Module: MkTemp

Defined in:
lib/mktemp.rb

Overview

Skeleton module for the ‘mktemp’ routine.

Ideally, one would do this in their code to import the “mktemp” call directly into their current namespace:

require 'mktemp'
include MkTemp
# do something with mktemp()

It is recommended that you look at the documentation for the mktemp() call directly for specific usage.

–

The compilation of software known as mktemp.rb is distributed under the following terms: Copyright © 2005-2006 Erik Hollensbe. All rights reserved.

Redistribution and use in source form, with or without modification, are permitted provided that the following conditions are met:

  1. Redistributions of source code must retain the above copyright

notice, this list of conditions and the following disclaimer.

THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS “AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

++

Constant Summary collapse

VALID_TMPNAM_CHARS = 
(?a..?z).to_a + (?A..?Z).to_a

Class Method Summary collapse

Class Method Details

.mktemp(filename, mask = true) ⇒ Object

This routine works similarly to mkstemp(3) in that it gets a new file, and returns a file handle for that file. The mask parameter determines whether or not to process the filename as a mask by calling the tmpnam() routine in this module. This routine will continue until it finds a valid filename, which may not do what you expect.

While all attempts have been made to keep this as secure as possible, due to a few problems with Ruby’s file handling code, we are required to allow a few concessions. If a 0-length file is created before we attempt to create ours, we have no choice but to accept it. Do not rely on this code for any expected level of security, even though we have taken all the measures we can to handle that situation.



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# File 'lib/mktemp.rb', line 87

def mktemp(filename, mask=true)
  fh = nil

  begin 
    loop do
      fn = mask ? tmpnam(filename) : filename

      if File.exist? fn
        fail "Unable to create a temporary filename" unless mask
        next
      end

      fh = File.new(fn, "a", 0600)
      fh.seek(0, IO::SEEK_END)
      break if fh.pos == 0 

      fail "Unable to create a temporary filename" unless mask
      fh.close
    end
  rescue Exception => e
    # in the case that we hit a locked file...
    fh.close if fh
    raise e unless mask
  end
  
  return fh
end

.mktempdir(filename, mask = true) ⇒ Object

Create a directory. If mask is true (default), it will use the random name generation rules from the tmpnam() call in this module.



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# File 'lib/mktemp.rb', line 123

def mktempdir(filename, mask=true)
  fn = mask ? tmpnam(filename) : filename
  Dir.mkdir(fn)
  return fn
end

.tmpnam(filename) ⇒ Object

This routine just generates a temporary file similar to the routines from ‘mktemp’. A trailing series of ‘X’ characters will be transformed into a randomly-generated set of alphanumeric characters.

This routine performs no file testing, at all. It is not suitable for anything beyond that.



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# File 'lib/mktemp.rb', line 54

def tmpnam(filename)
  m = filename.match(/(X*)$/)
  
  retnam = filename.dup
  
  if m[1]
    mask = ""
    m[1].length.times { mask += VALID_TMPNAM_CHARS[rand(52)].chr }
    retnam.sub!(/(X*)$/, mask) 
  end

  return retnam
end