---
name: "gnutls_record_send_file"
section: "3"
platform: "linux"
package: "gnutls"
version: "3.8.13-3"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/gnutls_record_send_file"
---

# gnutls\_record\_send\_file(3)

API function

## NAME

gnutls\_record\_send\_file - API function

## SYNOPSIS

**#include \<gnutls/gnutls.h\>**

**ssize\_t gnutls\_record\_send\_file(gnutls\_session\_t** *session***, int** *fd***, off\_t \*** *offset***, size\_t** *count***);**

## ARGUMENTS

- gnutls\_session\_t session

  is a **gnutls\_session\_t** type.

- int fd

  file descriptor from which to read data.

- off\_t \* offset

  Is relative to file offset, denotes the starting location for reading.  after function returns, it point to position following last read byte.

- size\_t count

  is the length of the data in bytes to be read from file and send.

## DESCRIPTION

This function sends data from  *fd* . If KTLS (kernel TLS) is enabled, it will use the **sendfile()** system call to avoid overhead of copying data between user space and the kernel. Otherwise, this functionality is merely emulated by calling **read()** and **gnutls\_record\_send()**. If this implementation is suboptimal, check whether KTLS is enabled using **gnutls\_transport\_is\_ktls\_enabled()**.

If  *offset* is NULL then file offset is incremented by number of bytes send, otherwise file offset remains unchanged.

## RETURNS

The number of bytes sent, or a negative error code.

## REPORTING BUGS

Report bugs to \<bugs@gnutls.org\>.\
 Home page: https://www.gnutls.org

## COPYRIGHT

Copyright © 2001-2023 Free Software Foundation, Inc., and others.\
 Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved.

## SEE ALSO

The full documentation for **gnutls** is maintained as a Texinfo manual. If the /usr/share/doc/gnutls/ directory does not contain the HTML form visit

- https://www.gnutls.org/manual/