JVM - Julia Version Manager

jvm

#!/usr/bin/env bash

# Switches between various Julia versions. By default, looks for versions in
# $HOME/local/julia/, but this can be configured by setting the JVM_BIN_PREFIX
# variable. Also links the corresponding packages directory to $HOME/julia-pkgs
# for convenience.

JVM_PKG_PREFIX=${JVM_PKG_PREFIX:-"$HOME/.julia"}
JVM_BIN_PREFIX=${JVM_BIN_PREFIX:-"$HOME/local/julia"}

JBIN=""
PDIR=""

function usage() {
    echo "JVM - Julia Version Manager"
    echo ""
    echo "Usage: jvm <version>"
    echo "  version - a version string like 'v0.4' or '0.4.3'"
}

if [[ ! "$1" ]]; then
    echo "No version provided."
    echo ""
    usage
	exit 1
fi

if [[ "$1" == "-h" || "$1" == "--help" ]]; then
    usage
    exit 0
fi

# Look for the package directory
if [[ -d "$JVM_PKG_PREFIX/$1" ]]; then
	PDIR="$JVM_PKG_PREFIX/$1"
elif [[ -d "$JVM_PKG_PREFIX/v$1" ]]; then
	PDIR="$JVM_PKG_PREFIX/v$1"
else
	echo "No packages for version $1 found."
    echo ""
    usage
	exit 1
fi

# Look for the executable
if [[ -d "$JVM_BIN_PREFIX/$1" ]]; then
    JBIN="$JVM_BIN_PREFIX/$1/bin/julia"
elif [[ -d "$JVM_BIN_PREFIX/v$1" ]]; then
    JBIN="$JVM_BIN_PREFIX/v$1/bin/julia"
else
    echo "No executable for version $1 found."
    echo ""
    usage
	exit 1
fi

echo "Linking executable for version $1..."

rm "$HOME/bin/julia"
ln -s "$JBIN" "$HOME/bin/julia"

echo "Linking packages for version $1..."

rm -r "$HOME/julia-pkgs"
ln -s $PDIR "$HOME/julia-pkgs"