how to get a field name by field label in Drupal 7 I have added a custom field with title 'play time'. How can I get the field name(internal value) using label value in my custom module. Is there any function to get the value?
If you want to find specific content types based on field you can use: 

field_info_instances($entity_type, $bundle_name);


If you want to find any field you can use:

field_info_field_map();


In both cases you will get an array of fields and you can get field name by filtering label value.