> 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` executable, 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 executable 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: > > 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 source-file program > > Where key java options include: > --class-path <class path> > where <class path> is a list of directories and JAR archives to search > for class files, separated by ":" > --module-path <module path> > where <module path> is a list of directories and JAR archives to search > for modules, separated by ":" > > For additional help on usage: 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 with a new target base due to a merge or a rebase. The pull request now contains 14 commits: - Merge branch 'master' into JDK-8340133-2 - - suffixing <jarfile> and <sourcefile> with .jar and .java in both the concise and full help. - using a stderr version instead of the stdout version. - Reflecting review feedback: - using "conciseVersionString" intead of "shortVersionString" - using <jarfile>.jar <jarfile> - Merge branch 'master' into JDK-8340133-2 - Using correct pplaceholders. - Adjusting text as suggested. - Cleaning up the concise message: - using 2 spaces instead of 4, - rewording the "for more use --help" part of the message as suggested to avoid the word "launcher". - 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. - Adjusting the concise help as suggested: 'using main class of a JAR archive' and '<JarFile>.jar'/'<SourceFile>.java' - ... and 4 more: https://git.openjdk.org/jdk/compare/dfddbcaa...439fa40f ------------- Changes: https://git.openjdk.org/jdk/pull/21411/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21411&range=08 Stats: 124 lines in 6 files changed: 63 ins; 2 del; 59 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
