main linux adaptation: mangling of atrtibute names which under linux (only?) require a namespace as prefix

NAMESPACE

@@ -16,6 +16,7 @@ export(set_xattr)
 importFrom(Rcpp,sourceCpp)
 importFrom(magrittr,"%>%")
 importFrom(sys,exec_internal)
+importFrom(utils,sessionInfo)
 importFrom(xml2,as_list)
 importFrom(xml2,read_xml)
 useDynLib(xattrs)

R/util.R

@@ -41,3 +41,53 @@ convert_plist <- function(path) {
   }
 
 }
+
+
+# Linux: attributes are prefixed with a namespace, that is, 
+# an attribute has the form: namespace.attribute 
+# Examples: user.mime_type, trusted.md5sum, system.posix_acl_access
+# for xattrs, the interest is primarily to access the user
+# namespace. When a namespace is missing, "user" is used as namespace.
+# https://linux.die.net/man/5/attr
+#
+# Removing the namespace "user" from attribute names used in 
+# parameters or when listing attributes enables to use the same
+# R code across platforms
+
+linux_namespaces <- c("user", "security", "system", "trusted")
+
+#' handle_user_prefix_param
+#' @param stringvector vector of strings with attribute names
+#' @return stringvector adjusted with required namespace (Linux)
+#' @keywords internal
+#' @importFrom utils sessionInfo
+handle_user_prefix_param <- function(stringvector){
+
+  # vectorised function to work on linux where attribute
+  # name are to be prefixed with "user." for parameters 
+  
+  if(grepl("linux", sessionInfo()$platform)) {
+    unname(sapply(stringvector, function(x) 
+      ifelse(grepl(paste0("^(", paste0(linux_namespaces, collapse = "|"), ")[.]"), x), x, paste0("user.", x))))
+  } else {
+    stringvector
+  }
+}
+
+#' handle_user_prefix_return
+#' @param stringvector vector of strings with attribute names
+#' @return stringvector adjusted without namespace (Linux)
+#' @keywords internal
+#' @importFrom utils sessionInfo
+handle_user_prefix_return <- function(stringvector){
+
+  # vectorised function to work on linux where from
+  # attribute names the prefix "user." should be removed
+  
+  if(grepl("linux", sessionInfo()$platform)) {
+    unname(sapply(stringvector, function(x) ifelse(grepl("^user.", x), sub("^user.(.*)$", "\\1", x))))
+  } else {
+    stringvector
+  }
+}
+

man/handle_user_prefix_param.Rd

@@ -0,0 +1,18 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/util.R
+\name{handle_user_prefix_param}
+\alias{handle_user_prefix_param}
+\title{handle_user_prefix_param}
+\usage{
+handle_user_prefix_param(stringvector)
+}
+\arguments{
+\item{stringvector}{vector of strings with attribute names}
+}
+\value{
+stringvector adjusted with required namespace (Linux)
+}
+\description{
+handle_user_prefix_param
+}
+\keyword{internal}

man/handle_user_prefix_return.Rd

@@ -0,0 +1,18 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/util.R
+\name{handle_user_prefix_return}
+\alias{handle_user_prefix_return}
+\title{handle_user_prefix_return}
+\usage{
+handle_user_prefix_return(stringvector)
+}
+\arguments{
+\item{stringvector}{vector of strings with attribute names}
+}
+\value{
+stringvector adjusted without namespace (Linux)
+}
+\description{
+handle_user_prefix_return
+}
+\keyword{internal}