DouKaku?

from __future__ import with_statement
import sys
import os
import ctypes
from ctypes.util import find_library

path = sys.argv[1]
fchmod = ctypes.cdll[find_library('c')].fchmod

with os.fdopen(os.open(path,
                       os.O_CREAT|os.O_WRONLY|os.O_TRUNC,
                       0600), 'w') as fp:
    fchmod(fp.fileno(), 0600)
    print >>fp, "message in a bottle"

import System.Directory
import System.Environment
import System.IO
import System.Posix.Files

main :: IO ()
main = getArgs >>= dispatch (f,g) doesFileExist . head >>= flip setFileMode mode
  where f fp = return fp
        g fp = openFile fp WriteMode >>= hClose >> return fp

mode = foldr unionFileModes nullFileMode [ownerReadMode,ownerWriteMode]

dispatch :: (a -> IO b,a -> IO b) -> (a -> IO Bool) -> a -> IO b
dispatch (f,g) p x = p x >>= \ q -> if q then f x else g x

#!/bin/sh

filename=$1

if [ -e "$filename" ]; then
    if [ -f "$filename" ]; then
        chmod 600 "$filename"
        setfacl -b "$filename"
        setfacl -n -m u:$USER:rw "$filename"
    else
        echo "$filename is not file" 1>&2
        exit 1
    fi
else
    tmpdir=$(umask 077; mktemp -d acl.XXXXXXXX)
    (umask 077; touch "$tmpdir/$filename")
    setfacl -n -m u:$USER:rw "$tmpdir/$filename"
    mv "$tmpdir/$filename" .
    rmdir $tmpdir
fi

import java.io.*;

public class Sample {

    public static void main(String[] args) throws IOException {
        File f = new File(args[0]);
        if (!f.exists())
            f.createNewFile();            // 無ければ新規に作る
        f.setReadable(false, false);    // read権を全て削除
        f.setReadable(true, true);        // ownerのread権のみ設定
        f.setWritable(false, false);    // write権を全て削除
        f.setWritable(true, true);        // ownerのwrite権のみ設定
    }

}

| path user |
path := '/path/to/a/file'.
(FileStream newFileNamed: path) close.
user := (OSProcess thisOSProcess waitForCommandOutput: 'echo $USER') withoutTrailingBlanks.
OSProcess thisOSProcess
    waitForCommand: 'chmod 600 ', path;
    waitForCommand: 'chmod +a "everyone deny read,write" ', path;
    waitForCommand: 'chmod +a# 0 "', user, ' allow read,write" ', path

<?php
$file_name = '/tmp/test.txt';
touch($file_name);
chmod($file_name, 0600);
?>

use strict;
use warnings;
my $n;

if(-e "a.txt")
{
    print "a.txt file is already exist.\n";
    $n = chmod 0600, "a.txt";
    print "change permission to 0600\n";
} else{
    print "make new file a.txt\n";
    open NEW, ">a.txt";
    close NEW;
    $n = chmod 0600, "a.txt";
    print "change permission to 0600\n";

new File(args[0]).with{
    if (exists())
        System.exit(0);
    createNewFile()
    setReadable(false, false)
    setReadable(true, true)
    setWritable(false, false)
    setWritable(true, true)
}

#include <iostream>
#include <windows.h>
#include <aclapi.h>

// エラーメッセージ出力関数
void print_error(DWORD code)
{
    LPTSTR msg;
    FormatMessage(
        FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
        0, code, LANG_USER_DEFAULT, reinterpret_cast<LPTSTR>(&msg), 0, 0);
    std::cerr << msg << std::endl;
    LocalFree(reinterpret_cast<HLOCAL>(msg));
}

int main()
{
    PACL pacl;
    // 所有者のみ読み書きの設定
    EXPLICIT_ACCESS ea =
    {
        /* .grfAccessPermissions = */ GENERIC_READ | GENERIC_WRITE,
        /* .grfAccessMode = */ SET_ACCESS,
        /* .grfInheritance = */ NO_INHERITANCE,
        /* .Trustee = */
        {
            /* .pMultipleTrustee = */ 0,
            /* .MultipleTrusteeOperation = */ NO_MULTIPLE_TRUSTEE,
            /* .TrusteeForm = */ TRUSTEE_IS_NAME,
            /* .TrusteeType = */ TRUSTEE_IS_WELL_KNOWN_GROUP,
            /* .ptstrName = */ TEXT("CREATOR OWNER")
        },
    };
    DWORD res = SetEntriesInAcl(1, &ea, 0, &pacl);
    if (res != 0)
    {
        print_error(res);
        return 1;
    }
    // DACLを保持するセキュリティディスクプリタの作成
    PSECURITY_DESCRIPTOR psd = static_cast<PSECURITY_DESCRIPTOR>(
        malloc(SECURITY_DESCRIPTOR_MIN_LENGTH));
    if (InitializeSecurityDescriptor(psd, SECURITY_DESCRIPTOR_REVISION) == FALSE)
    {
        print_error(GetLastError());
        return 1;
    }

    if (SetSecurityDescriptorDacl(psd, TRUE, pacl, FALSE) == FALSE)
    {
        print_error(GetLastError());
        return 1;
    }
    // 上記設定を指定してファイルを作成
    SECURITY_ATTRIBUTES sa =
    {
        /*.nLength =*/ sizeof sa,
        /*.lpSecurityDescriptor =*/ psd,
        /*.bInheritHandle =*/ FALSE,
    };
    HANDLE hFile = CreateFile(TEXT("D:\\TEMP\\t.bat"), READ_CONTROL | WRITE_DAC,
        FILE_SHARE_WRITE, &sa, CREATE_ALWAYS, 0, 0);
    if (hFile == INVALID_HANDLE_VALUE)
    {
        print_error(GetLastError());
        return 1;
    }
    // ファイルが既に開かれていた場合、sa.lpSecurityDescriptorの指定が反映されないので、ここで設定している
    res = SetSecurityInfo(hFile, SE_FILE_OBJECT,
        DACL_SECURITY_INFORMATION | PROTECTED_DACL_SECURITY_INFORMATION,
        0, 0, pacl, 0);
    if (res != 0)
    {
        print_error(res);
        return 1;
    }
    CloseHandle(hFile);
    LocalFree(pacl);
    free(psd);
    return 0;
}

(asdf:operate 'asdf:load-op :osicat)
(let ((filename "foo"))
  (with-open-file (dummy filename :direction :output :if-exists :supersede)
                  (princ "bar" dummy))
  (setf (osicat:file-permissions filename) (list :user-read :user-write)))

(use file.util)
(define (main args)
  (if (file-exists? "./a.txt")
      (begin (sys-chmod "./a.txt" #o600))
      (begin (touch-file "./a.txt") (sys-chmod "./a.txt" #o600))))

filename = 'a.txt'
open(filename, 'w') { } unless File.exist?(filename)
File.chmod(0600, filename)

using System.IO;
using System.Security.AccessControl;
using System.Security.Principal;

class P
{
  static void Main(string[] args)
  {
    if (args.Length == 0) return;
    using (Stream s = File.Open
      (args[0],
      FileMode.CreateNew,
      FileAccess.Write,
      FileShare.ReadWrite))
    {
      FileSecurity sec = File.GetAccessControl(args[0]);
      IdentityReference owner = sec.GetOwner(typeof(NTAccount));
      sec.SetAccessRuleProtection(true, false);
      foreach (AuthorizationRule r
        in sec.GetAccessRules(true, true, typeof(NTAccount)))
      {
        sec.RemoveAccessRule((FileSystemAccessRule)r);
      }
      sec.AddAccessRule
        (new FileSystemAccessRule
          (owner,
          FileSystemRights.Read | FileSystemRights.Write,
          AccessControlType.Allow));
      File.SetAccessControl(args[0], sec);
    }
  }
}

let file = Sys.argv.(1) in 
let f = try open_out_gen [Open_wronly; Open_creat; Open_trunc; Open_text] 0o600 file
with Sys_error msg -> failwith ("Couldn't write to " ^ msg) in 
output_string f "OCaml\n";close_out f;;