Running Gatsby Build via a shell script

Question

So for some context i have created a site using gatsby, that pulls data in from Wordpress' API. I figured out i can trigger a hook within wordpress to fire after a post is saved by adding this into my functions.ph p file.

add_action( 'save_post', 'fireFunctionOnSave' );
  function fireFunctionOnSave($post_id)
{
  if(wp_is_post_revision( $post_id) || wp_is_post_autosave( $post_id )) 
{
  return;
}
$old_path = getcwd();
chdir('/Applications/MAMP/htdocs/elliot-wp-gatsby/wp- 
content/themes/twentyseventeen/');
$output = shell_exec('./build.sh');
chdir($old_path);

$myfile = fopen("/Applications/MAMP/htdocs/elliot-wp-gatsby/wp- 
content/themes/twentyseventeen/output.txt", "w") or die("Unable to open 
file!");
fwrite($myfile, $output);
fclose($myfile);
}

so far it can open and run my shell script but it wont actually run gatsby build any one have any ideas? This is my shell script.

#!/bin/bash
cd /Users/elliotm/Dev-local/Projects/gatsby-wp
npm run build
echo "site built/deployed"

Thanks

Answer 1

I'm not sure shell_exec works well with bash scripts and changing directories. Please try with: exec('cd /Users/elliotm/Dev-local/Projects/gatsby-wp && npm run build') .

The && will force the exec to only execute the second part if the first one is successful.