io\_uring\_prep\_ftruncate(3) liburing Manual io\_uring\_prep\_ftruncate(3)

# [NAME](#NAME)

io\_uring\_prep\_ftruncate - prepare an ftruncate request

# [SYNOPSIS](#SYNOPSIS)

```
#include <liburing.h>
```

```
void io_uring_prep_ftruncate(struct io_uring_sqe *sqe,
                             int fd,
                             loff_t len);
```

# [DESCRIPTION](#DESCRIPTION)

The [**io\_uring\_prep\_ftruncate**(3)](/man/os/liburing/io_uring_prep_ftruncate.3) function prepares an ftruncate request. The submission queue entry *sqe* is setup to use the file descriptor *fd* that should get truncated to the length indicated by the *len* argument.

Applications must define **\_GNU\_SOURCE** to obtain the definition of this helper, as *loff\_t* will not be defined without it.

# [RETURN VALUE](#RETURN_VALUE)

None

# [ERRORS](#ERRORS)

The CQE *res* field will contain the result of the operation. See the related man page for details on possible values. Note that where synchronous system calls will return **-1** on failure and set *errno* to the actual error value, io\_uring never uses *errno*. Instead it returns the negated *errno* directly in the CQE *res* field.

# [SEE ALSO](#SEE_ALSO)

[**io\_uring\_get\_sqe**(3)](/man/os/liburing/io_uring_get_sqe.3), [**io\_uring\_submit**(3)](/man/os/liburing/io_uring_submit.3), [**ftruncate**(2)](/man/os/liburing/ftruncate.2),

January 23, 2024 liburing-2.6

---

Document: io_uring_prep_ftruncate(3) from liburing 2.15-r4 (Chainguard OS)
Source: https://github.com/axboe/liburing.git