What are some common reasons for PHP scripts not running properly on the command line?

One common reason for PHP scripts not running properly on the command line is that the PHP executable may not be in the system's PATH variable. To solve this issue, you can specify the full path to the PHP executable when running the script.

#!/usr/bin/php
<?php
// Your PHP script code here
```

Another reason could be that the script is missing the appropriate shebang line at the beginning of the file. Adding the shebang line will ensure that the script is executed using the PHP interpreter.

```php
#!/usr/bin/php
<?php
// Your PHP script code here