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cd_idmap(3)
NAME
  cd_idmap - Sets or gets mappings of User and Group IDs on a CD-ROM

LIBRARY
  Rock Ridge and X/Open Extensions to the CDFS library (libcdrom.so,
  libcdrom.a)

SYNOPSIS
  #include <sys/cdrom.h>

  int cd_idmap (
	  char *path,
	  int cmd,
	  struct cd_idmap *idmap,
	  int *nmaps );

PARAMETERS
  *path

      Points to the mount-point of a CD-ROM File System.

  cmd

      Can be set to either {CD_SETUMAP} or {CD_SETGMAP} to set; or to
      {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.

  *idmap

      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.

  *nmaps

      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.


DESCRIPTION
  The cd_idmap routine sets or gets the mapping of UIDs or GIDs for a mounted
  CD-ROM.

RESTRICTIONS
  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.

RETURN VALUES
  If successful, the value zero is returned.
  If unsuccessful, the integer -1 is returned and errno is set to indicate
  the error.

ERRORS
  The function will fail if:

  [EACCES]  Search permission is denied for a directory in *path or read
	    permission is denied on the mount-point.

  [EFAULT]  The address of *idmap or *path is invalid.

  [EINTR]   A signal was caught during execution of the function.

  [EINVAL]  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.

  [EMFILE]  {OPEN_MAX} file descriptors are currently open in the calling
	    process.

	    [Tru64 UNIX]  Either the OPEN_MAX value or the per-process soft
	    descriptor limit is checked.

  [ENAMETOOLONG]
	    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.

  [ENFILE]  The system file table is full.

  [ENOENT]  A component of *path does not exist, or the *path argument points
	    to an empty string.

  [ENOTDIR] A component of the *path prefix is not a directory.

  [EPERM]   The user does not have the appropriate privileges to set values.

RELATED INFORMATION
  Files: cdfs/xcdr.h, sys/cdrom.h.

Index for Section 3

Alphabetical listing for C

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