jbang

#!/usr/bin/env bash

#
# To run this script remotely type this in your shell
# (where <args>... are the arguments you want to pass to Jbang):
#   curl -Ls https://sh.jbang.dev | bash -s - <args>...
#

# The Java version to install when it's not installed on the system yet
javaVersion=${JBANG_DEFAULT_JAVA_VERSION:-11}

absolute_path() {
  # if the given path to the jbang launcher is absolute (i.e. it is either starting with / or a
  # 'letter:/' when using gitbash on windows) it is returned unchanged, otherwise we construct an absolute path
  [[ $1 = /* ]] || [[ $1 =~ ^[A-z]:/ ]] && echo "$1" || echo "$PWD/${1#./}"
}

resolve_symlink() {
  if [[ $OSTYPE != darwin* ]]; then minusFarg="-f"; fi
  sym_resolved=$(readlink ${minusFarg} $1)

  if [[ -n $sym_resolved ]]; then
    echo $sym_resolved
  else
    echo $1
  fi
}

download() {
  if [ -x "$(command -v curl)" ]; then
    curl -sLf -H "Accept: application/gzip, application/octet-stream" -o "$2" $1
    retval=$?
  elif [ -x "$(command -v wget)" ]; then
    wget -q --header="Accept: application/gzip, application/octet-stream" -O "$2" $1
    retval=$?
  else
    echo "Error: curl or wget not found, please make sure one of them is installed" 1>&2
    exit 1
  fi
}

abs_jbang_path=/usr/local/Cellar/jbang/0.51.1/libexec/bin/jbang.jar

case "$(uname -s)" in
  Linux*)
    os=linux;;
  Darwin*)
    os=mac;;
  CYGWIN*|MINGW*)
    os=windows;;
  *)        echo "Unsupported Operating System: $(uname -s)" 1>&2; exit 1;;
esac

case "$(uname -m)" in
  i?86)
    arch=x32;;
  x86_64|amd64)
    arch=x64;;
  aarch64)
    arch=aarch64;;
  *)
    echo "Unsupported Architecture: $(uname -m)" 1>&2; exit 1;;
esac

## when mingw/git bash or cygwin fall out to just running the bat file.
if [[ $os == windows ]]; then
  $(dirname $abs_jbang_path)/jbang.cmd $*
  exit $?
fi

if [[ -z "$JBANG_DIR" ]]; then JBDIR="$HOME/.jbang"; else JBDIR="$JBANG_DIR"; fi
if [[ -z "$JBANG_CACHE_DIR" ]]; then TDIR="$JBDIR/cache"; else TDIR="$JBANG_CACHE_DIR"; fi

## resolve application jar path from script location
if [ -f "$(dirname $abs_jbang_path)/jbang.jar" ]; then
  jarPath=$(dirname $abs_jbang_path)/jbang.jar
elif [ -f "$(dirname $abs_jbang_path)/.jbang/jbang.jar" ]; then
  jarPath=$(dirname $abs_jbang_path)/.jbang/jbang.jar
else
  if [ ! -f "$JBDIR/bin/jbang.jar" ]; then
    echo "Downloading JBang..." 1>&2
    mkdir -p "$TDIR/urls"
    jburl="https://github.com/jbangdev/jbang/releases/latest/download/jbang.tar"
    download $jburl "$TDIR/urls/jbang.tar"
    if [ $retval -ne 0 ]; then echo "Error downloading JBang" 1>&2; exit $retval; fi
    echo "Installing JBang..." 1>&2
    rm -rf "$TDIR/urls/jbang"
    tar xf "$TDIR/urls/jbang.tar" -C "$TDIR/urls"
    if [ $retval -ne 0 ]; then echo "Error installing JBang" 1>&2; exit $retval; fi
    rm -rf "$JBDIR/bin"
    mv "$TDIR/urls/jbang/bin" "$JBDIR"
  fi
  eval "exec $JBDIR/bin/jbang $*"
fi

# Find/get a JDK
unset JAVA_EXEC
if [[ -n "$JAVA_HOME" ]]; then
  # Determine if a (working) JDK is available in JAVA_HOME
  if [ -x "$(command -v $JAVA_HOME/bin/javac)" ]; then
    JAVA_EXEC="$JAVA_HOME/bin/java";
  else
    echo "JAVA_HOME is set but does not seem to point to a valid Java JDK" 1>&2
  fi
fi
if [[ -z "$JAVA_EXEC" ]]; then
  # Determine if a (working) JDK is available on the PATH
  if [ -x "$(command -v javac)" ]; then
    JAVA_EXEC="java";
  elif [ -x "$JBDIR/currentjdk/bin/javac" ]; then
    export JAVA_HOME="$JBDIR/currentjdk"
    JAVA_EXEC="$JBDIR/currentjdk/bin/java";
  else
    export JAVA_HOME="$TDIR/jdks/$javaVersion"
    JAVA_EXEC="$JAVA_HOME/bin/java"
    # Check if we installed a JDK before
    if [ ! -d "$TDIR/jdks/$javaVersion" ]; then
      # If not, download and install it
      mkdir -p "$TDIR/jdks"
      echo "Downloading JDK $javaVersion. Be patient, this can take several minutes..." 1>&2
      jdkurl="https://api.adoptopenjdk.net/v3/binary/latest/$javaVersion/ga/$os/$arch/jdk/hotspot/normal/adoptopenjdk"
      download $jdkurl "$TDIR/bootstrap-jdk.tgz"
      if [ $retval -ne 0 ]; then echo "Error downloading JDK" 1>&2; exit $retval; fi
      echo "Installing JDK $javaVersion..." 1>&2
      rm -rf "$TDIR/jdks/$javaVersion.tmp/"
      mkdir -p "$TDIR/jdks/$javaVersion.tmp"
      tar xf "$TDIR/bootstrap-jdk.tgz" -C "$TDIR/jdks/$javaVersion.tmp" --strip-components=1
      retval=$?
      if [[ $os == mac && $retval -eq 0 ]]; then
        mv "$TDIR/jdks/$javaVersion.tmp/Contents/Home/"* "$TDIR/jdks/$javaVersion.tmp/"
        retval=$?
      fi
      if [ $retval -ne 0 ]; then
        # Check if the JDK was installed properly
        javac -version > /dev/null 2>&1
        retval=$?
      fi
      if [ $retval -ne 0 ]; then echo "Error installing JDK" 1>&2; exit $retval; fi
      # Activate the downloaded JDK giving it its proper name
      mv "$TDIR/jdks/$javaVersion.tmp" "$TDIR/jdks/$javaVersion"
      # Set the current JDK
      ${JAVA_EXEC} -classpath ${jarPath} dev.jbang.Main jdk default $javaVersion
    fi
  fi
fi

## https://stackoverflow.com/questions/1668649/how-to-keep-quotes-in-bash-arguments
## attempt to ensure each argument keeps its original quoting

## run it using command substitution to have just the user process once jbang is done
output=$(CLICOLOR_FORCE=1 ${JAVA_EXEC} ${JBANG_JAVA_OPTIONS} -classpath ${jarPath} dev.jbang.Main "$@")
err=$?
if [ $err -eq 255 ]; then
  eval "exec $output"
else
  echo "$output"
  exit $err
fi