.TH INTERNAL 3
.CT 2 file_io
.SH NAME
jukebox routines
.tr %"
.SH SYNOPSIS
.B "#include %hdr.h%"
.PP
.tr %%
.B "int j_shelf_to_drive(int sh, Side side, int dr, char *err)"
.PP
.B "int j_drive_to_shelf(int dr, int sh, Side side, char *err)"
.PP
.B "int j_empty_drive(int tlim, char *buf)"
.PP
.B "void j_rdshelves(char *buf)"
.PP
.B "int j_getstatus(char *buf)"
.PP
.B "int j_scsiio(struct scsi_cmd *cmd, int ncmd,"
.br
.B "\ \ \ \ \ \ struct scsi_return *ret, int nret, char *err)"
.PP
.B "int j_shelfof(char *vol_id)"
.PP
.B "int j_volid(int dr, char *err)"
.PP
.B "extern char *j_shelf[NSHELF];"
.PP
.B "extern void pperror(char *buf, char *mesg);
.SH DESCRIPTION
.I J_shelf_to_drive
places the disk in shelf
.I sh
in logical drive
.IR dr .
It returns 0 on success;
otherwise an error message is placed in
.I err .
.PP
.I J_drive_to_shelf
places the disk
in logical drive
.IR dr
in shelf
.IR sh .
If
.I sh
is negative,
the disk is returned to its home shelf.
It returns 0 on success;
otherwise an error message is placed in
.IR err .
.PP
.I J_rdshelves
initializes each element of
.I j_shelf
to the volid of the disk on that shelf.
A zero pointer means there is no disk;
a name of
.B UNALLOCATED
means the disk has not been allocated a name yet.
It returns 0 on success;
otherwise an error message is placed in
.IR err .
.PP
.I J_getstatus
initializes
.B j_status
which include the following fields:
.EX
	struct Lunstatus lun[NLUN]; /* disk status */
	uchar shelf[NSHELF];	/* shelf status */
	uchar iounit;		/* I/O unit status */
	uchar carrier;		/* carrier status */
	uchar udrive;		/* upper drive status */
	uchar ldrive;		/* lower drive status */
.EE
A return value of 0 implies success;
otherwise \-1 is returned and an error message is placed in
.IR err .
.PP
.I J_scsiio
performs a SCSI transaction.
It sends the command in
.I cmd
and
.I ncmd
data bytes and stores the return status in
.IR ret .
A return value of 0 implies success;
otherwise \-1 is returned and an error message is placed in
.IR err .
.PP
.I J_shelfof
returns the shelf number of the disk labelled
.IR vol_id .
If there is no such disk,
\-1 is returned.
.PP
.I J_volid
returns the volid of the disk on drive
.I dr
in
.IR err .
A return value of 0 implies success;
otherwise \-1 is returned and an error message is placed in
.IR err .
.PP
.I Pperror 
returns an error message that is contained in 
.IR buf.
.PP
.SH "SEE ALSO"
.SH DIAGNOSTICS