MacOS X: Automatically swap php-fpm versions from brew

.bash_functions

#!/bin/sh

#
# Swaps between php-fpm versions.
# This function assumes php binaries inslatted with brew
# 
# @parameter Semplified php version number
#    (eg. PHP 5.6 is simply 56, PHP7.0 is 70 and so on...)
#
php-fpm.swap-to() {
    if [ -z "$1" ]; then
      echo "\nUsage: $0 \$php-ver\n\t(eg. $0 56 # switches to version 5.6)\n" 1>&2
      return -1;
    fi
    
    # FPM_CURRENT=$(launchctl list | grep php | awk -F'[\s\.]' '{print $3}')
    FPM_CURRENT=$(launchctl list | grep php | awk -F'[^0-9]*' '{print $3}')
    FPM_NEW="$1"

    if [ -z "$FPM_CURRENT" ]; then
        echo "\nWARNING: No current php version loaded" 1>&2
        
    elif [ "$FPM_CURRENT" = "$1" ]; then
        echo "Nothing to do, current version is already php$FPM_CURRENT"
        return 0;
        
    else
        echo "Attempting to swap between php$FPM_CURRENT and php$FPM_NEW"
    fi

    CUR_USR=$(id -u -n)
    LAUNCHAGENTS_DIR="/Users/$CUR_USR/Library/LaunchAgents"
    OPT_DIR='/usr/local/opt'
    
    CUR_PLIST_LINK="$LAUNCHAGENTS_DIR/homebrew.mxcl.php$FPM_CURRENT.plist"
    NEW_PLIST_FILE="homebrew.mxcl.php$FPM_NEW.plist"
    
    if [ ! -f "$OPT_DIR/php$FPM_NEW/$NEW_PLIST_FILE" ]; then
        echo "\nERROR: Missing php-fpm launchtl file for version: $FPM_NEW\n" 1>&2
        return -2;
    fi

    if [ ! -z $FPM_CURRENT ]; then
        echo "Unloading php-fpm $FPM_CURRENT service."
        launchctl unload -w "$CUR_PLIST_LINK"
    fi
    
    if [ -L "$CUR_PLIST_LINK" ]; then
        /bin/rm "$CUR_PLIST_LINK"
    fi

    echo "Loading php-fpm $FPM_NEW service."
    /bin/ln -s "$OPT_DIR/php$FPM_NEW/$NEW_PLIST_FILE" "$LAUNCHAGENTS_DIR/$NEW_PLIST_FILE"
    launchctl load -w "$LAUNCHAGENTS_DIR/$NEW_PLIST_FILE"
}