sam_ssum(3)

NAME
     sam_ssum - Sets checksum attributes on a file

SYNOPSIS
     cc [ flag  ... ] file    ...  -L/opt/SUNWsamfs/lib  -lsam  [library ... ]

     #include "/opt/SUNWsamfs/include/lib.h"

     int sam_ssum(const char *path, const char *ops);

DESCRIPTION
     sam_ssum() sets the checksum attributes on a  file  using  a
     Sun  QFS  or SAM-QFS system call.  path is the file on which
     to set the attributes.   ops  is  the  character  string  of
     options,   for   example:   "gu".   Individual  options  are
     described below.

     If the generate (g) attribute is set (-g), a  128-bit  value
     is  generated  when  the file is archived.  When the file is
     subsequently staged, the checksum is again generated and  is
     compared  against the value generated at archive time if the
     use (-u) attribute is set.  By default, no checksum value is
     generated or used when archiving or staging a file.

     The generate attribute must be set  on  a  file  before  any
     archive  copy  has  been made.  Likewise, the selected algo-
     rithm cannot be changed after an archive copy has been made.

     Direct access and partial release are not allowed on a  file
     that  has  either of the checksum generate or use attributes
     set.  Also, it is not valid to specify that a file never  be
     archived  as  well  as  specify that a checksum be generated
     and/or used.   Therefore,  when  a  direct  access,  partial
     release,  or  archive  never  attribute  is  set  on a file,
     attempting to set the checksum generate or use attribute  on
     the  file will result in an error and the attributes will be
     unchanged.  Similarly, when either the checksum generate  or
     use  attribute  is set on a file, attempting to set a direct
     access, partial release, or archive never attribute  on  the
     file  will  result  in  an  error and the attributes will be
     unchanged.

     A file that has the checksum use  attribute  set  cannot  be
     memory  mapped.   The file also must be completely staged to
     the disk before access is allowed to the file's  data;  this
     means  that  accessing  the first byte of offline data in an
     archived file that has this attribute  set  will  be  slower
     than  accessing  the same offline file when it does not have
     this attribute set.

OPTIONS
     d    Return the file's checksum attributes to the default.

     g    Generate a checksum value for the file when archiving.

     u    Use the checksum value for the file when staging.   The
          generate  attribute  must  have been previously set, or
          must be set simultaneously.

     n    n is an integer specifying the algorithm to use to gen-
          erate  the 128-bit checksum value.  The simple checksum
          algorithm provided by Sun  Microsystems,  Inc.  is  the
          default  if  no algorithm is specified but the generate
          attribute is set.  n may be one of the following:

          0    Use no algorithm.

          1    Use a simple checksum algorithm that also  factors
               in file length.

          128 or higher
               Site-specified algorithms.

          For example, a valid options string is  "gu1",  setting
          the  generate  and  use attributes, and specifying that
          the Sun-provided simple checksum algorithm be  used  to
          generate the value.

ERRORS
     sam_ssum() fails if one or more of the following are true:

     EINVAL              An invalid option was specified, or  the
                         file  is  neither  a  regular file nor a
                         directory.

     EPERM               Not the owner or superuser.

     EFAULT              path  or  ops  points  to   an   illegal
                         address.

     EINTR               A   signal   was   caught   during   the
                         sam_ssum() function.

     ELOOP               Too many symbolic links were encountered
                         in translating path.

     ENAMETOOLONG        The length of the path argument  exceeds
                         {PATH_MAX}, or the length of a path com-
                         ponent    exceeds    {NAME_MAX}    while
                         {_POSIX_NO_TRUNC} is in effect.

     ENOENT              The named file does not exist or is  the

                         null pathname.

     ENOLINK             path points to a remote machine and  the
                         link   to  that  machine  is  no  longer
                         active.

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

SEE ALSO
     archive(1), release(1), sls(1) ssum(1), stage(1).

     sam_archive(3), sam_release(3), sam_stage(3).