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17 .\" @(#)getattrlistbulk.2
24 .Nd get file system attributes for multiple directory entries
26 .Fd #include <sys/attr.h>
27 .Fd #include <unistd.h>
30 .Fn getattrlistbulk "int dirfd" "struct attrlist * attrList" "void * attrBuf" "size_t attrBufSize" "uint64_t options"
36 function iterates over the items in a directory and returns information about
37 each directory entry like
41 returns information about a symbolic link, the information returned is about the link itself, not the target of the link.
42 The order of the directory entries (and their associated metadata) vended by
44 is not specified. Some file systems may return entries in lexicographic sort order and others may not.
46 The function reads directory entries from the directory referenced by the file
51 parameter determines what attributes are returned for each entry.
52 Attributes of those directory entries are placed into the buffer specified by
58 parameter allows you to modify the behaviour of the call.
67 parameter must be a file descriptor that references a directory that you have opened for reading.
70 .\" attrList parameter
74 parameter is a pointer to an
77 All fields of this structure must be filled before calling the function.
78 See the discussion of the
80 function for a detailed description of this structure.
81 To get an attribute, the corresponding bit in the appropriate
85 structure must be set.
86 Volume attributes cannot be requested but all other supported getattrlist attributes can be used. For this function,
89 .Dv ATTR_CMN_RETURNED_ATTRS
90 are required and the absence of these attributes in the attrList parameter results in an error. Note that
91 not all attributes supported by
93 may be vended back by this call, which is why the aforementioned flag must be supplied. In particular
95 may not be valid on all directory entries whose information is requested by this call.
98 .\" attrBuf and attrBufSize parameters
104 parameters specify a buffer into which the function places attribute values.
105 The attributes for any given directory entry are grouped together and
106 packed in exactly the same way as they are returned from
108 and are subject to exactly the same alignment specifications
109 and restrictions. These groups are then placed into the buffer, one after another.
110 .Xr getattrlist 2 should be consulted on details of the attributes that can be
111 requested for and returned. The name of the entry itself is provided by the
113 attribute. Each group starts with a leading
115 , which will always be 8-byte aligned that contains the overall length of the group.
116 You can step from one group to the next by simply adding this length to your pointer.
117 The sample code (below) shows how to do this.
118 The initial contents of this buffer are ignored.
121 .\" options parameter
125 parameter is a bit set that controls the behaviour of
126 .Fn getattrlistbulk .
127 The following option bits are defined.
129 .Bl -tag -width FSOPT_PACK_INVAL_ATTRS
131 .It FSOPT_PACK_INVAL_ATTRS
132 If this is bit is set, then all requested attributes,
133 even ones that are not supported by the object or file
134 file system, will be returned the attrBuf. The attributes
135 actually returned can be determined by looking at the
136 attribute_set_t structure returned for the
137 .Dv ATTR_CMN_RETURNED_ATTRS
138 attribute. Default values will be returned for invalid
139 attributes and should be ignored.
141 Please see the discussion of this flag in
148 has been requested and an error specific to a directory entry occurs,
149 an error will be reported. The
151 attribute is a uint32_t which, if non-zero, specifies the error code
152 that was encountered during the processing of that directory entry. The
154 attribute will be after
155 .Dv ATTR_CMN_RETURNED_ATTRS
156 attribute in the returned buffer.
158 It is typical to ask for a combination of common, file, and directory
159 attributes and then use the value of the
161 attribute to parse the resulting attribute buffer.
163 A directory which is a mount point for a file system, will have a value of
164 .Dq DIR_MNTSTATUS_MNTPOINT
165 set for its ATTR_DIR_MOUNTSTATUS attribute entry.
166 However the attributes for the mount point will be those from the (underlying) file system.
167 To get the attributes of the mounted root directory, call
171 A directory which is a firmlink will have the
173 flag set in its ATTR_CMN_FLAGS attribute entry.
174 However, the attributes returned by
176 will be those from the firmlink, not the firmlink's target.
177 To get the attribute of the firmlink's target, call
182 Upon successful completion the numbers of entries successfully read
183 is returned. A value of 0 indicates there are no more entries. Once 0 is returned,
184 no further entries are returned even if new entries are added to the directory.
185 Directory iteration should be restarted either by repostioning the offset to 0 by
187 or by closing the file descriptor and opening the directory again. On error,
188 a value of -1 is returned and
190 is set to indicate the error.
192 When iterating all entries in a directory,
194 is called repeatedly until a 0 is returned. In such a case if
198 calls on the same fd are mixed, the behavior is undefined.
208 is not a valid file descriptor for a directory open for reading.
216 Search permission is denied on the directory whose descriptor is given
223 points to an invalid address.
226 The buffer was too small.
234 .Dv ATTR_BIT_MAP_COUNT .
237 An invalid attribute was requested.
240 Volume attributes were requested.
245 .Dv ATTR_CMN_RETURNED_ATTRS
246 was not requested in the attrList parameter.
249 An I/O error occurred while reading from or writing to the file system.
255 The following code lists the contents of a directory using
256 .Fn getattrlistbulk .
257 The listing includes the file type.
260 #include <sys/syscall.h>
261 #include <sys/attr.h>
262 #include <sys/errno.h>
263 #include <sys/vnode.h>
272 typedef struct val_attrs {
274 attribute_set_t returned;
276 attrreference_t name_info;
278 fsobj_type_t obj_type;
282 void demo(const char *dirpath)
286 struct attrlist attrList;
290 memset(&attrList, 0, sizeof(attrList));
291 attrList.bitmapcount = ATTR_BIT_MAP_COUNT;
292 attrList.commonattr = ATTR_CMN_RETURNED_ATTRS |
298 dirfd = open(dirpath, O_RDONLY, 0);
301 printf("Could not open directory %s", dirpath);
302 perror("Error was ");
307 retcount = getattrlistbulk(dirfd, &attrList, &attrBuf[0],
309 printf("\engetattrlistbulk returned %d", retcount);
310 if (retcount == -1) {
312 perror("Error returned : ");
315 } else if (retcount == 0) {
316 /* No more entries in directory */
321 uint32_t total_length;
324 entry_start = &attrBuf[0];
326 printf(" -> entries returned");
327 for (index = 0; index < retcount; index++) {
328 val_attrs_t attrs = {0};
330 printf("\en Entry %d", index);
333 attrs.length = *(uint32_t *)field;
334 printf(" Length %d ", attrs.length);
335 total_length += attrs.length;
336 printf(" Total Length %d ", total_length);
337 field += sizeof(uint32_t);
340 /* set starting point for next entry */
341 entry_start += attrs.length;
343 attrs.returned = *(attribute_set_t *)field;
344 field += sizeof(attribute_set_t);
346 if (attrs.returned.commonattr & ATTR_CMN_ERROR) {
347 attrs.error = *(uint32_t *)field;
348 field += sizeof(uint32_t);
351 if (attrs.returned.commonattr & ATTR_CMN_NAME) {
353 attrs.name_info = *(attrreference_t *)field;
354 field += sizeof(attrreference_t);
355 printf(" %s ", (attrs.name +
356 attrs.name_info.attr_dataoffset));
359 /* Check for error for this entry */
362 * Print error and move on to next
365 printf("Error in reading attributes for directory \
366 entry %d", attrs.error);
371 if (attrs.returned.commonattr & ATTR_CMN_OBJTYPE) {
372 attrs.obj_type = *(fsobj_type_t *)field;
373 field += sizeof(fsobj_type_t);
375 switch (attrs.obj_type) {
380 printf("directory ");
383 printf("obj_type = %-2d ", attrs.obj_type);
405 function call appeared in OS X version 10.10