> Currently, running `java` without any parameters will lead to an output that > is a full `--help`, which is over 100 lines (on my computer at least), and it > feels overwhelming. And many people might actually want to run JShell/REPL, > not the `java` launcher, but it is difficult find out about JShell. > > The proposal herein is to print a much shorter help, together with a pointer > to JShell, when the launcher does not know what to do. I.e. there is nothing > specified to start, and no option like `--help` is specified. In particular, > on my machine, it prints: > > $ java > openjdk 24-internal 2025-03-18 > > Usage: java [java options...] <application> [application arguments...] > > Where <application> is one of: > <MainClass> to execute the main method of a compiled class > -jar <JarFile>.jar to execute the main class of a JAR archive > -m <module>[/<MainClass>] to execute the main class of a module > <SourceFile>.java to compile and execute a single-file program > > Where key java options include: > --class-path <class path> > a ":"-separated list of directories and JAR archives to search for > class files > --module-path <module path> > a ":"-separated list of directories and JAR archives to search for > modules > > For more details about this launcher: java --help > For an interactive Java environment: jshell > > > Hopefully, this may be easier both for people trying to run something, and > for people that are really looking for JShell. > > What do you think? > > Thanks!
Jan Lahoda has updated the pull request incrementally with two additional commits since the last revision: - Using lowercase for the keys in the help, using 'source-file' program instead of 'single-file' program. - Using an enum instead of booleans, as suggested. ------------- Changes: - all: https://git.openjdk.org/jdk/pull/21411/files - new: https://git.openjdk.org/jdk/pull/21411/files/1791840b..5d82312f Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=21411&range=03 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21411&range=02-03 Stats: 76 lines in 2 files changed: 14 ins; 2 del; 60 mod Patch: https://git.openjdk.org/jdk/pull/21411.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/21411/head:pull/21411 PR: https://git.openjdk.org/jdk/pull/21411
