DpAppArgs 1.0.1

DpAppArgs - Organises command-line arguments into key/value pairs

Namespace: DpUtilities

Nuget Package Name: DpAppArgs

Dependencies: Package DpUtilities

Introduction

Expects an argument list in the form

[Pos1] [Pos2] ... [-xxx1 or aaa1=bbb1] ...

Where Pos1, Pos2, etc are positional arguments (ie their function is inferred by their position). For instance, if a copy operation the first argument may be the path to copy from and the second the path to copy to.

-xxx1 or aaa1=bbb1 must follow the positional arguments but thereafter may be in any sequence. For example, -overwrite convert=tolowercase.

Any argument containing a space must be enclosed in double quotes (which will be removed).

The arguments are organised into a list of type DpStringKvp (List<KeyValuePair<string, string>>) (data properties Key and Value) and the sequence is maintained.

• Positional arguments are placed in the Value, with an empty string as the Key.
• Any argument preceded by a hyphen will be placed in Key (hyphen removed) with a Value of "-".
• Arguments of the form name=value will have the name placed in Key and the value placed in Value. Note that =value is an error, whereas name= is OK (empty value).

Argument keys are case-insensitive and will be converted to lower-case. Keys must be unique within the list eg -AKey and akey=xx within the argument list would generate an error. There is no such restriction on values.

DpAppArgs

public class DpAppArgs

Constructor

public DpAppArgs (string [] argList)

argList is the argument list as supplied to the program's Main () method.

The argument list is compiled into a Key/Value pair list, accessible as property ArgList.

If any errors were found, these are included in the list with a ">" in the Key and an error message in the Value. The errors are more conveniently accessed as an array of error messages via property ErrorList and flagged by property HaveErrors.

Methods

HaveKey - Returns true if the given key exists

public bool HaveKey (string key)

where key is the key to be queried.

Returns true if the given key (case-insensitive) was in the argument list as either -key or key=xxx, otherwise false.

If the key is in the argument list, the corresponding value is retained in property LastValue, which can be retrieved at any time before the next call to HaveKey (which will overwrite it).

GetValue - Returns the value corresponding to the given key

public string? GetValue (string key)

where key is the key to be queried (case-insensitive).

If key is in the argument list, returns the corresponding value. This may be an empty string, in the case of key= and will be a dash where the key was in the form -key. If the key is not in the argument list, null is returned.

Properties

ArgList - List of all arguments

public List<DpStringKvp>? ArgList {get;}

Returns the list of (string Key/string Value) pairs corresponding to the arguments in their original sequence.

• Positional arguments are placed in the Value, with an empty string as the Key.
• Any argument preceded by a hyphen will be placed in Key (hyphen removed) with a Value of "-".
• Arguments of the form name=value will have the name placed in Key and the value placed in Value. Note that =value is an error, whereas name= is OK (empty value).
• Errors will be recorded as a ">" in the Key and an error message in Value.

Check property HaveErrors before using the argument list.

ErrorList - List of any errors found

public string []? ErrorList {get;}

Returns a string array of error messages, or an empty array.

HaveErrors - True if any errors were found

public bool HaveErrors {get}

Returns true if any errors were found by the constructor, otherwise false.

LastValue - Value corresponding to key in last call to HaveKey()

public string? LastValue {get;}

If the last call to HaveKey() returned true, the value corresponding to that key is retained in property LastValue. If not found, the property is set to null.

LastValue is only available until the next call to HaveKey(), at which point it will be overwritten.