ACL_TO_TEXT(3) FreeBSD Library Functions Manual ACL_TO_TEXT(3)


acl_to_text, acl_to_text_npconvert an ACL to text


Standard C Library (libc, -lc)


#include < sys/types.h>
#include < sys/acl.h>

char *
acl_to_text( acl_t acl, ssize_t *len_p);

char *
acl_to_text_np( acl_t acl, ssize_t *len_p, int flags);


The acl_to_text() and acl_to_text_np() functions translate the ACL pointed to by argument acl into a NULL terminated character string. If the pointer len_p is not NULL, then the function shall return the length of the string (not including the NULL terminator) in the location pointed to by len_p. If the ACL is POSIX.1e, the format of the text string returned by acl_to_text() shall be the POSIX.1e long ACL form. If the ACL is NFSv4, the format of the text string shall be the compact form, unless the ACL_TEXT_VERBOSE flag is given.

The flags specified are formed by or'ing the following values

ACL_TEXT_VERBOSE Format ACL using verbose form
ACL_TEXT_NUMERIC_IDS Do not resolve IDs into user or group names
ACL_TEXT_APPEND_ID In addition to user and group names, append numeric IDs

This function allocates any memory necessary to contain the string and returns a pointer to the string. The caller should free any releasable memory, when the new string is no longer required, by calling acl_free(3) with the (void*)char as an argument.


FreeBSD's support for POSIX.1e interfaces and features is still under development at this time.


Upon successful completion, the function shall return a pointer to the long text form of an ACL. Otherwise, a value of (char*)NULL shall be returned and errno shall be set to indicate the error.


If any of the following conditions occur, the acl_to_text() function shall return a value of (acl_t)NULL and set errno to the corresponding value:
Argument acl does not point to a valid ACL.

The ACL denoted by acl contains one or more improperly formed ACL entries, or for some other reason cannot be translated into a text form of an ACL.

The character string to be returned requires more memory than is allowed by the hardware or software-imposed memory management constraints.


POSIX.1e is described in IEEE POSIX.1e draft 17. Discussion of the draft continues on the cross-platform POSIX.1e implementation mailing list. To join this list, see the FreeBSD POSIX.1e implementation page for more information.


POSIX.1e support was introduced in FreeBSD 4.0, and development continues.


Robert N M Watson


The acl_from_text() and acl_to_text() functions rely on the getpwent(3) library calls to manage username and uid mapping, as well as the getgrent(3) library calls to manage groupname and gid mapping. These calls are not thread safe, and so transitively, neither are acl_from_text() and acl_to_text(). These functions may also interfere with stateful calls associated with the getpwent() and getgrent() calls.
June 25, 2009 FreeBSD