createlabel(3)						     Library Functions Manual						    createlabel(3)

NAME

       createlabel - Creates a disk label structure for a disk device

LIBRARY

       Standard C Library (libc.a)

SYNOPSIS

       #include <sys/types.h>

       #include <sys/disklabel.h>

       int createlabel(      char *devname,	 char *name,	  struct disklabel *disk,      char *boot,	int boot_len);

PARAMETERS

       Specifies  the  device special file name of the device.	Specifies the name entry in the /etc/disktab file that is to be used for the label
       information.  Otherwise, specify NULL to indicate that the name entry either is not in the /etc/disktab file, or, if it is, that it  should
       be  ignored.  Points to the disk label structure that is filled in with the returned disk description on successful completion of the func-
       tion.  Points to the buffer that the function may use to contain the (optional) primary and secondary bootstrap names for the  disk  label.
       Specifies the length of the boot buffer.  The value must be set to the value of the BUFSIZ constant.

DESCRIPTION

       The  function fills in the disk label structure pointed to by the disk parameter.  The resulting disk label can then be written to the disk
       in order to label it.

       The function queries the device, using the devname parameter, to obtain the disk's geometry, capacity, and any default  partition  informa-
       tion.

       The  function  checks  the  name parameter.  If name is non-null, the function looks for an entry in the /etc/disktab file that matches the
       name string and initializes the disk label structure from that entry.  The function then overrides the device data and initializes the disk
       label structure from the entry in the /etc/disktab file.

       If  the	name string is NULL, or has no matching entry in the /etc/disktab file, the function queries the device (using the devname parame-
       ter) to obtain the device's name string.  The function then looks for an entry in the /etc/disktab file that matches that name string,  and
       if it finds a match, initializes the disk label structure from that entry.

       If an /etc/disktab entry indicates that the device has a dynamic geometry, the function queries the device (using the devname parameter) to
       obtain the disk's true geometry and capacity and to override any value given in an /etc/disktab entry associated with the device.  In  this
       case, any -1 lengths encountered in the partition specifications for the entry are replaced by a value equal to the device's total capacity
       minus the starting offset of the partition.

RETURN VALUES

       Upon successful completion of the createlabel function, a value of 0 is returned and the contents of the disk label structure are updated.

       Upon error, a value of -1 is returned and errno is set to [EINVAL].

ERRORS

       Either disk or boot is NULL, or boot_len is not equal to BUFSIZ.

FILES

       Table of disk partition sizes for supported disks.

RELATED INFORMATION

       Commands: disklabel(8)

       Functions: getdiskbyname(3).

       Files: disklabel(4), disktab(4) delim off

																    createlabel(3)