| Chapter 10. The Operating System Utilities (UTOS) Component | ||
|---|---|---|
 | Part II. C-Language Components |  |
Chapter 10. The Operating System Utilities (UTOS) Component
Provides the first version of types to interact with the operating system for the purpose of manageing files and directories
UTOSdirectory
Description
A UTOSdirectory object represents a directory in a file system, and gives basic access to the entries it contains. More complex management of the items represented by the entries in the directory is provided through the UTOSdirectoryentry object type. UTOSdirectory objects should be considered to be a snapshot of a directory as it was at the time the object was created as opposed than an active directory listing, since the objects are not updated when the directory contents are changed.
Type Tags
None
Object Value
The value of a UTOSdirectory object is the full specification of the directory it represents.
UTOSdirectory.new()
Description
Creates a new UTOSdirectory object for the specified directory.
Prototype
UTOSdirectory.new (
string nameerror
Parameters
| Parameter | Default value | Type name | Description |
|---|---|---|---|
| name | None | string | Specifies the directory to create an object for. This may be either partially or fully specified, the interpretation of partially specified names being dependent on the operating system. |
| error | .nul | integer |
Specifies an object which is used to output any error code generated during
creation of the UTOSdirectory object. If
error is not specified or is
.nul then any error which occurs during object
creation will halt the program. If an error object is specified and
an error occurs during object creation then the error code is
output into that object and the new method
returns .nul.
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Properties
| Property | Type | Description |
|---|---|---|
| _ | type(*) | This property is provided for use by the user to attach any object of any type to the type in which this property is provided. |
| __ | type(*) | This property is provided for use by the user to attach any object of any type to the type in which this property is provided. It has the additional feature of being marked with the resolve keyword, so that object resolution can continue down this property. |
| entrycount | integer | Gives the number of entries in the directory. An entry is either a file or a subdirectory. |
| name | string | Gives just the name of the directory, rather than the full specification of its location. |
| type | type | Specifies the UTOSdirectory type object. |
Methods
createdirectory()
Description
Creates a new subdirectory in the directory represented by the UTOSdirectory object for which the method is called. A UTOSdirectoryentry object representing the new subdirectory is returned.
Prototype
UTOSdirectoryvar.createdirectory (
string nameerror
Parameters
| Parameter | Default value | Type name | Description |
|---|---|---|---|
| name | None | string | Specifies the name of the new subdirectory. |
| error | .nul | integer |
Specifies an object which is used to output any error code generated during
creation of the subdirectory and the corresponding
UTOSdirectoryentry object. If
error is not specified or is
.nul then any error which occurs during object
creation will halt the program. If an error object is specified
and an error occurs during object creation then the error code is
output into that object and the
createdirectory method returns
.nul.
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deleteentry()
Description
Deletes an entry from the directory for which the method is called.
Prototype
UTOSdirectoryvar.deleteentry (
integer entryerror
Parameters
| Parameter | Default value | Type name | Description |
|---|---|---|---|
| entry | None | integer | Specifies the entry within the UTOSdirectory object to delete. This is given as a 1-based index. |
| error | .nul | integer |
Specifies an object which is used to output any error code generated during
deletion of the entry. If error is not
specified or is .nul then any error which
occurs during the deletion will halt the program. If an error
object is specified and an error occurs during deletion then the
error code is output into that object.
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getdirectory()
Description
Creates a new UTOSdirectory object for the directory which
contains the directory represented by the object for which this
method is called. This can be considered to be the 'parent'
directory. If there is no such directory, e.g. if the object for
which the method is called represents a root directory, then no error
is raised but .nul is returned.
Prototype
UTOSdirectoryvar.getdirectory (
integer error
Parameters
| Parameter | Default value | Type name | Description |
|---|---|---|---|
| error | .nul | integer |
Specifies an object which is used to output any error code generated during
creation of the UTOSdirectory object. If
error is not specified or is
.nul then any error which occurs during object
creation will halt the program. If an error object is specified
and an error occurs during object creation then the error code is
output into that object and the getdirectory
method returns .nul.
|
getentry()
Description
Creates a new UTOSdirectoryentry object for a specific directory entry.
Prototype
UTOSdirectoryvar.getentry (
integer entryerror
Parameters
| Parameter | Default value | Type name | Description |
|---|---|---|---|
| entry | None | integer | Specifies the entry within the UTOSdirectory object to create an object for. This is given as a 1-based index. |
| error | .nul | integer |
Specifies an object which is used to output any error code generated during
creation of the UTOSdirectoryentry object. If
error is not specified or is
.nul then any error which occurs during object
creation will halt the program. If an error object is specified
and an error occurs during object creation then the error code is
output into that object and the getentry
method returns .nul.
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