NAME

link - A dcecp object that manages a softlink in CDS

SYNOPSIS

link create link_name_list {-to target_name [-timeout expiration_time extension_time] | -attribute attribute_list} link delete link_name_list link help [operation | -verbose] link modify link_name_list {[-add attribute_list] [-remove attribute_list] [-change attribute_list]} link operations link show link_name_list [-schema]

ARGUMENTS

link_name_list
A list of one or more names of CDS softlinks.

operationThe name of the link operation for which to display help information. 

DESCRIPTION

The link object represents a Cell Directory Service (CDS) softlink.  A softlink in CDS contains an attribute that has a name that is the same as the name of the object the softlink points to.  The softlink contains several built-in attributes, but users are free to add their own attributes.  Softlinks can point to objects, directories, and other softlinks. 

ATTRIBUTES

The following are the CDS-defined attributes that may be present in CDS link objects:

CDS_CTSSpecifies the creation timestamp (CTS) of the softlink.  The is a read-only DTS-style time stamp, which is set by the system. 

CDS_LinkTarget
Specifies the full name of the directory, object entry, or other softlink to which the softlink points.

CDS_LinkTimeout
Specifies a timeout value after which the softlink is either renewed or deleted.  Its value is a list of two elements enclosed in braces, as follows:

{expiration_time extension_time}

where:

expiration_time
Is a date and time after which CDS checks for the existence of the softlink’s target and either extends or deletes the soft link.  The value is specified in the format yyyy-mm-dd-hh:mm:ss; portions of it can be defaulted.

extension_time
Is a period of time by which to extend the softlink’s expiration time (if the server has validated that the target still exists). The value is specified in the format ddd-hh:mm:ss; portions of it can be defaulted.

CDS_UTSSpecifies the timestamp of the most recent update to an attribute of the softlink.  The value is a read-only DTS-style timestamp, which is set by the system. 

See the OSF DCE Administration Guide for more information about link attributes. 

OPERATIONS

link create

Creates a new softlink entry in CDS.  The syntax is as follows: link create link_name_list {-to target-name [-timeout expiration_time extension_time] | -attribute attribute_list} Options

-to target-name
Specifies a single name for the links to point to.  If you don’t use this option, you must specify the link target with the ­-attribute option.

-timeout expiration_time extension_time
Specifies the expiration time and extension period for all soft links named by the link-name_list argument.  The option syntax is as follows:

{expiration_time extension_time}

See ATTRIBUTES for more detailed information about link timeouts.  If you omit the ­-timeout option, the link is permanent and must be explicitly deleted. 

-attribute attribute_list
Allows you to specify attributes by using an attribute list. See ATTRIBUTES for more detailed information about link attributes.

The create operation creates a new softlink entry in CDS.  The required link_name_list argument is a list of one or more full CDS names of the soft links to be created.  This operation returns an empty string on success.  Privileges Required You must have i (insert) permission to the directory in which you intend to create the soft link.  Examples The following command creates a permanent soft link named /.:/sales/tokyo/price-server that points to an object entry named /.:/sales/east/price-server.  The expiration value indicates that CDS will check that the destination name /.:/sales/east/price-server still exists on June 25,1995, at 12:00 p.m.  If the destination name still exists, the soft link remains in effect another 90 days.  Thereafter, CDS will check that the destination name exists every 90 days. 

dcecp> link create /.:/sales/tokyo/price-server -to \\*C
> /.:/sales/east/price-server -timeout {1995-06-25-12:00:0090-00:00:00}
dcecp>

You can enter the same information as the above example by using the ­-attributes option, as follows:

dcecp> link create /.:/sales/tokyo/price-server -attribute {
> {CDS_LinkTarget /.:/sales/east/price-server} {CDS_LinkTimeout
> {expiration 1995-06-25-12:00:00} {extension 90-00:00:00}} }
dcecp>

link delete

Removes a link entry from CDS.  The syntax is as follows: link delete link_name_list The delete operation removes a link entry from CDS. This task is usually done through a client application.  The required link_name_list argument is a list of one or more full CDS names of the link entry to be removed.  This operation returns an empty string on success. Privileges Required You must have d (delete) permission to the link entry, or A (Admin) permission to the directory that stores the link entry. Examples

dcecp> link delete /.:/sales/tokyo/price-server
dcecp>

link help

Returns help information about the link object and its operations.  The syntax is as follows: link help [operation | -verbose] Options

-verboseDisplays information about the link object. 

Used without an argument or option, the link help command returns brief information about each link operation.  The optional operation argument is the name of an operation about which you want detailed information.  Alternatively, you can use the ­-verbose option for more detailed information about the link object itself.  Privileges Required No special privileges are needed to use the link help command.  Examples

dcecp> link help
create              Creates the named link.
delete              Deletes the named link.
modify              Adds, removes or changes an attribute in the named link.
show                Returns the attributes of a link.
help                Prints a summary of command-line options.
operations          Returns a list of the valid operations for this command.
dcecp>

link modify

Changes attributes in the specified softlinks.  The syntax is as follows: link modify link_name_list {[-add attribute_list] [-remove attribute_list] [-change attribute_list]} Options

-add attribute_list
Adds one or more new attributes to a softlink, or adds values to existing attributes when values are not already present.  Add an attribute type with no value by specifying an attribute type with no value.

-remove attribute_list
Removes an entire attribute, or merely some attribute values, from a softlink.  If only the attribute type is specified after the option, the entire attribute is removed.  If an attribute type and value are specified, only that value is removed.  If an attribute or value is not present, an error is returned.

-change attribute_list
Changes one attribute value to another for a softlink. Each attribute in the list has its existing value replaced by the new value given in the attribute list.  For multi-valued attributes, all existing values are replaced by all the values listed for the attribute in the attribute list.  If an attribute or value is not present, an error is returned.

The modify operation can be used to change two attributes of a softlink: CDS_LinkTarget and CDS_LinkTimeout.  The argument is a list of names of softlinks to be operated on.  The operation takes the ­-add, ­-remove, and ­-change options to specify an attribute list to describe the changes.  All the changes are performed on each softlink named in the argument.  This operation returns an empty string on success.  Privileges Required You must have w (write) permission to the link object.  Examples The following example sets the link expiration time to 1998 and the extension time to ten days and zero hours:

dcecp> link modify /.:/depts/emergency -change {
> {CDS_LinkTimeout {expiration 1998-01-20-12:00:00:00}> {extension +10-0:0:0}} }
dcecp>

link operations

Returns a list of the operations supported by the link object.  The syntax is as follows: link operations The list of available operations is in alphabetical order except for help and operations, which are listed last. Privileges Required No special privileges are needed to use the link operations command. Examples

dcecp> link operations
create delete modify show help operations
dcecp>

link show

Returns attribute information associated with specified link entries.  The syntax is as follows: link show link_name_list [-schema] Options

-schemaThis option returns whether an attribute is single or multi-valued.  This is specific to a link, meaning that the same attribute can be single-valued on one link and multi-valued on another. 

The show operation displays attribute information associated with specified link entries.  The required link_name_list argument is a list of one or more full CDS names of the soft links you want to show.  If more than one link is shown, the attributes of all the soft links are concatenated into one list.  The order of the returned attributes is the lexical order of the object identifiers (OIDs) of each attribute for each object.  Privileges Required You must have r (read) permission to the link entry.  If you specify a wildcard link entry name, you also need r (read) permission to the directory that stores the link entry.  Examples

dcecp> link show /.:/depts/emergency
{CDS_CTS 1994-07-11-17:47:59.755+00:00I0.000/00-00-c0-8a-df-56}
{CDS_UTS 1994-07-11-17:52:44.698+00:00I0.000/00-00-c0-8a-df-56}
{CDS_LinkTarget /.../my_cell.acme_health.org/depts/radiology}
{CDS_LinkTimeout
 {expiration 1995-07-11-00:00:00.000}
 {extension +10-10:00:00.000I-----}}
dcecp>
 dcecp> link show /.:/gumby -schema
{CDS-CTS single}
{CDS-UTS single}
{CDS-LinkTarget single}
dcecp>

RELATED INFORMATION

Commands:

dcecp(1m), dcecp_clearinghouse(1m), dcecp_directory(1m), dcecp_object(1m). 

Hewlett-Packard Company  —  OSF DCE 1.1/HP DCE 1.5