shell/install/composer

#!/bin/bash
##makedesc: Install composer (latest)

echo
echo "==============================================="
echo "Installing composer (latest)..."
echo "==============================================="
echo

installed() {
    command -v "$1" >/dev/null 2>&1
}

!installed "php" && echo "WARNING: You need to have php installed"

if installed "composer"; then
    echo "WARNING: Removing current composer to install its actual version"
    sudo apt remove -y --autoremove composer
    sudo rm -f /bin/composer
    sudo rm -f /usr/bin/composer
    sudo rm -f /usr/local/bin/composer
    sudo rm -rf /usr/src/composer
fi

sudo mkdir -m 0777 -p /usr/src/composer
cd /usr/src/composer

# https://getcomposer.org/doc/faqs/how-to-install-composer-programmatically.md
EXPECTED_CHECKSUM="$(php -r 'copy("https://composer.github.io/installer.sig", "php://stdout");')"
sudo php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"
ACTUAL_CHECKSUM="$(php -r "echo hash_file('sha384', 'composer-setup.php');")"
if [ "$EXPECTED_CHECKSUM" != "$ACTUAL_CHECKSUM" ]; then
    >&2 echo 'ERROR: Invalid installer checksum'
    rm composer-setup.php
    exit 1
fi
php composer-setup.php --quiet
sudo cp /usr/src/composer/composer.phar /usr/local/bin/composer
cd - >/dev/null
sudo rm -rf /usr/src/composer/
installed "composer" && composer --version