• Upgrades java.nio.file.Paths to recognize MSYS2/cygwin mount points.
• adds MSYS2/Cygwin filesystem view to jvm languages with only a modified import
• existing code java.nio.file.Paths.get() (returns a java.nio.file.Path object)
• no 3rd party libraries, 100% scala.
• only configuration requirement is that a Windows posix shell mount.exe is in the PATH

Run Linux and Mac jvm code with on Windows without drive letters or backslashes.

Recognizes posix file paths in Windows, via customizable mount points in C:/msys64/etc/fstab.

• Supported Scala Versions

  • scala 3.x

• Tested Target environments

  • Linux
  • Darwin/OSX
  • Windows
    • Cygwin64
    • Msys64
    • Mingw64
    • Git-bash

To use uni in an SBT project, add this dependency to build.sbt

  "org.vastblue" % "uni_3" % "0.5.0"

For scala 3.5+ or scala-cli scripts:

  "//> using dep org.vastblue:uni_3:0.5.0"

• Script as though you're running in a Linux environment.

• replace import java.nio.file.Paths with import uni.Path
• or directly call uni.Paths.get(...)
• no other changes needed (100% compatible drop in replacement for Paths.get)

• MSYS64
• CYGWIN64
• Git Bash

• Paths.get returns java.nio.file.Path objects
• Paths.get("/etc/fstab").toString == /etc/fstab in most environments
• Paths.get("/etc/fstab").toString == C:\msys64\etc\fstab (in MSYS64, for example)
• Paths.get("/etc/fstab").posx == C:/msys64/etc/fstab
• Paths.get("/etc/fstab").stdpath == /etc/fstab`

Examples below illustrate some of the capabilities.

Windows shell environments are provided by cygwin64, msys64, Git-bash, etc. However, the Windows jvm doesn't recognize the filesystem abstractions of these environments.

This library provides the missing piece.

• In Windows, a custom Paths.get() translates posix paths to Windows equivalent before calling java.nio.file.Path.get()
• In other environments it passes path strings directly to java.nio.file.Paths.get()
• convenience extension methods on java.nio.file.Path and java.io.File simplify writing portable code

The following example might surprise Windows developers, since JVM languages don't normally support posix file paths that aren't also legal Windows paths.

#!/usr/bin/env -S scala-cli shebang

//> using dep "org.vastblue::uni:0.5.0"

import uni.*
import uni.fs.*

// display the native path and lines.size of /etc/fstab
// mapped to "C:\msys64\etc\fstab" in Windows
val p = Paths.get("/etc/fstab")
printf("%s\n", p.posx)
val sysType = call("uname", "-o").getOrElse("")
printf("env: %-10s| %-22s | %d lines\n", sysType, p.posx, p.lines.size)

Linux Mint # env: GNU/Linux | shellRoot: /           | /etc/fstab            | 21 lines
Darwin     # env: Darwin    | shellRoot: /           | /etc/fstab            | 0 lines
WSL Ubuntu # env: GNU/Linux | shellRoot: /           | /etc/fstab            | 6 lines
Cygwin64   # env: Cygwin    | shellRoot: C:/cygwin64 | C:/cygwin64/etc/fstab | 24 lines
Msys64     # env: Msys      | shellRoot: C:/msys64/  | C:/msys64/etc/fstab   | 22 lines

Note that on Darwin, there is no /etc/fstab file, so the Path#lines extension returns Nil.

• Windows: install one of the following:
  • MSYS64
  • CYGWIN64
  • Git Bash
• Linux: required packages:
  • sudo apt install coreutils
• Darwin/OSX:
  • brew install coreutils

Most portability issues concern the peculiaritites of the Windows jvm. Things that maximize the odds of your script running everywhere:

• prefer scala 3
• prefer forward slashes in path Strings except when displaying output
• represent paths internally with forward slashes
• minimize reference to drive letters
  • drive letter not needed for paths on the current working drive (e.g. C:)
  • represent filesystem root as "/"
  • represent disk filesystems with "/mnt/c" or "/c" rather than "C:/"
  • uni.Paths.get() recognizes both posix and Windows filesystem paths
• When parsing input text, be OS-agnostic:
  • split Strings on newlines using regex "(\r)?\n"
• create java.nio.file.Path objects in either of two ways:
  • `uni.Paths.get("/etc/fstab")
  • "/etc/fstab".path // String extension defers to uni.Paths.get()`