the file descriptor BIO method. This is a wrapper +round the platforms file descriptor routines such as read() and write(). + +BIO_read() and BIO_write() 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. + +BIO_reset() attempts to change the file pointer to the start of file +using lseek(fd, 0, 0). + +BIO_seek() sets the file pointer to position B<ofs> from start of file +using lseek(fd, ofs, 0). + +BIO_tell() returns the current file position by calling lseek(fd, 0, 1). + +BIO_set_fd() sets the file descriptor of BIO B<b> to B<fd> and the close +flag to B<c>. + +BIO_get_fd() places the file descriptor in B<c> if it is not NULL, it also +returns the file descriptor. If B<c> is not NULL it should be of type +(int *). + +BIO_new_fd() returns a file desciptor BIO using B<fd> and B<close_flag>. + +=head1 NOTES + +The behaviour of BIO_read() and BIO_write() depends on the behaviour of the +platforms read() and write() calls on the descriptor. If the underlying +file descriptor is in a non blocking mode then the BIO will behave in the +manner described in the L<BIO_read(3)|BIO_read(3)> and L<BIO_should_retry(3)|BIO_should_retry(3)> +manual pages. + +File descriptor BIOs should not be used for socket I/O. Use socket BIOs +instead. + +=head1 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() +behaviour. + +BIO_set_fd() always returns 1. + +BIO_get_fd() returns the file descriptor or -1 if the BIO has not +been initialised. + +BIO_new_fd() returns the newly allocated BIO or NULL is an error +occurred. + +=head1 EXAMPLE + +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); + +=head1 SEE ALSO + +TBA |