A script for switching between multiple versions of PHP.

README.md

PHP Alias

This is a BASH shell script that will,

1. Keep track of a list of PHP interpreters available.
2. Allow you to switch quickly between them.
3. Automatically switch to a different version when entering a directory.

Installation

1. Create ~/.php
2. Copy init.sh to ~/.php/init.sh
3. Add . ~/.php/init.sh to the end of .bashrc.
4. Reload your terminal.

Usage

You can get all the help information you need by running php-cfg without any arguments.

Usage: php-cfg COMMAND
Manages the `php` alias for the command line.

COMMAND

    default  Sets the default alias to use.
    define   Creates a new alias to an interpreter.
    remove   Removes an existing alias to an interpreter.
    show     Shows the real path of the alias to the interpreter.
    use      Switch to a different interpreter.

If you create a .php file in a directory, that directory will cause you to automatically switch to the interpreter defined in the file. When you leave the directory, the default interpreter is restored.

init.sh

#!/usr/bin/env bash

###
# Manages the available links and the active alias.
##
function php-cfg()
{
    # Get the command.
    local COMMAND=${1}; shift

    # Run the command.
    case ${COMMAND} in
        default) php-cfg_default "$@" ;;
        define)  php-cfg_define  "$@" ;;
        list)    php-cfg_list         ;;
        remove)  php-cfg_remove  "$@" ;;
        show)    php-cfg_show    "$@" ;;
        use)     php-cfg_use     "$@" ;;
        *)       php-cfg_usage        ;;
    esac

    return $?
}

###
# Sets the default link for the alias.
##
function php-cfg_default()
{
    local NAME=${1}

    if [ 'default' = ${NAME} ]; then
        echo "The default alias can not be itself." >&2

        return 1
    fi

    if [ ! -e ${PHP_CFG_LINK}/${NAME} ]; then
        echo "The alias does not exist." >&2

        return 1
    fi

    if [ -e ${PHP_CFG_LINK}/default ]; then
        rm ${PHP_CFG_LINK}/default
    fi

    ln -s ${PHP_CFG_LINK}/${NAME} ${PHP_CFG_LINK}/default

    return $?
}

###
# Defines a new link for the alias.
##
function php-cfg_define()
{
    local NAME=${1}
    local WHERE=${2}

    if [ -z ${NAME} ] || [ -z ${WHERE} ]; then
        cat <<'USAGE'
Usage: php-cfg define NAME PATH
Defines a new alias to a interpreter.

ARGUMENTS

    NAME  The name of the alias. (e.g. "5.6.29")
    PATH  The path to the interpreter.

USAGE
    fi

    if [ -e ${PHP_CFG_LINK}/${NAME} ]; then
        local RESPONSE=

        while [ 'y' != ${RESPONSE} ] && [ 'n' != ${RESPONSE} ]; do
            read -p 'Replace existing alias? [y/N] ' RESPONSE
        done

        if [ 'n' = ${RESPONSE} ]; then
            echo "The alias will not be replaced."

            return 0
        fi
    fi

    if [ ! -f ${WHERE} ]; then
        echo "The interpreter does not exist or is not a file." >&2

        return 1
    fi

    ln -s ${WHERE} ${PHP_CFG_LINK}/${NAME}

    return $?
}

###
# Lists the links for the alias.
##
function php-cfg_list()
{
    echo "Available interpreters:"

    while read AVAILABLE; do
        echo "  - $AVAILABLE"
    done < <(ls -1 ${PHP_CFG_LINK})

    return 0
}

###
# Updates the alias on directory change.
##
function php-cfg_prompt()
{
    if [ "$(pwd)" != "$PHP_CFG_LAST" ]; then
        if [ -f ".php" ]; then
            local NAME="$(cat .php)"

            php-cfg_use ${NAME}

            return $?
        else
            php-cfg_use
        fi
    fi

    PHP_CFG_LAST="$(pwd)"
}

###
# Removes an existing link for the alias.
##
function php-cfg_remove()
{
    local NAME=${1}

    if [ -e ${PHP_CFG_LINK}/${NAME} ]; then
        rm ${PHP_CFG_LINK}/${NAME}

        return $?
    fi

    return 0
}

###
# Shows the real path for the alias link.
##
function php-cfg_show()
{
    local NAME=${1}

    if [ ! -e ${PHP_CFG_LINK}/${NAME} ]; then
        echo "$NAME: No such alias" >&2

        return 1
    fi

    echo -n "$NAME: "

    readlink ${PHP_CFG_LINK}/${NAME}

    return $?
}

###
# Displays the usage information.
##
function php-cfg_usage()
{
    cat <<'USAGE'
Usage: php-cfg COMMAND
Manages the `php` alias for the command line.

COMMAND

    default  Sets the default alias to use.
    define   Creates a new alias to an interpreter.
    remove   Removes an existing alias to an interpreter.
    show     Shows the real path of the alias to the interpreter.
    use      Switch to a different interpreter.
USAGE
}

###
# Sets the alias to a different link.
##
function php-cfg_use()
{
    local NAME=${1}

    if [ '' = "$NAME" ]; then
        unalias php 2> /dev/null

        if [ -e ${PHP_CFG_LINK}/default ]; then
            php-cfg_use default
        fi

        return 0
    fi

    if [ ! -e ${PHP_CFG_LINK}/${NAME} ]; then
        echo "$NAME: No such interpreter" >&2

        return 1
    fi

    alias php=${PHP_CFG_LINK}/${NAME}
}

################################################################################

# Declare constants.
readonly PHP_CFG_HOME=${HOME}/.php
readonly PHP_CFG_LINK=${PHP_CFG_HOME}/link

# Make sure the links directory exists.
if [ ! -d ${PHP_CFG_LINK} ]; then
    mkdir -p ${PHP_CFG_LINK}
fi

# Set the default alias.
if [ -e ${PHP_CFG_LINK}/default ]; then
    php-cfg_use default
fi

# Update alias on directory change.
PROMPT_COMMAND="php-cfg_prompt;$PROMPT_COMMAND"