org.sfj

Class DumbCLIParse

java.lang.Object

org.sfj.DumbCLIParse

public final class DumbCLIParse
extends Object

This is in honor of a past boss of mine, a crackerjack dev, who struggled (one time! but sadly on a projected screen... :-) ) with regular expressions. Here we have a tiny but useful command line arg parser based entirely on regular expressions. This one is for you, Louis.

The way you use this is by first call args(java.lang.String[]) with the main() args. Just gives you a list back, but feels nice for examples.

There are two ways to use it. You can use the per arg parsing methods, scanForArgWithParm(List, String) or scanForFlag(List, String, boolean) passing the arg list in. Each of the scan methods will scan the entire list, removing the first match and returning appropriately.

When you are done scanning for args, the remainder args are whatever is in the list.

Alternatively, you can pass the list to {link scanForAllFlags(List) and then scanForAllParamArgs(List) in turn, and each will return a list of matching flag or string args.

Personally, I find the incremental ones easier and more natural to code against, but some may prefer the "all" variants. See unit test for sample usage.

No one will mistake it for JCommander or any of the other full up CLI parsing packages, but very sufficient for rapid prototyping.

Author:

cschanck

Method Summary

Modifier and Type	Method and Description
static List<String>	args(String[] args) Just turn main() args into a mutable list.
static List<org.sfj.DumbCLIParse.FlagArg>	scanForAllFlags(List<String> all)
static List<org.sfj.DumbCLIParse.StringArg>	scanForAllParamArgs(List<String> all)
static Optional<String>	scanForArgWithParm(List<String> remaining, String argname) Scan for the first argument with a param name that matches the argname.
static boolean	scanForFlag(List<String> remaining, String argname, boolean foundVal) Scan for the first argument with a param name that matches the argname.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

args

public static List<String> args(String[] args)

Just turn main() args into a mutable list. Nothing exotic.

Parameters:

args - array of args

Returns:

args as mutable list.

scanForArgWithParm

public static Optional<String> scanForArgWithParm(List<String> remaining,
                                                  String argname)

Scan for the first argument with a param name that matches the argname. Scanning for arg "foo" looks for either of "--foo=thing" or "-foo=thing". Returns the arg as a string, further parsing is your problem. Note that if you want a default value, since it returns an optional, you can just do ret.orElse("default value")

Parameters:

remaining - list of remaining args to parse from

argname - name of arg, case sensitive

Returns:

Optional string value if it matched.

scanForFlag

public static boolean scanForFlag(List<String> remaining,
                                  String argname,
                                  boolean foundVal)

Scan for the first argument with a param name that matches the argname. Scanning for arg "foo" looks for any of "--foo", "--not--foo", "--not-foo", "-foo", "-not--foo", "-not-foo".

Parameters:

remaining - list of remaining args to scan through

argname - argname to scan for, case sensitive

foundVal - value to use if it is found

Returns:

If any of the variants without "not" are found, the specific foundVal will be returned. If any of the "not" variants are found, or if the flag is not seen, !foundVal will be returned.

scanForAllFlags

public static List<org.sfj.DumbCLIParse.FlagArg> scanForAllFlags(List<String> all)

scanForAllParamArgs

public static List<org.sfj.DumbCLIParse.StringArg> scanForAllParamArgs(List<String> all)