STAT_FLAGS(3) Library Functions Manual STAT_FLAGS(3)

string_to_flags, flags_to_string
Stat flags parsing and printing functions

System Utilities Library (libutil, -lutil)

#include <util.h>

char *
flags_to_string(u_long flags, const char *def);

int
string_to_flags(char **stringp, u_long *setp, u_long *clrp);

The flags_to_string() and string_to_flags() functions are used by programs such as chflags(1), ls(1), makefs(8), mtree(8), etc., to parse and/or print the st_flags field in the stat(2) structure.

They recognize the following flags:

, archived (SF_ARCHIVED)
file is archived (legacy/compat flag for mount_msdos(8) filesystems)
(UF_NODUMP)
do not dump(8) file
(UF_OPAQUE)
directory is opaque in mount_union(8) filesystems
, sappend (SF_APPEND)
writes to the file may only append (flag can be changed by the superuser only)
, schange, simmutable (SF_IMMUTABLE)
file cannot be changed; it is immutable (flag can be changed by the superuser only)
(SF_SNAPSHOT)
file is an fss(4) snapshot inode
, uappend (UF_APPEND)
writes to the file may only append
, uchange, uimmutable (UF_IMMUTABLE)
file cannot be changed; it is immutable

The flags_to_string() function converts the bits set in the flags argument to a comma-separated string and returns it. If no flags are set, then the def string is returned. The returned string is allocated via malloc(3) and it is the responsibility of the caller to free(3) it.

Where the above list has several flag names for a flag, the first of the listed names is returned.

The string_to_flags() function takes a stringp of space, comma, or tab separated flag names and places their bit value on the setp argument.

If the flag name is prefixed by ‘no’, then the bit value is placed on the clrp argument. Both nonodump and dump are recognized as negative forms of the nodump flag name.

Where the above list has several flag names for a flag, all of them are recognized. The snap flag name is not recognized (as its flag cannot be changed anyway).

flags_to_string() returns the symbolic representation of flags, the default string, or NULL if allocation failed.

string_to_flags() returns 0 on success and 1 if it fails to parse the string, setting stringp to point to the first name that it failed to parse.

chflags(2), stat(2)
May 31, 2023 NetBSD 10.1