Perl Code Examples

This section shows perl code examples for accessing exacct files.

Example 4-1 Using the Pseudocode Prototype

In typical use the Perl exacct library reads existing exacct files. Use pseudocode to show the relationships of the various Perl exacct classes. Illustrate in pseudocode the process of opening and scanning an exacct file, and processing objects of interest. In the following pseudocode, the ‘convenience’ functions are used in the interest of clarity.

-- Open the exacct file ($f is a Sun::Solaris::Exacct::File)
my $f = ea_new_file(...)

-- While not EOF ($o is a Sun::Solaris::Exacct::Object)
while (my $o = $f->get())

        -- Check to see if object is of interest
        if ($o->type() == &EO_ITEM)
             ...

        -- Retrieve the catalog ($c is a Sun::Solaris::Exacct::Catalog)
        $c = $o->catalog()

        -- Retrieve the value
        $v = $o->value();

        -- $v is a reference to a Sun::Solaris::Exacct::Group for a Group
        if (ref($v))
              ....

        -- $v is perl scalar for Items
        else

Example 4-2 Recursively dumping an exacct Object

sub dump_object
{
    my ($obj, $indent) = @_;
    my $istr = '  ' x $indent;

    #
    # Retrieve the catalog tag.  Because we are doing this in an array
    # context, the catalog tag will be returned as a (type, catalog, id) 
    # triplet, where each member of the triplet will behave as an integer
    # or a string, depending on context.  If instead this next line provided
    # a scalar context, e.g.
    #    my $cat  = $obj->catalog()->value();
    # then $cat would be set to the integer value of the catalog tag.
    #
    my @cat = $obj->catalog()->value();

    #
    # If the object is a plain item
    #
    if ($obj->type() == &EO_ITEM) {
          #
          # Note:  The '%s' formats provide s string context, so the
          # components of the catalog tag will be displayed as the
          # symbolic values.  If we changed the '%s' formats to '%d',
          # the numeric value of the components would be displayed.
          #
          printf("%sITEM\n%s  Catalog = %s|%s|%s\n", 
              $istr, $istr, @cat);
          $indent++;

          #
          # Retrieve the value of the item.  If the item contains in 
          # turn a nested exacct object (i.e. a item or group), then 
          # the value method will return a reference to the appropriate 
          # sort of perl object (Exacct::Object::Item or 
          # Exacct::Object::Group). We could of course figure out that 
          # the item contained a nested item or group by examining 
          # the catalog tag in @cat and looking for a type of 
          # EXT_EXACCT_OBJECT or EXT_GROUP.
          my $val = $obj->value();
          if (ref($val)) {
             # If it is a nested object, recurse to dump it.
             dump_object($val, $indent);
          } else {
             # Otherwise it is just a 'plain' value, so display it.
             printf("%s  Value = %s\n", $istr, $val);
          }

        #
        # Otherwise we know we are dealing with a group.  Groups represent
        # contents as a perl list or array (depending on context), so we 
        # can process the contents of the group with a 'foreach' loop, which
        # provides a list context.  In a list context the value method 
        # returns the content of the group as a perl list, which is the 
        # quickest mechanism, but doesn't allow the group to be modified. 
        # If we wanted to modify the contents of the group we could do so 
        # like this:
        #    my $grp = $obj->value();   # Returns an array reference
        #    $grp->[0] = $newitem;
        # but accessing the group elements this way is much slower.
        #
        } else {
                printf("%sGROUP\n%s  Catalog = %s|%s|%s\n",
                    $istr, $istr, @cat);
                $indent++;
                # 'foreach' provides a list context.
                foreach my $val ($obj->value()) {
                        dump_object($val, $indent);
                }
                printf("%sENDGROUP\n", $istr);
        }
}

Example 4-3 Creating a New Group Record and Writing to a File

# Prototype list of catalog tags and values.
my @items = (
   [ &EXT_STRING | &EXC_DEFAULT | &EXD_CREATOR      => "me"         ],
   [ &EXT_UINT32 | &EXC_DEFAULT | &EXD_PROC_PID     => $$           ],
   [ &EXT_UINT32 | &EXC_DEFAULT | &EXD_PROC_UID     => $<           ],
   [ &EXT_UINT32 | &EXC_DEFAULT | &EXD_PROC_GID     => $(           ],
   [ &EXT_STRING | &EXC_DEFAULT | &EXD_PROC_COMMAND => "/bin/stuff" ],
);

# Create a new group catalog object.
my $cat = new_catalog(&EXT_GROUP | &EXC_DEFAULT | &EXD_NONE);

# Create a new Group object and retrieve its data array.
my $group = new_group($cat);
my $ary = $group->value();

# Push the new Items onto the Group array.
foreach my $v (@items) {
        push(@$ary, new_item(new_catalog($v->[0]), $v->[1]));
}

# Nest the group within itself (performs a deep copy).
push(@$ary, $group);

# Dump out the group.
dump_object($group);

Example 4-4 Dumping an exacct File

#!/usr/bin/perl

use strict;
use warnings;
use blib;
use Sun::Solaris::Exacct qw(:EXACCT_ALL);

die("Usage is dumpexacct 

# Open the exact file and display the header information.
my $ef = ea_new_file($ARGV[0], &O_RDONLY) || die(error_str());
printf("Creator:  %s\n", $ef->creator());
printf("Hostname: %s\n\n", $ef->hostname());

# Dump the file contents
while (my $obj = $ef->get()) {
        ea_dump_object($obj);
}

# Report any errors
if (ea_error() != EXR_OK && ea_error() != EXR_EOF)  {
       printf("\nERROR: %s\n", ea_error_str());
       exit(1);
}
exit(0);