handy scripts on macOS

.zshrc

; my handy scripts on MacOS
function realpath() {
    [[ $1 = /* ]] && echo "$1" || echo "$PWD/${1#./}"
}

function jdk_select() {
    if [ -e $1/bin/java ]; then
        P=$(realpath $1)
        export JAVA_HOME=$P
        export PATH=$JAVA_HOME/bin:$PATH
        echo "choose $P"
        java -version
    else
        echo "can't find valid jdk!"
    fi
}

function jdk_replay() {
    replay=$1
    echo "replay file $replay"
    shift
    java -XX:+ReplayCompiles -XX:+ReplayIgnoreInitErrors -XX:ReplayDataFile=$replay $*
}

function dbg_replay() {
    replay=$1
    shift
    gdb -x $HOME/hotspot.gdb --args java -XX:+ReplayCompiles -XX:+ReplayIgnoreInitErrors -XX:ReplayDataFile=$replay $*
}

#
# SSH tunneling involves in 3 hosts: local/remote, destination, bastion(aka. the ssh server, the only trusted host).
#
# Here are 2 handy functions to set up SSH tunnels where destination is the same as bastion.
# SSH can map different ports between local and destination. for simplicity, those ports are identical in my functions.
# reference: https://linuxize.com/post/how-to-setup-ssh-tunneling/

remote_fwd() {
  PORT=$1
  DEST=$2
  ssh -R ${PORT}:localhost:$PORT -N -f $DEST
}

# Local port forwarding allows you to forward a port on the local (ssh client) machine
# to a port on the remote (ssh server) machine, which is then forwarded to a port on
# the destination machine.
local_fwd() {
  PORT=$1
  DEST=$2
  ssh -L ${PORT}:localhost:$PORT -N -f $DEST
}

alias igv_fwd='remote_fwd 4444 dev'
alias http_fwd='local_fwd 8888 dev'