Script to generate URL for download all files related to any record

downloadAllFileScript.apxc

string parentRecordId='0012800001IrqlyAAB';
string orgbaseUrl=URL.getSalesforceBaseUrl().toExternalForm();
string downloadAllFileUrl=orgbaseUrl+'/sfc/servlet.shepherd/version/download';
List<string> contentVersionIdList = new List<string>();
for(ContentDocumentLink cdl:[SELECT ContentDocumentId,ContentDocument.title,ContentDocument.LatestPublishedVersionId  FROM ContentDocumentLink where LinkedEntityId =:parentRecordId]){
    contentVersionIdList.add(string.valueof(cdl.ContentDocument.LatestPublishedVersionId));
}
downloadAllFileUrl = downloadAllFileUrl +'/'+string.join(contentVersionIdList,'/');
system.debug('***downloadAllFileUrl:'+downloadAllFileUrl);