This gets the sha1 [single] (SHA of entire mzXML file up the SHA1 node) and the filesha1 [maybe multiple] (the SHA of the original data files)

findmzXMLsha.r

# requires xml2 and magrittr

 findmzXMLsha <- function(singlemzXMLpath){
        
                  sha <- list(sha1 = NA, filesha1 = NA)
   
                   singlemzXMLpath %>% 
                      xml2::read_xml() %>% 
                      xml2::xml_ns_strip() %>% 
                      xml2::xml_find_first(., "//mzXML/sha1" ) %>%
                      xml2::xml_text() %>% 
                    return(.) -> sha$sha1
                  
                  
                   
                   
                   singlemzXMLpath %>% 
                      xml2::read_xml() %>% 
                      xml2::xml_ns_strip() %>% 
                      xml2::xml_find_all(., "//mzXML/msRun/parentFile" ) %>%
                      xml2::xml_attrs() %>% 
                      lapply(., function(x) as.character(x["fileSha1"])) %>% 
                      unlist() %>% 
                    return(.) -> sha$filesha1
                   
                   sha
 }