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cd_idmap(3) Library Functions Manual 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 Points to the mount-point of a CD-ROM File System. 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. Points to the cd_idmap structure used in conjunction with the {CD_SETUMAP}, {CD_SETGMAP}, {CD_GETUMAP}, and {CD_GETGMAP} argu- ments 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 struc- ture 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 map- pings. 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 At- tribute Record (XAR) are subject to this mapping. The ISO 9660 stan- dard 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 indi- cate the error. ERRORS 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 sup- ported 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. [DIGITAL] Either the OPEN_MAX value or the per-process soft de- scriptor limit is checked. The length of the *path string ex- ceeds {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 ap- propriate privileges to set values. RELATED INFORMATION Files: cdfs/xcdr.h, sys/cdrom.h. delim off cd_idmap(3)