From ebe254fa72e37b4a0a39b31c301c2a2b8815ce0c Mon Sep 17 00:00:00 2001
From: Jean Privat <jean@pryen.org>
Date: Mon, 6 Apr 2015 22:09:55 +0700
Subject: [PATCH] lib/file: some methods return a nullable Error on error

Signed-off-by: Jean Privat <jean@pryen.org>
---
 lib/standard/file.nit   |   47 ++++++++++++++++++++++++++++++++++++++---------
 lib/standard/file_nit.h |    4 ++--
 2 files changed, 40 insertions(+), 11 deletions(-)

diff --git a/lib/standard/file.nit b/lib/standard/file.nit
index 545f59b..42eca14 100644
--- a/lib/standard/file.nit
+++ b/lib/standard/file.nit
@@ -495,7 +495,7 @@ class Path
 		end
 
 		# Delete the directory itself
-		if ok then path.to_cstring.rmdir
+		if ok then ok = path.to_cstring.rmdir and ok
 
 		return ok
 	end
@@ -903,28 +903,47 @@ redef class String
 	end
 
 	# Create a directory (and all intermediate directories if needed)
-	fun mkdir
+	#
+	# Return an error object in case of error.
+	#
+	#    assert "/etc/".mkdir != null
+	fun mkdir: nullable Error
 	do
 		var dirs = self.split_with("/")
 		var path = new FlatBuffer
-		if dirs.is_empty then return
+		if dirs.is_empty then return null
 		if dirs[0].is_empty then
 			# it was a starting /
 			path.add('/')
 		end
+		var error: nullable Error = null
 		for d in dirs do
 			if d.is_empty then continue
 			path.append(d)
 			path.add('/')
-			path.to_s.to_cstring.file_mkdir
+			var res = path.to_s.to_cstring.file_mkdir
+			if not res and error == null then
+				error = new IOError("Cannot create directory `{path}`: {sys.errno.strerror}")
+			end
 		end
+		return error
 	end
 
 	# Delete a directory and all of its content, return `true` on success
 	#
 	# Does not go through symbolic links and may get stuck in a cycle if there
 	# is a cycle in the filesystem.
-	fun rmdir: Bool do return to_path.rmdir
+	#
+	# Return an error object in case of error.
+	#
+	#    assert "/fail/does not/exist".rmdir != null
+	fun rmdir: nullable Error
+	do
+		var res = to_path.rmdir
+		if res then return null
+		var error = new IOError("Cannot change remove `{self}`: {sys.errno.strerror}")
+		return error
+	end
 
 	# Change the current working directory
 	#
@@ -933,8 +952,18 @@ redef class String
 	#     "..".chdir
 	#     assert getcwd == "/"
 	#
-	# TODO: errno
-	fun chdir do to_cstring.file_chdir
+	# Return an error object in case of error.
+	#
+	#     assert "/etc".chdir == null
+	#     assert "/fail/does no/exist".chdir != null
+	#     assert getcwd == "/etc" # unchanger
+	fun chdir: nullable Error
+	do
+		var res = to_cstring.file_chdir
+		if res then return null
+		var error = new IOError("Cannot change directory to `{self}`: {sys.errno.strerror}")
+		return error
+	end
 
 	# Return right-most extension (without the dot)
 	#
@@ -1022,9 +1051,9 @@ redef class NativeString
 		return stat_element;
 	`}
 	private fun file_mkdir: Bool is extern "string_NativeString_NativeString_file_mkdir_0"
-	private fun rmdir: Bool `{ return rmdir(recv); `}
+	private fun rmdir: Bool `{ return !rmdir(recv); `}
 	private fun file_delete: Bool is extern "string_NativeString_NativeString_file_delete_0"
-	private fun file_chdir is extern "string_NativeString_NativeString_file_chdir_0"
+	private fun file_chdir: Bool is extern "string_NativeString_NativeString_file_chdir_0"
 	private fun file_realpath: NativeString is extern "file_NativeString_realpath"
 end
 
diff --git a/lib/standard/file_nit.h b/lib/standard/file_nit.h
index d8d9b4b..d86b2df 100644
--- a/lib/standard/file_nit.h
+++ b/lib/standard/file_nit.h
@@ -46,9 +46,9 @@ int file_NativeFile_NativeFile_set_buffering_type_0(FILE* f, int buf_sz, int mod
 #define file_Sys_Sys_buffer_mode_line_0(self) _IOLBF
 #define file_Sys_Sys_buffer_mode_none_0(self) _IONBF
 
-#define string_NativeString_NativeString_file_mkdir_0(p) (mkdir(p, 0777))
+#define string_NativeString_NativeString_file_mkdir_0(p) (!mkdir(p, 0777))
 #define string_NativeString_NativeString_file_getcwd_0(p) (getcwd(NULL, 0))
-#define string_NativeString_NativeString_file_chdir_0(p) (chdir(p)?-1:0) /* hack to avoid warn_unused_result */
+#define string_NativeString_NativeString_file_chdir_0(p) (!chdir(p))
 #define file_NativeString_realpath(p) (realpath(p, NULL))
 
 #define file_stdin_poll_in(self) file_stdin_poll_in_()
-- 
1.7.9.5