Feature #17295
closedFeature: Create a directory and file with Pathname#touch
Description
Right now if a developer wants to create a file and is not sure if the path exists yet or not they must:
Pathname.new("/a/b/c/d.txt").tap {|p| p.dirname.mkpath; FileUtils.touch(p)}
After this patch a developer can instead call:
Pathname.new("/a/b/c/d.txt").touch
An alternative name for this behavior could be mkfile
but I think it is confusing to have a mkfile
and a mkpath
where one creates a directory and one creates a file.
Diff:
$ git diff master
diff --git a/ext/pathname/lib/pathname.rb b/ext/pathname/lib/pathname.rb
index e6fb90277d..2ed02a6633 100644
--- a/ext/pathname/lib/pathname.rb
+++ b/ext/pathname/lib/pathname.rb
@@ -585,6 +585,27 @@ def mkpath
nil
end
+ # Creates a file and the full path to the file including any intermediate directories that don't yet
+ # exist.
+ #
+ # Example:
+ #
+ # Dir.exist?("/a/b/c") # => false
+ #
+ # p = Pathname.new("/a/b/c/d.txt")
+ # p.file? => false
+ # p.touch
+ # p.file? => true
+ #
+ # Dir.exist?("/a/b/c") # => true
+ def touch
+ require 'fileutils'
+ dirname.mkpath
+
+ FileUtils.touch(self)
+ self
+ end
+
# Recursively deletes a directory, including all directories beneath it.
#
# See FileUtils.rm_r
diff --git a/test/pathname/test_pathname.rb b/test/pathname/test_pathname.rb
index 43cef4849f..3c518cc3da 100644
--- a/test/pathname/test_pathname.rb
+++ b/test/pathname/test_pathname.rb
@@ -1394,6 +1394,14 @@ def test_mkpath
}
end
+ def test_touch
+ with_tmpchdir('rubytest-pathname') {|dir|
+ Pathname("a/b/c/d.txt").touch
+ assert_file.directory?("a/b/c")
+ assert_file.file?("a/b/c/d.txt")
+ }
+ end
+
def test_rmtree
with_tmpchdir('rubytest-pathname') {|dir|
Pathname("a/b/c/d").mkpath
Github link: https://github.com/ruby/ruby/pull/3706
Updated by hsbt (Hiroshi SHIBATA) about 3 years ago
- Status changed from Open to Assigned
- Assignee set to akr (Akira Tanaka)
Updated by Dan0042 (Daniel DeLorme) about 3 years ago
I agree having Pathname#touch
would be nice, but the issue of making sure the parent dir exists is not limited to touch
.
I often have code such as path.tap{ |p| p.dirname.mkpath }.open("a"){ ... }
So I think here it would be nice to have something like Pathname#ensure_parent_dir_exists
(but with a shorter name) that can be used in various situations:
path.ensure_parent_dir_exists.touch
path.ensure_parent_dir_exists.open('w'){...}
path.ensure_parent_dir_exists.write('w', str)
source.rename(dest.ensure_parent_dir_exists)
Updated by schneems (Richard Schneeman) about 3 years ago
For the example you gave:
path.tap{ |p| p.dirname.mkpath }.open("a"){ ... }
It looks like you want to ensure a file is created in a directory that exists. I actually think that would be a good use case for the proposed touch
. It could be shorter as:
path.touch.open("a") { ... }
I see two cases:
- Want to
mkdir -p
the parent and the path points to a file: This proposed touch interface would accommodate that. - Want to
mkdir -p
the parent and the path points to a dir: Then the dev can usemkpath
. I can't think of a situation you would want to have the parent dir created, but not the full path.
I'm not opposed to adding a specialized method that creates the parent dir, but I think that should be a separate proposal. I also think the name would need to be both specific and short-ish:
path.ensure_parent_dir_exists.open('w'){...}
path.tap{|p|p.dirname.mkpath}.open('w'){...} # Same length if you remove whitespace
I think that adding a touch
that also does mkdir -p
of the parent dir buys us the same functionality (if there's some cases I've not considered, that would be good to put into the separate proposal.
Back to this proposal, we could add a touch
that only creates the file without a mkdir -p
. But I don't know why someone would ever want to touch a file that doesn't exist. If they're wanting an error there are other ways to get it. We could also make it configurable touch(skip_mkpath: true)
, however someone can still use the regular FileUtils.touch if they want:
touch(skip_mkpath: true)
tap{|p|FileUtils.touch(p)}
Updated by knu (Akinori MUSHA) about 3 years ago
Shouldn't this method take keyword arguments that FileUtils.touch accepts?
Updated by schneems (Richard Schneeman) about 3 years ago
Shouldn't this method take keyword arguments that FileUtils.touch accepts?
I looked into it. Of the existing pathnames that delegate to FileUtils, only one supports kwargs and it does not support all of them, just one:
def mkpath(mode: nil)
This was added by nobu 16 days ago https://github.com/ruby/ruby/commit/2dd26bed86f721ed1982d00c3a0bd5ed37568e96.
I explored what it would look like to support all kwargs and wrote it up. It ended up being a little involved: https://gist.github.com/schneems/681a42ee54aa91a2185f49556469b319.
I am fine merging this and adding kwarg support as people see fit. Or if the rest of core wants it in I can add support for all the kwargs that I've described. I want to get some feedback before implementing such a change.
Pending an agreeable implementation what do you think of the opportunity to add such an interface?
Updated by Dan0042 (Daniel DeLorme) about 3 years ago
In the end I agree that touch
is enough and ensure_parent_dir_exists
is unnecessary (even with a shorter name). Even though creating the file via "touch" is kinda redundant before open('a')
it's not really a problem either.
schneems (Richard Schneeman) wrote in #note-5:
I explored what it would look like to support all kwargs and wrote it up. It ended up being a little involved: https://gist.github.com/schneems/681a42ee54aa91a2185f49556469b319.
The nocreate
option is intended to update the timestamp on an existing file. It's like "noop if file doesn't exist". So in the case the file doesn't exist, IMHO it shouldn't create the directories either.
Updated by schneems (Richard Schneeman) about 3 years ago
For what it's worth this idea isn't my favorite. I would LOVE to have a mktmpdir that returns a pathname instead of a string:
Also, this would be handy in cases:
For this touch
feature, it's a nice-to-have. What do you think about adding touch()
that just touches a file, and a kwarg that enables directory creation:
touch() # Just touches the file
touch(mkpath: true) # Touches and creates
Updated by mame (Yusuke Endoh) about 1 month ago
- Related to Feature #7361: Adding Pathname#touch added
Updated by hsbt (Hiroshi SHIBATA) about 1 month ago
- Status changed from Assigned to Rejected
Pathname#touch
is rejected at this reason.
I asked this proposal to @akr (Akira Tanaka) again, he is still negative for Pathname#touch
.