---
name: "ck_ht_entry_key"
section: "3"
platform: "linux"
package: "libck-dev"
version: "0.7.2-6"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/ck_ht_entry_key"
---

# ck\_ht\_entry\_key(3)

return pointer to key as specified in hash table entry

## NAME

**ck\_ht\_entry\_key** – return pointer to key as specified in hash table entry

## LIBRARY

Concurrency Kit (libck, -lck)

## SYNOPSIS

**#include \<ck\_ht.h\>**

*void* *\**\

**ck\_ht\_entry\_key**(*ck\_ht\_entry\_t \*entry*);

## DESCRIPTION

The **ck\_ht\_entry\_key**() function will return the key pointer as specified in the object pointed to by the *entry* argument.

It is expected that the entry is associated with a hash table initialized with CK\_HT\_MODE\_BYTESTRING (see [ck\_ht\_init(3)](/ck_ht_init/3.md) for more information).

## RETURN VALUES

**ck\_ht\_entry\_key**() returns NULL if the entry is empty.

## ERRORS

Behavior is undefined if *entry* has not been initialized.

## SEE ALSO

[ck\_ht\_stat(3)](/ck_ht_stat/3.md), [ck\_ht\_init(3)](/ck_ht_init/3.md), [ck\_ht\_destroy(3)](/ck_ht_destroy/3.md), [ck\_ht\_hash(3)](/ck_ht_hash/3.md), [ck\_ht\_hash\_direct(3)](/ck_ht_hash_direct/3.md), [ck\_ht\_set\_spmc(3)](/ck_ht_set_spmc/3.md), [ck\_ht\_put\_spmc(3)](/ck_ht_put_spmc/3.md), [ck\_ht\_gc(3)](/ck_ht_gc/3.md), [ck\_ht\_get\_spmc(3)](/ck_ht_get_spmc/3.md), [ck\_ht\_grow\_spmc(3)](/ck_ht_grow_spmc/3.md), [ck\_ht\_remove\_spmc(3)](/ck_ht_remove_spmc/3.md), [ck\_ht\_count(3)](/ck_ht_count/3.md), [ck\_ht\_reset\_spmc(3)](/ck_ht_reset_spmc/3.md), [ck\_ht\_reset\_size\_spmc(3)](/ck_ht_reset_size_spmc/3.md), [ck\_ht\_entry\_empty(3)](/ck_ht_entry_empty/3.md), [ck\_ht\_entry\_key\_set(3)](/ck_ht_entry_key_set/3.md), [ck\_ht\_entry\_key\_set\_direct(3)](/ck_ht_entry_key_set_direct/3.md), [ck\_ht\_entry\_key\_length(3)](/ck_ht_entry_key_length/3.md), [ck\_ht\_entry\_value(3)](/ck_ht_entry_value/3.md), [ck\_ht\_entry\_set(3)](/ck_ht_entry_set/3.md), [ck\_ht\_entry\_set\_direct(3)](/ck_ht_entry_set_direct/3.md), [ck\_ht\_entry\_key\_direct(3)](/ck_ht_entry_key_direct/3.md), [ck\_ht\_entry\_value\_direct(3)](/ck_ht_entry_value_direct/3.md), [ck\_ht\_iterator\_init(3)](/ck_ht_iterator_init/3.md), [ck\_ht\_next(3)](/ck_ht_next/3.md)

Additional information available at http://concurrencykit.org/