.\" .\" Copyright (c) 2002 Apple Computer, Inc. All rights reserved. .\" .Dd April 27, 2006 .Dt COPYFILE 3 .Os .Sh NAME .Nm copyfile , fcopyfile , .Nm copyfile_state_alloc , copyfile_state_free , .Nm copyfile_state_get , copyfile_state_set .Nd copy a file .Sh LIBRARY .Lb libc .Sh SYNOPSIS .In copyfile.h .Ft int .Fn copyfile "const char *from" "const char *to" "copyfile_state_t state" "copyfile_flags_t flags" .Ft int .Fn fcopyfile "int from" "int to" "copyfile_state_t state" "copyfile_flags_t flags" .Ft copyfile_state_t .Fn copyfile_state_alloc "void" .Ft int .Fn copyfile_state_free "copyfile_state_t state" .Ft int .Fn copyfile_state_get "copyfile_state_t state" "uint32_t flag" "void * dst" .Ft int .Fn copyfile_state_set "copyfile_state_t state" "uint32_t flag" "const void * src" .Ft typedef int .Fn (*copyfile_callback_t) "int what" "int stage" "copyfile_state_t state" "const char * src" "const char * dst" "void * ctx" .Sh DESCRIPTION These functions are used to copy a file's data and/or metadata. (Metadata consists of permissions, extended attributes, access control lists, and so forth.) .Pp The .Fn copyfile_state_alloc function initializes a .Vt copyfile_state_t object (which is an opaque data type). This object can be passed to .Fn copyfile and .Fn fcopyfile ; .Fn copyfile_state_get and .Fn copyfile_state_set can be used to manipulate the state (see below). The .Fn copyfile_state_free function is used to deallocate the object and its contents. .Pp The .Fn copyfile function can copy the named .Va from file to the named .Va to file; the .Fn fcopyfile function does the same, but using the file descriptors of already-opened files. If the .Va state parameter is the return value from .Fn copyfile_state_alloc , then .Fn copyfile and .Fn fcopyfile will use the information from the state object; if it is .Dv NULL , then both functions will work normally, but less control will be available to the caller. The .Va flags parameter controls which contents are copied: .Bl -tag -width COPYFILE_XATTR .It Dv COPYFILE_ACL Copy the source file's access control lists. .It Dv COPYFILE_STAT Copy the source file's POSIX information (mode, modification time, etc.). .It Dv COPYFILE_XATTR Copy the source file's extended attributes. .It Dv COPYFILE_DATA Copy the source file's data. .El .Pp These values may be or'd together; several convenience macros are provided: .Bl -tag -width COPYFILE_SECURITY .It Dv COPYFILE_SECURITY Copy the source file's POSIX and ACL information; equivalent to .Dv (COPYFILE_STAT|COPYFILE_ACL) . .It Dv COPYFILE_METADATA Copy the metadata; equivalent to .Dv (COPYFILE_SECURITY|COPYFILE_XATTR) . .It Dv COPYFILE_ALL Copy the entire file; equivalent to .Dv (COPYFILE_METADATA|COPYFILE_DATA) . .El .Pp The .Fn copyfile and .Fn fcopyfile functions can also have their behavior modified by the following flags: .Bl -tag -width COPYFILE_NOFOLLOW_SRC .It Dv COPYFILE_RECURSIVE Causes .Fn copyfile to recursively copy a hierarchy. This flag is not used by .Fn fcopyfile ; see below for more information. .It Dv COPYFILE_CHECK Return a bitmask (corresponding to the .Va flags argument) indicating which contents would be copied; no data are actually copied. (E.g., if .Va flags was set to .Dv COPYFILE_CHECK|COPYFILE_METADATA , and the .Va from file had extended attributes but no ACLs, the return value would be .Dv COPYFILE_XATTR .) .It Dv COPYFILE_PACK Serialize the .Va from file. The .Va to file is an AppleDouble-format file. .It Dv COPYFILE_UNPACK Unserialize the .Va from file. The .Va from file is an AppleDouble-format file; the .Va to file will have the extended attributes, ACLs, resource fork, and FinderInfo data from the .Va to file, regardless of the .Va flags argument passed in. .It Dv COPYFILE_EXCL Fail if the .Va to file already exists. (This is only applicable for the .Fn copyfile function.) .It Dv COPYFILE_NOFOLLOW_SRC Do not follow the .Va from file, if it is a symbolic link. (This is only applicable for the .Fn copyfile function.) .It Dv COPYFILE_NOFOLLOW_DST Do not follow the .Va to file, if it is a symbolic link. (This is only applicable for the .Fn copyfile function.) .It Dv COPYFILE_MOVE Unlink (using .Xr remove 3 ) the .Fa from file. (This is only applicable for the .Fn copyfile function.) No error is returned if .Xr remove 3 fails. Note that .Xr remove 3 removes a symbolic link itself, not the target of the link. .It Dv COPYFILE_UNLINK Unlink the .Va to file before starting. (This is only applicable for the .Fn copyfile function.) .It Dv COPYFILE_NOFOLLOW This is a convenience macro, equivalent to .Dv (COPYFILE_NOFOLLOW_DST|COPYFILE_NOFOLLOW_SRC) . .El .Pp The .Fn copyfile_state_get and .Fn copyfile_state_set functions can be used to manipulate the .Ft copyfile_state_t object returned by .Fn copyfile_state_alloc . In both functions, the .Va dst parameter's type depends on the .Va flag parameter that is passed in. .Bl -tag -width COPYFILE_STATE_DST_FILENAME .It Dv COPYFILE_STATE_SRC_FD .It Dv COPYFILE_STATE_DST_FD Get or set the file descriptor associated with the source (or destination) file. If this has not been initialized yet, the value will be -2. The .Va dst (for .Fn copyfile_state_get ) and .Va src (for .Fn copyfile_state_set ) parameters are pointers to .Vt int . .It Dv COPYFILE_STATE_SRC_FILENAME .It Dv COPYFILE_STATE_DST_FILENAME Get or set the filename associated with the source (or destination) file. If it has not been initialized yet, the value will be .Dv NULL . For .Fn copyfile_state_set , the .Va src parameter is a pointer to a C string (i.e., .Vt char* ); .Fn copyfile_state_set makes a private copy of this string. For .Fn copyfile_state_get function, the .Va dst parameter is a pointer to a pointer to a C string (i.e., .Vt char** ); the returned value is a pointer to the .Va state 's copy, and must not be modified or released. .It Dv COPYFILE_STATE_STATUS_CB Get or set the callback status function (currently only used for recursive copies; see below for details). The .Va src parameter is a pointer to a function of type .Vt copyfile_callback_t (see above). .It Dv COPYFILE_STATE_STATUS_CTX Get or set the context parameter for the status call-back function (see below for details). The .Va src parameter is a .Vt void\ * . .It Dv COPYFILE_STATE_QUARANTINE Get or set the quarantine information with the source file. The .Va src parameter is a pointer to an opaque object (type .Vt void\ * ). .It Dv COPYFILE_STATE_COPIED Get the number of data bytes copied so far. (Only valid for .Fn copyfile_state_get ; see below for more details about callbacks.) The .Va dst parameter is a pointer to .Vt off_t (type .Vt off_t\ * ). .It Dv COPYFILE_STATE_XATTRNAME Get the name of the extended attribute during a callback for .Dv COPYFILE_COPY_XATTR (see below for details). This field cannot be set, and may be .Dv NULL . .El .Sh Recursive Copies When given the .Dv COPYFILE_RECURSIVE flag, .Fn copyfile (but not .Fn fcopyfile ) will use the .Xr fts 3 functions to recursively descend into the source file-system object. It then calls .Fn copyfile on each of the entries it finds that way. If a call-back function is given (using .Fn copyfile_state_set and .Dv COPYFILE_STATE_STATUS_CB ), the call-back function will be called four times for each directory object, and twice for all other objects. (Each directory will be examined twice, once on entry -- before copying each of the objects contained in the directory -- and once on exit -- after copying each object contained in the directory, in order to perform some final cleanup.) .Pp The call-back function will have one of the following values as the first argument, indicating what is being copied: .Bl -tag -width COPYFILE_RECURSE_DIR_CLEANUP .It Dv COPYFILE_RECURSE_FILE The object being copied is a file (or, rather, something other than a directory). .It Dv COPYFILE_RECURSE_DIR The object being copied is a directory, and is being entered. (That is, none of the filesystem objects contained within the directory have been copied yet.) .It Dv COPYFILE_RECURSE_DIR_CLEANUP The object being copied is a directory, and all of the objects contained have been copied. At this stage, the destination directory being copied will have any extra permissions that were added to allow the copying will be removed. .It Dv COPYFILE_RECURSE_ERROR There was an error in processing an element of the source hierarchy; this happens when .Xr fts 3 returns an error or unknown file type. (Currently, the second argument to the call-back function will always be .Dv COPYFILE_ERR in this case.) .El .Pp The second argument to the call-back function will indicate the stage of the copy, and will be one of the following values: .Bl -tag -width COPYFILE_FINISH .It Dv COPYFILE_START Before copying has begun. The third parameter will be a newly-created .Vt copyfile_state_t object with the call-back function and context pre-loaded. .It Dv COPYFILE_FINISH After copying has successfully finished. .It Dv COPYFILE_ERR Indicates an error has happened at some stage. If the first argument to the call-back function is .Dv COPYFILE_RECURSE_ERROR , then an error occurred while processing the source hierarchy; otherwise, it will indicate what type of object was being copied, and .Dv errno will be set to indicate the error. .El .Pp The fourth and fifth parameters are the source and destination paths that are to be copied (or have been copied, or failed to copy, depending on the second argument). .Pp The last argument to the call-back function will be the value set by .Dv COPYFILE_STATE_STATUS_CTX , if any. .Pp The call-back function is required to return one of the following values: .Bl -tag -width COPYFILE_CONTINUE .It Dv COPYFILE_CONTINUE The copy will continue as expected. .It Dv COPYFILE_SKIP This object will be skipped, and the next object will be processed. (Note that, when entering a directory. returning .Dv COPYFILE_SKIP from the call-back function will prevent the contents of the directory from being copied.) .It Dv COPYFILE_QUIT The entire copy is aborted at this stage. Any filesystem objects created up to this point will remain. .Fn copyfile will return -1, but .Dv errno will be unmodified. .El .Pp The call-back function must always return one of the values listed above; if not, the results are undefined. .Pp The call-back function will be called twice for each object (and an additional two times for directory cleanup); the first call will have a .Ar stage parameter of .Dv COPYFILE_START ; the second time, that value will be either .Dv COPYFILE_FINISH or .Dv COPYFILE_ERR to indicate a successful completion, or an error during processing. In the event of an error, the .Dv errno value will be set appropriately. .Pp The .Dv COPYFILE_PACK , .Dv COPYFILE_UNPACK , .Dv COPYFILE_MOVE , and .Dv COPYFILE_UNLINK flags are not used during a recursive copy, and will result in an error being returned. .Sh Progress Callback In addition to the recursive callbacks described above, .Fn copyfile and .Fn fcopyfile will also use a callback to report data (e.g., .Dv COPYFILE_DATA ) progress. If given, the callback will be invoked on each .Xr write 2 call. The first argument to the callback function will be .Dv COPYFILE_COPY_DATA . The second argument will either be .Dv COPYFILE_PROGRESS (indicating that the write was successful), or .Dv COPYFILE_ERR (indicating that there was an error of some sort). .Pp The amount of data bytes copied so far can be retrieved using .Fn copyfile_state_get , with the .Dv COPYFILE_STATE_COPIED requestor (the argument type is a pointer to .Vt off_t ). .Pp When copying extended attributes, the first argument to the callback function will be .Dv COPYFILE_COPY_XATTR . The other arguments will be as described for .Dv COPYFILE_COPY_DATA ; the name of the extended attribute being copied may be retrieved using .Fn copyfile_state_get and the parameter .Dv COPYFILE_STATE_XATTRNAME . When using .Dv COPYFILE_PACK , the callback may be called with .Dv COPYFILE_START for each of the extended attributes first, followed by .Dv COPYFILE_PROGRESS before getting and packing the data for each individual attribute, and then .Dv COPYFILE_FINISH when finished with each individual attribute. (That is, .Dv COPYFILE_START may be called for all of the extended attributes, before the first callback with .Dv COPYFILE_PROGRESS is invoked.) Any attribute skipped by returning .Dv COPYFILE_SKIP from the .Dv COPYFILE_START callback will not be placed into the packed output file. .Pp The return value for the data callback must be one of .Bl -tag -width COPYFILE_CONTINUE .It Dv COPYFILE_CONTINUE The copy will continue as expected. (In the case of error, it will attempt to write the data again.) .It Dv COPYFILE_SKIP The data copy will be aborted, but without error. .It Dv COPYFILE_QUIT The data copy will be aborted; in the case of .Dv COPYFILE_PROGRESS , .Dv errno will be set to .Dv ECANCELED . .El .Pp While the .Va src and .Va dst parameters will be passed in, they may be .Dv NULL in the case of .Fn fcopyfile . .Sh RETURN VALUES Except when given the .Dv COPYFILE_CHECK flag, .Fn copyfile and .Fn fcopyfile return less than 0 on error, and 0 on success. All of the other functions return 0 on success, and less than 0 on error. .Sh WARNING Both .Fn copyfile and .Fn fcopyfile can copy symbolic links; there is a gap between when the source link is examined and the actual copy is started, and this can be a potential security risk, especially if the process has elevated privileges. .Pp When performing a recursive copy, if the source hierarchy changes while the copy is occurring, the results are undefined. .Pp .Fn fcopyfile does not reset the seek position for either source or destination. This can result in the destination file being a different size than the source file. .Sh ERRORS .Fn copyfile and .Fn fcopyfile will fail if: .Bl -tag -width Er .It Bq Er EINVAL An invalid flag was passed in with .Dv COPYFILE_RECURSIVE . .It Bq Er EINVAL The .Va from or .Va to parameter to .Fn copyfile was a .Dv NULL pointer. .It Bq Er EINVAL The .Va from or .Va to parameter to .Fn copyfile was a negative number. .It Bq Er ENOMEM A memory allocation failed. .It Bq Er ENOTSUP The source file was not a directory, symbolic link, or regular file. .It Bq Er ECANCELED The copy was cancelled by callback. .El In addition, both functions may set .Dv errno via an underlying library or system call. .Sh EXAMPLES .Bd -literal -offset indent /* Initialize a state variable */ copyfile_state_t s; s = copyfile_state_alloc(); /* Copy the data and extended attributes of one file to another */ copyfile("/tmp/f1", "/tmp/f2", s, COPYFILE_DATA | COPYFILE_XATTR); /* Convert a file to an AppleDouble file for serialization */ copyfile("/tmp/f2", "/tmp/tmpfile", NULL, COPYFILE_ALL | COPYFILE_PACK); /* Release the state variable */ copyfile_state_free(s); /* A more complex way to call copyfile() */ s = copyfile_state_alloc(); copyfile_state_set(s, COPYFILE_STATE_SRC_FILENAME, "/tmp/foo"); /* One of src or dst must be set... rest can come from the state */ copyfile(NULL, "/tmp/bar", s, COPYFILE_ALL); /* Now copy the same source file to another destination file */ copyfile(NULL, "/tmp/car", s, COPYFILE_ALL); copyfile_state_free(s); /* Remove extended attributes from a file */ copyfile("/dev/null", "/tmp/bar", NULL, COPYFILE_XATTR); .Ed .Sh SEE ALSO .Xr listxattr 2 , .Xr getxattr 2 , .Xr setxattr 2 , .Xr acl 3 .Sh BUGS Both .Fn copyfile functions lack a way to set the input or output block size. .Pp Recursive copies do not honor hard links. .Sh HISTORY The .Fn copyfile API was introduced in Mac OS X 10.5.