Write portable code that runs everywhere (Windows, Linux, Mac)

• Extends Paths.get(...) with MSYS2/Cygwin filesystem view
  • alternative to java.nio.file.Paths sees MSYS2/cygwin mounts
  • uni.Paths.get("/etc/hosts").lines.foreach(println)
• no 3rd party libraries, 100% scala.
• extended path strings are supported if mount.exe is in the PATH

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" % "0.5.2"

For scala 3.5+ or scala-cli scripts:

  "//> using dep org.vastblue:uni_3:0.6.1

• 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 cygwin64, msys64, Git-bash, etc. provide posix-like file paths. The Windows jvm can now use these filesystem abstractions.

This library provides:

• in Windows: a universal uni.Paths.get() returning a usable java.nio.file.Path object
• In all other environments uni.Paths.get() defers to java.nio.file.Paths.get()
• extensions to 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_3:0.6.1

import uni.Paths
import uni.fs.{call, posx, lines}

// display the native path and lines.size of /etc/fstab
val p = Paths.get("/etc/fstab")
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 Path#lines is empty.

• 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
• specify Windows file paths with any cygpath equivalent form
  • but prefer forward slashes except when displaying path strings
• avoid Windows syntax when specifying drive letters
  • specify paths with "/mnt/c" or "/c" rather than "C:/"
  • drive letter not needed for paths on the current working drive (e.g. C:)
  • drive-relative root is "/"
• split text on newlines using OS-agnostic regex "(\r)?\n"