diff options
Diffstat (limited to 'doc/crypto/BIO_ctrl.pod')
| -rw-r--r-- | doc/crypto/BIO_ctrl.pod | 28 |
1 files changed, 8 insertions, 20 deletions
diff --git a/doc/crypto/BIO_ctrl.pod b/doc/crypto/BIO_ctrl.pod index 722e8b8f46..acc46db8ce 100644 --- a/doc/crypto/BIO_ctrl.pod +++ b/doc/crypto/BIO_ctrl.pod @@ -47,8 +47,8 @@ BIO_reset() typically resets a BIO to some initial state, in the case of file related BIOs for example it rewinds the file pointer to the start of the file. -BIO_seek() resets a file related BIO's (that is file descriptor and -FILE BIOs) file position pointer to B<ofs> bytes from start of file. +BIO_seek() resets a file related BIO's file position pointer to B<ofs> +bytes from start of file. BIO_tell() returns the current file position of a file related BIO. @@ -73,12 +73,10 @@ macros which call BIO_ctrl(). =head1 RETURN VALUES -BIO_reset() normally returns 1 for success and 0 or -1 for failure. File -BIOs are an exception, they return 0 for success and -1 for failure. +BIO_reset() returns 1 for success and 0 for failure. BIO_seek() and BIO_tell() both return the current file position on success -and -1 for failure, except file BIOs which for BIO_seek() always return 0 -for success and -1 for failure. +and -1 for failure. BIO_flush() returns 1 for success and 0 or -1 for failure. @@ -104,24 +102,14 @@ case of a file BIO some data may be available in the FILE structures internal buffers but it is not possible to determine this in a portably way. For other types of BIO they may not be supported. -Filter BIOs if they do not internally handle a particular BIO_ctrl() +Filter BIOs if the do not internally handle a particular BIO_ctrl() operation usually pass the operation to the next BIO in the chain. This often means there is no need to locate the required BIO for a particular operation, it can be called on a chain and it will -be automatically passed to the relevant BIO. However this can cause -unexpected results: for example no current filter BIOs implement -BIO_seek(), but this may still succeed if the chain ends in a FILE -or file descriptor BIO. +be automatically passed to the relevant BIO. -Source/sink BIOs return an 0 if they do not recognize the BIO_ctrl() -operation. - -=head1 BUGS - -Some of the return values are ambiguous and care should be taken. In -particular a return value of 0 can be returned if an operation is not -supported, if an error occurred, if EOF has not been reached and in -the case of BIO_seek() on a file BIO for a successful operation. +Source/sink BIOs will return an error if the do not recognize the +BIO_ctrl() operation. =head1 SEE ALSO |