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git-svn-id: https://free-cad.svn.sourceforge.net/svnroot/free-cad/trunk@5000 e8eeb9e2-ec13-0410-a4a9-efa5cf37419d
146 lines
4.0 KiB
HTML
146 lines
4.0 KiB
HTML
<!--#include virtual="header.shtml" -->
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<CENTER><H3><FONT COLOR="#AOAO99">
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CCmdLine - a class for parsing command line with or without MFC
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</FONT></H3></CENTER><HR>
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<!-- Author and contact details -->
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This article was contributed by <A HREF="mailto:smallest@smalleranimals.com">Chris Losinger</A>.
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<!-- Environment eg NT 4.0 SP3, VC6.0 SP1 -->
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<p>Environment: All</u>
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<!-- Text / source code -->
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<p>
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<!-- The 'p' starts a paragraph of normal text -->
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CCmdLine is a simple way to parse a command line into <i>switches</i> and <i>arguments</i>.
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Ex :
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<br>
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<ul>
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MyApp.exe -sw1 arg1 arg2 -sw2 arg3 -sw3 -sw4
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</ul>
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<br>
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When using CCmdLine, "-sw1", "-sw2", "-sw3" and "-sw4" are <i>switches</i> and "arg1", "arg2" and "arg3" are <i>arguments</i>.
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<p>
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Parsing command lines with the standard C string functions (strlen, strcpy, etc.) or even
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with the CString operators is a nightmare. But, CCmdLine makes it effortless.
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<p>
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CCmdLine was written for use with console apps, but can be easily used in
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any application which requires command-line parsing.
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<p>
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CCmdLine uses STL for its collection classes, so it works in MFC
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and non-MFC apps. If you are using this in an MFC app, the switches
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and arguments will be returned as CStrings. If you are using this in a
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non-MFC app, they will be returned as STL 'string's.
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<p>
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<hr>
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Example :
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Assume the application we're writing uses a command line that has two
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required switches and two optional switches. The app should abort
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if the required switches are not present and continue with default
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values if the optional switches are not present.
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<ul>
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Sample command line :
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<br>
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<pre>
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MyApp.exe -p1 text1 text2 -p2 "this is a big argument" -opt1 -55 -opt2
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</pre>
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Switches -p1 and -p2 are required.
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<br>
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p1 has two arguments and p2 has one.
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<br>
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<br>
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Switches -opt1 and -opt2 are optional.
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<br>
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opt1 requires a numeric argument.
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<br>
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opt2 has no arguments.
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<br>
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<br>
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Also, assume that the app displays a 'help' screen if the '-h' switch
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is present on the command line.
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</ul>
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Here's how you can use CCmdLine to handle this :
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<hr>
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<!-- start a block of source code -->
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<PRE><TT><FONT COLOR="#990000">
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// if this is an MFC app, uncomment this line
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// #include "stdafx.h"
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#include "CmdLine.h"
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void main(int argc, char **argv)
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{
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// our cmd line parser object
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CCmdLine cmdLine;
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// parse the command line
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// use __argc and __argv, in MFC apps
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if (cmdLine.SplitLine(argc, argv) < 1)
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{
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// no switches were given on the command line, abort
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ASSERT(0);
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exit(-1);
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}
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// test for the 'help' case
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if (cmdLine.HasSwitch("-h"))
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{
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show_help();
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exit(0);
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}
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// StringType is CString when using MFC, else STL's 'string'
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StringType p1_1, p1_2, p2_1;
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// get the required arguments
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try
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{
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// if any of these GetArgument calls fail,
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// we'll end up in the catch() block
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// get the first -p1 argument
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p1_1 = cmdLine.GetArgument("-p1", 0);
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// get the second -p1 argument
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p1_2 = cmdLine.GetArgument("-p1", 1);
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// get the first -p2 argument
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p2_1 = cmdLine.GetArgument("-p2", 0);
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}
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catch (...)
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{
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// one of the required arguments was missing, abort
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ASSERT(0);
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exit(-1);
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}
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// get the optional parameters
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// GetSafeArgument does not throw exceptions, and allows for
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// the use of a default value, in case the switch is not found
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// convert to an int, default to '100'
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int iOpt1Val = atoi( cmdLine.GetSafeArgument( "-opt1", 0, 100 ) );
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// since opt2 has no arguments, just test for the presence of
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// the '-opt2' switch
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bool bOptSwitch2 = cmdLine.HasSwitch("-opt2");
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.... and so on....
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}
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<!-- end the block of source code -->
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</FONT></TT></PRE>
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<!-- demo project -->
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<p><A HREF="cmdline.zip">Download source - 5 Kb</A>
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<!-- Date Posted and Last update (eg August 11, 1998) -->
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<p>Date Posted: June 16, 1999
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