REMOVEFILE(3) BSD Library Functions Manual REMOVEFILE(3)NAME
removefile, removefile_state_alloc, removefile_state_free,
removefile_state_get, removefile_state_set — remove files or directories
SYNOPSIS
#include <removefile.h>
int
removefile(const char *path, removefile_state_t state,
removefile_flags_t flags);
removefile_state_t
removefile_state_alloc(void);
int
removefile_state_free(removefile_state_t state);
int
removefile_state_get(removefile_state_t state, uint32_t key, void * dst);
int
removefile_state_set(removefile_state_t state, uint32_t key,
const void * value);
int
removefile_cancel(removefile_state_t state);
DESCRIPTION
These functions are used to remove a file or directory. Various levels
of overwriting may be specified to prevent other people from recovering
any information about the file.
The removefile_state_alloc() function initializes a removefile_state_t
object (which is an opaque data type). This object can be passed to
removefile(). removefile_state_get() and removefile_state_set() can be
used to manipulate the state (see below). The removefile_state_free()
function is used to deallocate the object and its contents.
The removefile() function removes files and directories located at the
named path filesystem location. The named path location can be specified
as either an absolute path or relative to the working directory of the
calling process. If the state parameter is the return value from
removefile_state_alloc(), then removefile() will use the information from
the state object; if it is NULL, then removefile() will work normally,
but less control will be available to the caller. The flags parameter
controls deletion options:
REMOVEFILE_RECURSIVE If the path location is a directory, then
recursively delete the entire directory.
REMOVEFILE_KEEP_PARENT The file or directory at the path location
is not deleted. If specified in conjunc‐
tion with REMOVEFILE_RECURSIVE, then all
of the contents of the directory at path
location will be deleted, but not the
directory itself.
REMOVEFILE_SECURE_7_PASS Overwrite the file with 7 US DoD compliant
passes (0xF6, 0x00, 0xFF, random, 0x00,
0xFF, random).
REMOVEFILE_SECURE_35_PASS Overwrite the file using 35-pass Gutmann
algorithm.
REMOVEFILE_SECURE_3_PASS Overwrite the file twice with random
bytes, and then with 0xAA.
REMOVEFILE_SECURE_1_PASS Overwrite with a single pass of random
data.
REMOVEFILE_SECURE_1_PASS_ZERO Overwrite with a single pass of zeroes.
The removefile_state_get() and removefile_state_set() functions can be
used to manipulate the removefile_state_t object returned by
removefile_state_alloc(). In both functions, the dst or the value param‐
eter's type depends on the key parameter that is passed in.
REMOVEFILE_STATE_CONFIRM_CALLBACK Get or set the callback function of
type removefile_callback_t to be
called prior to file deletion.
REMOVEFILE_STATE_CONFIRM_CONTEXT Get or set any parameters of type void
* that are needed for the confirm
callback function.
REMOVEFILE_STATE_ERROR_CALLBACK Get or set the callback function of
type removefile_callback_t to be
called when an error is detected.
REMOVEFILE_STATE_ERROR_CONTEXT Get or set any parameters of type void
* that are needed for the error call‐
back function.
REMOVEFILE_STATE_ERRNO Get or set the current errno of type
int
REMOVEFILE_STATE_STATUS_CALLBACK Get or set the callback function of
type removefile_callback_t to be
called subsequent to file deletion.
REMOVEFILE_STATE_STATUS_CONTEXT Get or set any parameters of type void
* that are needed for the status call‐
back function.
The removefile_callback_t function pointer is defined as the following:
int (*removefile_callback_t) (removefile_state_t state, const char *path,
void *context)
The return value of the callback function is given as:
REMOVEFILE_PROCEED File is deleted and removefile() continues operation
as normal.
REMOVEFILE_SKIP Current file is not deleted and removefile() contin‐
ues operation as normal.
REMOVEFILE_STOP Current file is not deleted and removefile() exits
without continuing further.
The removefile_cancel() function is used to cancel a remove that is in
progress.
RETURN VALUES
The family of removefile() functions returns less than 0 on error, and 0
on success.
ERRORSremovefile() will fail if:
[EACCES] The path location specifies a file or directory for
which the calling process does not have proper permis‐
sions.
[EINVAL] A callback returned an invalid return value (not
REMOVEFILE_PROCEED, REMOVEFILE_SKIP, or REMOVE‐
FILE_STOP)
[EMLINK] The path location refers to a symbolic link.
[ENAMETOOLONG] The resource fork name of the file exceeds the maximum
allowed length.
[ENOMEM] A memory allocation failed.
[ENOTEMPTY] The path location specifies a directory that contains
an immutable file which cannot be deleted.
[EPERM] The path location specifies an immutable file that
cannot be deleted.
removefile_cancel() will fail if:
[EINVAL] A NULL parameter was passed into removefile_cancel().
In addition, all functions may return an error from an underlying library
or system call.
NOTES
Write protected files owned by another user cannot be removed by
removefile(), regardless of the permissions on the directory containing
the file.
If multiple of the REMOVEFILE_SECURE_1_PASS, REMOVEFILE_SECURE_7_PASS,
and REMOVEFILE_SECURE_35_PASS flags are specified, removefile() will pro‐
ceed using the flag that specifies the highest number of overwriting
passes.
removefile() is pathname-based; this means that, when descending into a
hierarchy, there are potential race conditions that may add risk when run
with privileges.
removefile() operates on symbolic links, rather than the target of the
link.
EXAMPLES
/* Initialize a state variable */
removefile_state_t s;
s = removefile_state_alloc();
/* Recursively remove all files and directories while keeping parent tmp directory. */
removefile("/tmp", s, REMOVEFILE_RECURSIVE | REMOVEFILE_KEEP_PARENT);
/* Release the state variable */
removefile_state_free(s);
/* A more complex way to call removefile()-- define a callback function */
int removefile_status_callback(removefile_state_t state, const char * path, void * context) {
fprintf(stderr, "File deleted: %s", path);
return REMOVEFILE_PROCEED;
}
/* Initialize a state variable */
s = removefile_state_alloc();
/* Set callback function properties */
removefile_state_set(s, REMOVEFILE_STATE_CONFIRM_CALLBACK, removefile_confirm_callback);
removefile_state_set(s, REMOVEFILE_STATE_CONFIRM_CONTEXT, NULL);
/* Recursively remove all files and directories while keeping parent tmp directory,
calling a confirm callback prior to each file deletion. */
removefile("/tmp", s, REMOVEFILE_RECURSIVE | REMOVEFILE_KEEP_PARENT);
/* Release the state variable. */
removefile_state_free(s);
SEE ALSOsrm(1), unlink(1), sync(2), sync_volume_np(3)HISTORY
The removefile() API was introduced in Mac OS X 10.5.
BSD May 4, 2007 BSD
