How to Install and Use PHP Composer on CentOS 7

 sudo yum install php-cli php-zip wget unzip

php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"

HASH="$(wget -q -O - https://composer.github.io/installer.sig)"

php -r "if (hash_file('SHA384', 'composer-setup.php') === '$HASH') { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;"

sudo php composer-setup.php --install-dir=/usr/local/bin --filename=composer

composer

Composer dependencies issues

 Error 1: Composer detected issues in your platform: Your Composer dependencies require a PHP version ">= 7.4.0"

Solution: composer install --ignore-platform-reqs

/usr/bin/env: 'php': No such file or directory CentOS Stream

sudo ln -s /usr/bin/php* /usr/bin/php

*= your current php version

How to install composer and use it on Ubuntu

sudo apt update

sudo apt install wget php-cli php-zip unzip

wget -O composer-setup.php https://getcomposer.org/installer

sudo php composer-setup.php --install-dir=/usr/local/bin --filename=composer

sudo php composer-setup.php --install-dir=/path/to/project

sudo composer self-update  

composer require nesbot/carbon

How to install Composer in MacOS

Install download the composer using the following curl command in the terminal:

curl -sS https://getcomposer.org/installer | php

 
After the command, you will have composer.phar file in the current directory and the composer command is available as: 

 php composer.phar [composer commnad] 

In order to make composer available globally, you have to move the recently downloaded composer.phar to local user’s bin folder as follow: 

sudo mv composer.phar /usr/local/bin/

 go to /usr/local/bin folder . 

You can click Shift + Command + G to open the dialog to go to folder. move the recently downloaded composer.phar in the usr/local/bin folder. 

We want to run Composer with having to be root al the time, so we need to change the permissions:

 sudo chmod 755 /usr/local/bin/composer.phar

create a alias using command:

Next, we need to let Bash know where to execute Composer:

 nano ~/.bash_profile

Add this line below to bash_profile and save

alias composer="php /usr/local/bin/composer.phar"

and then run this command:

 source ~/.bash_profile

Finally, run: composer --version

Now, you can access the composer from the terminal simply using the composer command.

Install Composer in MacOS Catalina

php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"
php -r "if (hash_file('sha384', 'composer-setup.php') === '756890a4488ce9024fc62c56153228907f1545c228516cbf63f885e036d37e9a59d27d63f46af1d4d07ee0f76181c7d3') { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;"
php composer-setup.php
php -r "unlink('composer-setup.php');"

Local or specific Directory: 

php composer-setup.php --install-dir=bin --filename=composer

Global: 

mv composer.phar /usr/local/bin/composer

Note: If the above fails due to permissions, you may need to run it again with sudo.
Note: On some versions of macOS the /usr directory does not exist by default. If you receive the error "/usr/local/bin/composer: No such file or directory" then you must create the directory manually before proceeding: mkdir -p /usr/local/bin.

You can also follow instruction from: https://getcomposer.org/download/