class File
- File
- IO::FileDescriptor
- IO
- Reference
- Object
Overview
A File
instance represents a file entry in the local file system and allows using it as an IO
.
file = File.new("path/to/file")
content = file.gets_to_end
file.close
# Implicit close with `open` and a block:
content = File.open("path/to/file") do |file|
file.gets_to_end
end
# Shortcut of the above:
content = File.read("path/to/file")
# Write to a file by opening with a "write mode" specified.
File.open("path/to/file", "w") do |file|
file.print "hello"
end
# Content of file on disk will now be "hello".
# Shortcut of the above:
File.write("path/to/file", "hello")
See new
for various options mode can be.
Temporary Files
Every tempfile is operated as a File
, including initializing, reading and writing.
tempfile = File.tempfile("foo")
File.size(tempfile.path) # => 6
File.info(tempfile.path).modification_time # => 2015-10-20 13:11:12 UTC
File.exists?(tempfile.path) # => true
File.read_lines(tempfile.path) # => ["foobar"]
Files created from tempfile
are stored in a directory that handles
temporary files (Dir.tempdir
):
File.tempfile("foo").path # => "/tmp/foo.ulBCPS"
It is encouraged to delete a tempfile after using it, which ensures they are not left behind in your filesystem until garbage collected.
tempfile = File.tempfile("foo")
tempfile.delete
Included Modules
- Crystal::System::File