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

# [NAME](#NAME)

io\_uring\_prep\_waitid - prepare a waitid request

# [SYNOPSIS](#SYNOPSIS)

```
#include <sys/wait.h>
#include <liburing.h>
```

```
void io_uring_prep_waitid(struct io_uring_sqe *sqe,
                          idtype_t idtype,
                          id_t id,
                          siginfo_t *infop,
                          int options,
                          unsigned int flags);
```

# [DESCRIPTION](#DESCRIPTION)

The [**io\_uring\_prep\_waitid**(3)](/man/os/liburing/io_uring_prep_waitid.3) function prepares a waitid request. The submission queue entry *sqe* is setup to use the *idtype* and *id* arguments select the child(ren), and *options* to specify the child state changes to wait for. Upon successful return, it fills *infop* with information of the child process, if any. *flags* is io\_uring specific modifier flags. They are currently unused, and hence **0** should be passed.

This function prepares an async [**waitid**(2)](/man/os/liburing/waitid.2) request. See that man page for details.

Available since kernel 6.7.

# [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), [**waitid**(2)](/man/os/liburing/waitid.2)

July 14, 2023 liburing-2.5

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Document: io_uring_prep_waitid(3) from liburing 2.15-r5 (Chainguard OS)
Source: https://github.com/axboe/liburing.git