In this installment, we will look at parsing command-line options. We’re going to use Jon Pryor<\/a>‘s NDesk.Options<\/a> library. Since he has not made a .deb package yet, we’ll use curl to integrate NDesk.Options.cs into our codebase.<\/p>\n Updates are bolded below.<\/p>\n Updates are bolded below.<\/p>\n $<\/b> .\/Greeting.exe That about wraps up sending command line arguments to the application. Thanks to Jon for providing support for NDesk on #mono. You’re right. I should read your docs<\/a> instead of bothering you!<\/p>\n We now have a bit more complication in our build system and have something we can re-factor a bit. In the next article, we’ll start to make use of some of the autotools bits.<\/p>\n\nGet back to our workspace<\/h2>\n
$<\/b> cd ~\/src\/greeting<\/code><\/p>\nGet curl<\/h2>\n
$<\/b> sudo apt-get install curl<\/code><\/p>\nPull down a copy of NDesk.Options<\/h2>\n
$<\/b> curl "http:\/\/git.ndesk.org\/?p=ndesk-options;a=blob_plain;f=src\/NDesk.Options\/NDesk.Options\/Options.cs;hb=c52aa20569b49b620deb0fd28b19909b7c577d47" > NDesk.Options.cs<\/code><\/p>\nUpdate our Makefile<\/h2>\n
$<\/b> cat > Makefile\r\n# the first target is the one executed when no target is named\r\nall: Greeting.exe\r\n#don't do anything\r\n\r\n# running 'make clean' will execute this target\r\nclean:\r\n rm Greeting.exe\r\n\r\n# running 'make Greeting.exe' will execute this target\r\nGreeting.exe: Greeting.cs NDesk.Options.cs<\/b>\r\n# the same as gmcs -out:Greeting.exe Greeting.cs NDesk.Options.cs<\/b>\r\n gmcs -out:$@ $^\r\n<\/pre>\n
Update our C# code<\/h2>\n
$<\/b> cat > Greeting.cs\r\nusing System; \/\/ This brings in Console.Writeline, used below\r\nusing NDesk.Options; \/\/ This brings in the options parser used below<\/b>\r\n\r\nclass Greeting {\r\n private static string [] planet =\r\n { \"World\", \"Mercury\", \"Venus\", \"Earth\", \"Mars\", \"Jupiter\", \"Saturn\",\r\n \"Uranus\", \"Neptune\", \"Pluto\" };<\/b>\r\n\r\n \/\/ This is the program entry point\r\n public static int Main( string [] argv ){\r\n\r\n \/\/ default to \"World\"\r\n int planetNum = 0;\r\n\r\n \/\/ set up an option parser\r\n var p = new OptionSet () {\r\n { \"n|number=\", \"The planet number to greet\",\r\n (int v) => planetNum = (v < planet.Length ? v : 0) }\r\n };\r\n p.Parse (argv);<\/b>\r\n\r\n \/\/ A simple operation to confirm that our app is running:\r\n Console.WriteLine(\"Greetings, {0}<\/b>!\", planet[planetNum]<\/b>); \r\n\r\n \/\/ Well-behaved software returns an int from Main\r\n return 0;\r\n }\r\n}\r\n<\/pre>\nCompile<\/h2>\n
$<\/b> make<\/code><\/p>\nRun it a few times<\/h2>\n
\nGreetings, World!
\n$<\/b> .\/Greeting.exe –n 1
\nGreetings, Mercury!
\n$<\/b> .\/Greeting.exe ––number 2
\nGreetings, Venus!
\n$<\/b> .\/Greeting.exe ––number 10
\nGreetings, World!
\n$<\/b> .\/Greeting.exe –n 99
\nGreetings, World!<\/p>\nSummary<\/h3>\n