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Diffstat (limited to 'man/man3/disk.3')
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diff --git a/man/man3/disk.3 b/man/man3/disk.3 deleted file mode 100644 index bec50f20..00000000 --- a/man/man3/disk.3 +++ /dev/null @@ -1,177 +0,0 @@ -.TH DISK 3 -.SH NAME -opendisk, Disk \- generic disk device interface -.SH SYNOPSIS -.nf -.ft L -#include <u.h> -#include <libc.h> -#include <disk.h> -.ft -.PP -.ft L -typedef struct Disk { - char *prefix; - char part[NAMELEN]; - int fd, wfd, ctlfd, rdonly; - int type; - vlong secs, secsize, size, offset; - int c, h, s; -} Disk; -.ft -.PP -.B -Disk* opendisk(char *file, int rdonly, int noctl) -.SH DESCRIPTION -These routines provide a simple way to gather -and use information about -disks and disk partitions, -as well as plain files. -.PP -.I Opendisk -opens -.I file -for reading and stores the file descriptor in -the -.B fd -field of the -.B Disk -structure. -If -.I rdonly -is not set, -.I opendisk -also opens -.I file -for writing and stores that file descriptor in -.BR wfd . -The two file descriptors are kept separate to -help prevent accidents. -.PP -If -.I noctl -is not set, -.I opendisk -looks for a -.B ctl -file in the same directory as the -disk file; -if it finds one, it declares -the disk to be -an -.I sd -device, -setting the -.B type -field in the -.B Disk -structure -to -.BR Tsd . -If the passed -.I file -is named -.BI fd n disk \fR, -it looks for a file -.BI fd n ctl \fR, -and if it finds that, -declares the disk to be -a floppy disk, of type -.BR Tfloppy . -If either -control -file is found, it is opened for reading -and writing, and the resulting file descriptor -is saved as -.BR ctlfd . -Otherwise the returned disk -has type -.BR Tfile . -.PP -.I Opendisk -then stats the file and stores its length in -.BR size . -If the disk is an -.I sd -partition, -.I opendisk -reads the sector size from the -control -file and stores it in -.BR secsize ; -otherwise the sector size is assumed to be 512, -as is the case for floppy disks. -.I Opendisk -then stores the disk size measured in sectors in -.BR secs . -.PP -If the disk is an -.I sd -partition, -.I opendisk -parses the -control -file to find the partition's offset -within its disk; -otherwise it sets -.B offset -to zero. -If the disk is an ATA disk, -.I opendisk -reads -the disk geometry (number of cylinders, heads, and sectors) -from the -.B geometry -line in the -.I sd -control file; -otherwise it sets these to zero as well. -.B Name -is initialized with the base name of -the disk partition, and is useful for forming messages to the -.I sd -control file. -.B Prefix -is set to the passed filename without -the -.B name -suffix. -.PP -The IBM PC BIOS interface allocates -10 bits for the number of cylinders, 8 for -the number of heads, and 6 for the number of sectors per track. -Disk geometries are not quite so simple -anymore, but to keep the interface useful, -modern disks and BIOSes present geometries -that still fit within these constraints. -These numbers are still used when partitioning -and formatting disks. -.I Opendisk -employs a number of heuristics to discover this -supposed geometry and store it in the -.BR c , -.BR h , -and -.B s -fields. -Disk offsets in partition tables and -in FAT descriptors are stored in a form -dependent upon these numbers, so -.I opendisk -works hard to report numbers that -agree with those used by other operating -systems; the numbers bear little or no resemblance -to reality. -.SH SOURCE -.B \*9/src/libdisk/disk.c -.SH SEE ALSO -Plan 9's -\fIfloppy\fR(3) and \fIsd\fR(3) -.SH BUGS -Disks on Unix systems do not present the interface -that -.I opendisk -expects, so -.I opendisk -will give them type -.BR Tfile . |