---
name: "radcli_avp_add_bytes"
section: "3"
platform: "linux"
package: "radcli"
version: "2.0.1-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/radcli_avp_add_bytes"
---

# radcli\_avp\_add\_bytes(3)

Append an attribute holding an arbitrary byte string.

## NAME

radcli\_avp\_add\_bytes - Append an attribute holding an arbitrary byte string.

## SYNOPSIS

```
#include <radcli/>

int radcli_avp_add_bytes(
    radcli_avp_list        *list,
    const radcli_attr_def  *def,
    const void             *value,
    size_t                  len
);
```

## DESCRIPTION

The primitive every other radcli\_avp\_add\_\*() function is defined in terms of; valid for any attribute type, since the underlying representation is always length-carrying bytes.

## PARAMETERS

- **list**

  destination list.

- **def**

  the attribute, from radcli\_dict\_lookup() or a sibling.

- **value**

  the bytes to copy in; may be NULL only if len is 0.

- **len**

  number of bytes at value.

## RETURN VALUE

0 on success, -1 on failure (allocation failure, or NULL list/def).

## SEE ALSO

[*radcli\_avp\_add\_bytes\_by\_num*(3)](/radcli_avp_add_bytes_by_num/3.md), [*radcli\_avp\_add\_gigawords64*(3)](/radcli_avp_add_gigawords64/3.md), [*radcli\_avp\_add\_gigawords64\_by\_num*(3)](/radcli_avp_add_gigawords64_by_num/3.md), [*radcli\_avp\_add\_ip4*(3)](/radcli_avp_add_ip4/3.md), [*radcli\_avp\_add\_ip4\_by\_num*(3)](/radcli_avp_add_ip4_by_num/3.md), [*radcli\_avp\_add\_ip4prefix*(3)](/radcli_avp_add_ip4prefix/3.md), [*radcli\_avp\_add\_ip4prefix\_by\_num*(3)](/radcli_avp_add_ip4prefix_by_num/3.md), [*radcli\_avp\_add\_ip6*(3)](/radcli_avp_add_ip6/3.md), [*radcli\_avp\_add\_ip6\_by\_num*(3)](/radcli_avp_add_ip6_by_num/3.md), [*radcli\_avp\_add\_str*(3)](/radcli_avp_add_str/3.md), [*radcli\_avp\_add\_str\_by\_num*(3)](/radcli_avp_add_str_by_num/3.md), [*radcli\_avp\_add\_uint32*(3)](/radcli_avp_add_uint32/3.md), [*radcli\_avp\_add\_uint32\_by\_num*(3)](/radcli_avp_add_uint32_by_num/3.md), [*radcli\_avp\_add\_uint64*(3)](/radcli_avp_add_uint64/3.md), [*radcli\_avp\_add\_uint64\_by\_num*(3)](/radcli_avp_add_uint64_by_num/3.md), [*radcli\_avp\_add\_username*(3)](/radcli_avp_add_username/3.md), [*radcli\_avp\_concat\_str*(3)](/radcli_avp_concat_str/3.md), [*radcli\_avp\_concat\_str\_by\_num*(3)](/radcli_avp_concat_str_by_num/3.md), [*radcli\_avp\_def*(3)](/radcli_avp_def/3.md), [*radcli\_avp\_get*(3)](/radcli_avp_get/3.md), [*radcli\_avp\_get\_by\_num*(3)](/radcli_avp_get_by_num/3.md), [*radcli\_avp\_get\_bytes*(3)](/radcli_avp_get_bytes/3.md), [*radcli\_avp\_get\_bytes\_by\_num*(3)](/radcli_avp_get_bytes_by_num/3.md), [*radcli\_avp\_get\_cstr*(3)](/radcli_avp_get_cstr/3.md), [*radcli\_avp\_get\_cstr\_by\_num*(3)](/radcli_avp_get_cstr_by_num/3.md), [*radcli\_avp\_get\_gigawords64*(3)](/radcli_avp_get_gigawords64/3.md), [*radcli\_avp\_get\_gigawords64\_by\_num*(3)](/radcli_avp_get_gigawords64_by_num/3.md), [*radcli\_avp\_get\_ip4prefix*(3)](/radcli_avp_get_ip4prefix/3.md), [*radcli\_avp\_get\_ip4prefix\_by\_num*(3)](/radcli_avp_get_ip4prefix_by_num/3.md), [*radcli\_avp\_get\_ip6*(3)](/radcli_avp_get_ip6/3.md), [*radcli\_avp\_get\_ip6\_by\_num*(3)](/radcli_avp_get_ip6_by_num/3.md), [*radcli\_avp\_get\_uint32*(3)](/radcli_avp_get_uint32/3.md), [*radcli\_avp\_get\_uint32\_by\_num*(3)](/radcli_avp_get_uint32_by_num/3.md), [*radcli\_avp\_get\_uint64*(3)](/radcli_avp_get_uint64/3.md), [*radcli\_avp\_get\_uint64\_by\_num*(3)](/radcli_avp_get_uint64_by_num/3.md), [*radcli\_avp\_iter\_next*(3)](/radcli_avp_iter_next/3.md), [*radcli\_avp\_list\_error*(3)](/radcli_avp_list_error/3.md), [*radcli\_avp\_list\_free*(3)](/radcli_avp_list_free/3.md), [*radcli\_avp\_list\_iter*(3)](/radcli_avp_list_iter/3.md), [*radcli\_avp\_list\_new*(3)](/radcli_avp_list_new/3.md)