Composer could not find a composer.json

To install composer and add to your global path:

curl -sS https://getcomposer.org/installer | phpmv composer.phar /usr/local/bin/composer

run these in terminal. It does say if you get an error that usr doesn't exist, you do need to manually make it. I know an answer was selected, so this is for anyone who may see this in the future, as i am sometimes, and don't want to be advised to visit yet another site. Its simple just two lines, might have to be in sudo if you have permission error

In my case, I did not copy all project files to the folder where I was running composer install. So do:

1. Copy your project files (including the composer.json) to folder
2. open CMD (I am using ConEmu), navigate to the new folder, run composer install from there
3. It should work or throw errors in case the json file is not correct.

If you just want to make composer run, create a new composer.json file with for example:

{    "require": {        "php": ">=5.3.2"    }}

Then run composer install.

The "Getting Started" page is the introduction to the documentation. Most documentation will start off with installation instructions, just like Composer's do.

The page that contains information on the composer.json file is located here - under "Basic Usage", the second page.

I'd recommend reading over the documentation in full, so that you gain a better understanding of how to use Composer. I'd also recommend removing what you have and following the installation instructions provided in the documentation.