cd_idmap - sets or gets mappings of User and Group IDs on
a CD-ROM
#include <sys/cdrom.h>
int cd_idmap(
char *path,
int cmd,
struct cd_idmap *idmap,
int *nmaps );
Rock Ridge and X/Open Extensions to the CDFS library
(libcdrom.so, libcdrom.a)
Points to the mount point of a CD-ROM File System. Can be
set to either {CD_SETUMAP} or {CD_SETGMAP} to set, or
{CD_GETUMAP} or {CD_GETGMAP} to get the mappings of UIDs
or GIDs on the CD-ROM File System pointed to by *path.
The variables {CD_SETUMAP}, {CD_SETGMAP},
{CD_GETUMAP}, and {CD_GETGMAP} are defined in
cdfs/xcdr.h, an include file that is called into
sys/cdrom.h. Points to the cd_idmap structure used
-- in conjunction with the {CD_SETUMAP}, {CD_SETGMAP},
{CD_GETUMAP}, and {CD_GETGMAP} arguments to
cmd -- to hold the mappings to UIDs or GIDs. The
cd_idmap structure is defined in cdfs/xcdr.h, an
include file that is called into sys/cdrom.h.
Indicates the number of mappings declared in the
cd_idmap structure pointed to by *idmap.
If cmd is set to {CD_SETUMAP} or {CD_SETGMAP},
*nmaps overwrites any previous values set by a
prior call to cd_idmap. When *nmaps is zero, none
of the previously set mappings will stay in effect.
When calling, if cmd is set to {CD_GETUMAP} or
{CD_GETGMAP}, *nmaps must contain the maximum number
of mappings that may be returned; when returning,
*nmaps contains the number of mappings.
The cd_idmap() routine sets or gets the mapping of UIDs or
GIDs for a mounted CD-ROM.
Setting values is restricted to users with the appropriate
privileges. Only files and directories with an unrestricted
final Extended Attribute Record (XAR) are subject
to this mapping. The ISO 9660 standard does not permit a
UID or GID of zero to appear in an unrestricted XAR. Consequently,
mapping a zero value for a UID or GID may produce
unpredictable results. This function is intended to
be used to set values only directly after the CD-ROM is
mounted and before its files and directories are accessed.
Attempting to use this function to set values after files
or directories on the CD-ROM have been accessed may produce
unpredictable results.
If successful, the value zero is returned. If unsuccessful,
the integer -1 is returned and errno is set to indicate
the error.
The function will fail if: Search permission is denied for
a directory in *path or read permission is denied on the
mount-point. The address of *idmap or *path is invalid.
A signal was caught during execution of the function. The
argument *path points to a file or directory that is not
within the CD-ROM file hierarchy.
The value of cmd or *nmaps is invalid. A member of
the *idmap is invalid; for example, from_id is
larger than 65535, or a value in to_uid or to_gid
is not supported by the system. Note that this
error will not be returned when from_id does not
exist on the CD-ROM, when to_uid is not defined in
the User Database, or when to_gid is not in the
Group Database. {OPEN_MAX} file descriptors are
currently open in the calling process.
[Tru64 UNIX] Either the OPEN_MAX value or the perprocess
soft descriptor limit is checked. The
length of the *path string exceeds {PATH_MAX}, or a
pathname component is longer than {NAME_MAX} while
{_POSIX_NO_TRUNC} is in effect. The system file
table is full. A component of *path does not
exist, or the *path argument points to an empty
string. A component of the *path prefix is not a
directory. The user does not have the appropriate
privileges to set values.
Files: cdfs/xcdr.h, sys/cdrom.h
cd_idmap(3)
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