[#BIO_read]
= BIO_read
:mrdocs:

Read up to `dlen` bytes from BIO `b` into `data.`

== Synopsis

Declared in `<openssl/bio.h>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
int
BIO_read(
    xref:BIO.adoc[BIO]* b,
    void* data,
    int dlen);
----

== Return Value

Number of bytes read, 0 on EOF/no data, or a negative value on error (see BIO_should_retry).

== Parameters

[cols="1,4"]
|===
| Name| Description
| *b*
| Source BIO.
| *data*
| Destination buffer.
| *dlen*
| Maximum number of bytes to read (must be non‐negative and fit in int).
|===


[.small]#Created with https://www.mrdocs.com[MrDocs]#