Creates a new file, or overwrites an existing file, and writes a string into it. Can also take a block just like File#open, which is yielded after the string is writ.
str = 'The content for the file' File.create('tmp/myfile.txt', str)
CREDIT: George Moschovitis
Takes a file name string and returns or changes its extension.
Without a new extension argument, returns the extension of the file name. In this respect ext is like extname, but unlike extname it does not include the dot prefix.
With a new extension argument, changes the exension of the file name to the new extension and returns it.
Examples
File.ext('file.rb') # => 'rb' File.ext('file.rb', 'txt') # => 'file.txt' File.ext('file.rb', '.txt') # => 'file.txt' File.ext('file.rb', '') # => 'file'
This method can be used with String#file for more object-oriented notation:
'file.rb'.file.ext('txt') # => 'file.txt'
CREDIT: Lavir the Whiolet
Read in a file as binary data.
Assuming we had a binary file ‘tmp/binary.dat’.
File.read_binary('tmp/binary.dat')
CREDIT: George Moschovitis
Reads in a file, removes blank lines and removes lines starting with ’#’ and then returns an array of all the remaining lines.
Thr remark indicator can be overridden via the +:omit:+ option, which can be a regualar expression or a string that is match against the start of a line.
CREDIT: Trans
Opens a file as a string and writes back the string to the file at the end of the block.
Returns the number of written bytes or nil if the file wasn‘t modified.
Note that the file will even be written back in case the block raises an exception.
Mode can either be "b" or "+" and specifies to open the file in binary mode (no mapping of the plattform‘s newlines to "\n" is done) or to append to it.
Assuming we had a file ‘message.txt’ and had a binary file ‘binary.dat’.
# Reverse contents of "message.txt" File.rewrite("tmp/message.txt") { |str| str.reverse } # Replace "foo" by "bar" in "binary.dat". File.rewrite("tmp/binary.dat", "b") { |str| str.gsub("foo", "bar") }
IMPORTANT: The old version of this method required in place modification of the file string. The new version will write whatever the block returns instead!!!
CREDIT: George Moschovitis
In place version of rewrite. This version of method requires that the string be modified in place within the block.
# Reverse contents of "message" File.rewrite("tmp/message.txt") { |str| str.reverse! } # Replace "foo" by "bar" in "binary" File.rewrite("tmp/binary.dat", "b") { |str| str.gsub!("foo", "bar") }
Returns only the first portion of the directory of a file path name.
File.rootname('lib/jump.rb') #=> 'lib' File.rootname('/jump.rb') #=> '/' File.rootname('jump.rb') #=> '.'
CREDIT: Trans
Cleans up a filename to ensure it will work on a filesystem.
File.sanitize("yo+baby!") #=> 'yo+baby_' File.sanitize(".what&up") #=> '.what_up'
CREDIT: George Moschovitis
Splits a file path into an array of individual path components. This differs from File.split, which divides the path into only two parts, directory path and basename.
File.split_all("a/b/c") #=> ['a', 'b', 'c']
CREDIT: Trans
Return the head of path from the rest of the path.
File.split_root('etc/xdg/gtk') #=> ['etc', 'xdg/gtk']
Writes the given data to the given path and closes the file. This is done in binary mode, complementing IO.read in standard Ruby.
str = 'The content for the file' File.write('tmp/write.txt', str)
Returns the number of bytes written.
CREDIT: Gavin Sinclair
Writes the given array of data to the given path and closes the file. This is done in binary mode, complementing IO.readlines in standard Ruby.
Note that readlines (the standard Ruby method) returns an array of lines with newlines intact, whereas writelines uses puts, and so appends newlines if necessary. In this small way, readlines and writelines are not exact opposites.
data = ['The content', ['for the file']] File.writelines('tmp/writelines.txt', data)
Returns number of lines written.
CREDIT: Noah Gibbs, Gavin Sinclair
File.yaml? provides a way to check if a file is a YAML formatted file:
File.yaml?('project.yaml') #=> true File.yaml?('project.xml') #=> false
Note this isn‘t perfect. At present it depends on the use use of an initial document separator (eg. ’—’). With YAML 1.1 the %YAML delaration is supposed to be manditory, so in the future this can be adapted to fit that standard.