Command line parser

本文介绍了一个用于解析命令行参数的自定义类 CCmdLineParser,支持多种输入格式,包括键值对、长命令行和 Unicode 字符串。通过实例演示了如何使用该类进行参数解析,并提供了定制化选项,如忽略大小写、指定分隔符等。



Introduction

Getting list of arguments from command line is a common task which is required by a lot of applications. However, there is no standard solution (as far as I know ;). So I wrote class CCmdLineParser, which can parse arguments fromcommand line, if they are typed in folowing form: 

  • /Key 
  • /KeyWithValue:Value 
  • /KeyWithComplexValue:"Some really complex value of /KeyWithComplexValue"

Of course, multiple keys, Unicode and long (up to 32Kb) command lines are supported.

This implementation requires the MFC or ATL CString class, or some clone with similar interface as well as the STL class map.

Usage

First, you should construct the object and call the  Parse  function (from constructor or
CCmdLineParser parser(::GetCommandLine());
or
CCmdLineParser parser;
parser.Parse(_T("/Key /Key2:Val /Key3:\"Complex-Value\" -Key4"));

Then, there are two ways of working with results. You can check if some particular key was specified in the commandline:

if(parser.HasKey(_T("Key")) {
	// Do some stuff
}
if(parser.HasKey(_T("Key2")) {
	LPCTSTR szKey2Value = parser.GetVal(_T("Key2"));
	// Do something with value of Key2
}

LPCTSTR szKey3Value = parser.GetVal(_T("Key3"));
if(szKey3Value) {
	// There was key "Key3" in input,  
} else {
	// No key "Key3" in input
}

LPCTSTR szKey4Value = parser.GetVal(_T("Key4"));
// Key4 was found in input, but since no value was specified, 
// szKey4Value points to empty string

Another way to use is to enumerate all keys in command line:

CString sKey, sValue;

CCmdLineParser::POSITION pos = parser.getFirst();
while(!realParser.isLast(pos)) {
	realParser.getNext(pos, sKey, sValue);
	// Do something with current key and value
}

Customization and "how it works"

Repeated keys

If several different values are specified with same key, only the first value is stored. So, if user passes  command   line /Add:One /Add:Two /Add:Two  will be ignored and will not be added to parsed list.

Case sensitive/insensitive

By default, keys are  not  case-sensitive. So,  /KeyOne  is equal to  -keyONE . This is done by converting all keys to lowercase before storing them. If you want to change this behaviour, call  setCaseSensitive(true)  or call the constructor with the second argument set to true:
CCmdLineParser parser(::GetCommandLine(), true);
This will switch the parser to case-sensitive mode, and if the user passes  -key , then  GetKey(_T("Key"))  will return false

Syntax

Formally,  command   line  should be in following form:
CommandLine::=[<Key> [,<Key>...]]
<Key>::=<Delimeter>KeyName[<Separator><Value>]
<Value> ::= { KeyValue | <QuoteChar>Quoted Key Value<QuoteChar>} ][
<Delimeter>::= { - | / }
<Separator>::= { : }
<QuoteChar>::= { " }

Values for <Delimeter><Separator> and <QuoteChar> are stored in static variables m_sDelimeters,m_sValueSep and m_sQuotes respectively. If you want to change them (for instance, allow user to specify quoted values in apostrophes), you can do it in the beginning of CmdLineParser.cpp:

const TCHAR CCmdLineParser::m_sQuotes[] = _T("\"\'");
Note: If you want to change  m_sDelimeters , space must be the first character of this string. Also, if you have your own  CString  class with other name than  CString , you can change it in the beginning of  CmdLineParser.h :
typedef MyOwnCString CCmdLineParser_String;
That's it! ;)



转自:http://www.codeproject.com/Articles/2773/Command-line-parser

Introduction

Getting list of arguments from command line is a common task which is required by a lot of applications. However, there is no standard solution (as far as I know ;). So I wrote class CCmdLineParser, which can parse arguments fromcommand line, if they are typed in folowing form: 

  • /Key 
  • /KeyWithValue:Value 
  • /KeyWithComplexValue:"Some really complex value of /KeyWithComplexValue"

Of course, multiple keys, Unicode and long (up to 32Kb) command lines are supported.

This implementation requires the MFC or ATL CString class, or some clone with similar interface as well as the STL class map.

Usage

First, you should construct the object and call the  Parse  function (from constructor or
CCmdLineParser parser(::GetCommandLine());
or
CCmdLineParser parser;
parser.Parse(_T("/Key /Key2:Val /Key3:\"Complex-Value\" -Key4"));

Then, there are two ways of working with results. You can check if some particular key was specified in the commandline:

if(parser.HasKey(_T("Key")) {
	// Do some stuff
}
if(parser.HasKey(_T("Key2")) {
	LPCTSTR szKey2Value = parser.GetVal(_T("Key2"));
	// Do something with value of Key2
}

LPCTSTR szKey3Value = parser.GetVal(_T("Key3"));
if(szKey3Value) {
	// There was key "Key3" in input,  
} else {
	// No key "Key3" in input
}

LPCTSTR szKey4Value = parser.GetVal(_T("Key4"));
// Key4 was found in input, but since no value was specified, 
// szKey4Value points to empty string

Another way to use is to enumerate all keys in command line:

CString sKey, sValue;

CCmdLineParser::POSITION pos = parser.getFirst();
while(!realParser.isLast(pos)) {
	realParser.getNext(pos, sKey, sValue);
	// Do something with current key and value
}

Customization and "how it works"

Repeated keys

If several different values are specified with same key, only the first value is stored. So, if user passes  command   line /Add:One /Add:Two /Add:Two  will be ignored and will not be added to parsed list.

Case sensitive/insensitive

By default, keys are  not  case-sensitive. So,  /KeyOne  is equal to  -keyONE . This is done by converting all keys to lowercase before storing them. If you want to change this behaviour, call  setCaseSensitive(true)  or call the constructor with the second argument set to true:
CCmdLineParser parser(::GetCommandLine(), true);
This will switch the parser to case-sensitive mode, and if the user passes  -key , then  GetKey(_T("Key"))  will return false

Syntax

Formally,  command   line  should be in following form:
CommandLine::=[<Key> [,<Key>...]]
<Key>::=<Delimeter>KeyName[<Separator><Value>]
<Value> ::= { KeyValue | <QuoteChar>Quoted Key Value<QuoteChar>} ][
<Delimeter>::= { - | / }
<Separator>::= { : }
<QuoteChar>::= { " }

Values for <Delimeter><Separator> and <QuoteChar> are stored in static variables m_sDelimeters,m_sValueSep and m_sQuotes respectively. If you want to change them (for instance, allow user to specify quoted values in apostrophes), you can do it in the beginning of CmdLineParser.cpp:

const TCHAR CCmdLineParser::m_sQuotes[] = _T("\"\'");
Note: If you want to change  m_sDelimeters , space must be the first character of this string. Also, if you have your own  CString  class with other name than  CString , you can change it in the beginning of  CmdLineParser.h :
typedef MyOwnCString CCmdLineParser_String;
That's it! ;)
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