Rosetta Code

File modification time

Revision as of 19:27, 30 May 2015 by rosettacode>Gerard Schildberger (→‎{{header|REXX}}: added the REXX language.)

This task will attempt to get and set the modification time of a file.

Task
File modification time
You are encouraged to solve this task according to the task description, using any language you may know.
Task
File modification time
You are encouraged to solve this task according to the task description, using any language you may know.

Ada

Ada does not allow you to change the date of a file but you can definitely read it: <lang ada>with Ada.Directories; use Ada.Directories; with Ada.Text_IO; use Ada.Text_IO; with Ada.Calendar.Formatting; use Ada.Calendar.Formatting;

procedure File_Time_Test is begin 

  Put_Line (Image (Modification_Time ("file_time_test.adb")));

end File_Time_Test;</lang>

AutoHotkey

<lang AutoHotkey>FileGetTime, OutputVar, output.txt MsgBox % OutputVar FileSetTime, 20080101, output.txt FileGetTime, OutputVar, output.txt MsgBox % OutputVar</lang>

AWK

Works with: gawk

<lang awk>@load "filefuncs" BEGIN { 

   name = "input.txt"

   # display time
   stat(name, fd)
   printf("%s\t%s\n", name, strftime("%a %b %e %H:%M:%S %Z %Y", fd["mtime"]) )

   # change time
   cmd = "touch -t 201409082359.59 " name
   system(cmd)
   close(cmd)

}</lang>

Non-GNU awk's don't have direct access to the filesystem but can execute system-commands.

<lang awk>#!/bin/awk -f BEGIN { # file modification time on Unix, using stat 

  fn ="input.txt"

  cmd="stat " fn
  print "#", cmd
  system(cmd)            # just execute cmd

  cmd="stat -c %Y " fn   # seconds since the epoch
  print "#", cmd
  system(cmd)

  cmd="stat -c %y " fn   # human-readable format
  print "#", cmd
  system(cmd)

  print "##"
  cmd | getline x        # get output from cmd
 #print x
  close(cmd)
  
  n=split(x,stat," ")
 #for (i in stat) { print i, stat[i] }
  print "file:", fn
  print "date:", stat[1], "time:", stat[2]
      1. change filetime with touch:
  cmd="touch -t 201409082359.59 " fn
  print "#", cmd; system(cmd)
  
  cmd="stat " fn
  print "#", cmd; system(cmd)

}</lang>

Output:
# stat input.txt
  File: `input.txt'
  Size: 126       	Blocks: 8          IO Block: 4096   regular file
Device: 700h/1792d	Inode: 2195620     Links: 1
Access: (0644/-rw-r--r--)  Uid: (   48/  apache)   Gid: (   48/  apache)
Access: 2014-11-05 20:18:39.000000000 -0600
Modify: 2014-11-05 20:18:39.000000000 -0600
Change: 2014-11-05 20:18:39.000000000 -0600
# stat -c %Y input.txt
1415240319
# stat -c %y input.txt
2014-11-05 20:18:39.000000000 -0600
##
file: input.txt
date: 2014-11-05 time: 20:18:39.000000000
See also

File modification time#Batch_File, #Run_BASIC, #UNIX_Shell

Batch File

Works with: Windows NT version 4

<lang dos>for %%f in (file.txt) do echo.%%~tf</lang> The date/time format is dependent on the user's locale, like the contents of the %DATE% and %TIME% built-ins. There is no built-in way of setting a file's modification time.

BBC BASIC

Works with: BBC BASIC for Windows

<lang bbcbasic> DIM ft{dwLowDateTime%, dwHighDateTime%} 

     DIM st{wYear{l&,h&}, wMonth{l&,h&}, wDayOfWeek{l&,h&}, \
     \      wDay{l&,h&}, wHour{l&,h&}, wMinute{l&,h&}, \
     \      wSecond{l&,h&}, wMilliseconds{l&,h&} }
     
     REM File is assumed to exist:
     file$ = @tmp$ + "rosetta.tmp"
     
     REM Get and display the modification time:
     file% = OPENIN(file$)
     SYS "GetFileTime", @hfile%(file%), 0, 0, ft{}
     CLOSE #file%
     SYS "FileTimeToSystemTime", ft{}, st{}
     date$ = STRING$(16, CHR$0)
     time$ = STRING$(16, CHR$0)
     SYS "GetDateFormat", 0, 0, st{}, 0, date$, LEN(date$) TO N%
     date$ = LEFT$(date$, N%-1)
     SYS "GetTimeFormat", 0, 0, st{}, 0, time$, LEN(time$) TO N%
     time$ = LEFT$(time$, N%-1)
     PRINT date$ " " time$
     
     REM Set the modification time to the current time:
     SYS "GetSystemTime", st{}
     SYS "SystemTimeToFileTime", st{}, ft{}
     file% = OPENUP(file$)
     SYS "SetFileTime", @hfile%(file%), 0, 0, ft{}
     CLOSE #file%

</lang>

C

POSIX utime()

utime() has a precision of one second. This program would truncate the time to the last second, losing precision if the filesystem is more precise.

Library: POSIX

<lang c>#include <sys/stat.h>

  1. include <stdio.h>
  2. include <time.h>
  3. include <utime.h>

const char *filename = "input.txt";

int main() { 

 struct stat foo;
 time_t mtime;
 struct utimbuf new_times;

 if (stat(filename, &foo) < 0) {
   perror(filename);
   return 1;
 }
 mtime = foo.st_mtime; /* seconds since the epoch */

 new_times.actime = foo.st_atime; /* keep atime unchanged */
 new_times.modtime = time(NULL);    /* set mtime to current time */
 if (utime(filename, &new_times) < 0) {
   perror(filename);
   return 1;
 }

 return 0;

}</lang>

BSD utimes()

With BSD, utime() is obsolete. utimes() has a precision of 1 microsecond (where 1 second = 1000000 microseconds).

Library: BSD libc

<lang c>#include <sys/stat.h>

  1. include <sys/time.h>
  2. include <err.h>

const char *filename = "input.txt";

int main() { 

 struct stat foo;
 struct timeval new_times[2];

 if (stat(filename, &foo) < 0)
   err(1, "%s", filename);

 /* keep atime unchanged */
 TIMESPEC_TO_TIMEVAL(&new_times[0], &foo.st_atim);

 /* set mtime to current time */
 gettimeofday(&new_times[1], NULL);

 if (utimes(filename, new_times) < 0)
   err(1, "%s", filename);

 return 0;

}</lang>

POSIX utimensat()

utimensat(2) has a precision of 1 nanosecond (where 1 second = 10**9 nanoseconds). Program needs to be linked with -lrt.

Library: POSIX
Works with: POSIX version -1.2008

<lang c>#include <sys/stat.h>

  1. include <sys/time.h>
  2. include <time.h>
  3. include <fcntl.h>
  4. include <stdio.h>

const char *filename = "input.txt";

int main() { 

 struct stat foo;
 struct timespec new_times[2];

 if (stat(filename, &foo) < 0) {
   perror(filename);
   return 1;
 }

 /* keep atime unchanged */
 new_times[0] = foo.st_atim;

 /* set mtime to current time */
 clock_gettime(CLOCK_REALTIME, &new_times[1]);

 if (utimensat(AT_FDCWD, filename, new_times, 0) < 0) {
   perror(filename);
   return 1;
 }

 return 0;

}</lang>

Windows

Declare FILETIME modtime; and then use GetFileTime(fh, NULL, NULL, &modtime); to get the file modification time, or SetFileTime(fh, NULL, NULL, &modtime); to set it.

Library: Win32

<lang c>#include <windows.h>

  1. include <stdio.h>
  2. include <stdlib.h>
  3. include <wchar.h>

/* Print "message: last Win32 error" to stderr. */ void oops(const wchar_t *message) { wchar_t *buf; DWORD error;

buf = NULL; error = GetLastError(); FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, error, 0, (wchar_t *)&buf, 0, NULL);

if (buf) { fwprintf(stderr, L"%ls: %ls", message, buf); LocalFree(buf); } else { /* FormatMessageW failed. */ fwprintf(stderr, L"%ls: unknown error 0x%x\n", message, error); } }

int setmodtime(const wchar_t *path) { FILETIME modtime; SYSTEMTIME st; HANDLE fh; wchar_t date[80], time[80];

fh = CreateFileW(path, GENERIC_READ | FILE_WRITE_ATTRIBUTES, 0, NULL, OPEN_EXISTING, 0, NULL); if (fh == INVALID_HANDLE_VALUE) { oops(path); return 1; }

/* * Use GetFileTime() to get the file modification time. */ if (GetFileTime(fh, NULL, NULL, &modtime) == 0) goto fail; FileTimeToSystemTime(&modtime, &st); if (GetDateFormatW(LOCALE_USER_DEFAULT, DATE_LONGDATE, &st, NULL, date, sizeof date / sizeof date[0]) == 0 || GetTimeFormatW(LOCALE_USER_DEFAULT, 0, &st, NULL, time, sizeof time / sizeof time[0]) == 0) goto fail; wprintf(L"%ls: Last modified at %s at %s (UTC).\n", path, date, time);

/* * Use SetFileTime() to change the file modification time * to the current time. */ GetSystemTime(&st); if (GetDateFormatW(LOCALE_USER_DEFAULT, DATE_LONGDATE, &st, NULL, date, sizeof date / sizeof date[0]) == 0 || GetTimeFormatW(LOCALE_USER_DEFAULT, 0, &st, NULL, time, sizeof time / sizeof time[0]) == 0) goto fail; SystemTimeToFileTime(&st, &modtime); if (SetFileTime(fh, NULL, NULL, &modtime) == 0) goto fail; wprintf(L"%ls: Changed to %s at %s (UTC).\n", path, date, time);

CloseHandle(fh); return 0;

fail: oops(path); CloseHandle(fh); return 1; }

/* 

* Show the file modification time, and change it to the current time.
*/

int main() { int argc, i, r; wchar_t **argv;

/* MinGW never provides wmain(argc, argv). */ argv = CommandLineToArgvW(GetCommandLineW(), &argc); if (argv == NULL) { oops(L"CommandLineToArgvW"); exit(1); }

if (argc < 2) { fwprintf(stderr, L"usage: %ls file...\n", argv[0]); exit(1); }

r = 0; for (i = 1; argv[i] != NULL; i++) if (setmodtime(argv[i])) r = 1; return r; }</lang>

C++

compiled with g++ -lboost_filesystem <sourcefile> -o <destination file> <lang cpp>#include <boost/filesystem/operations.hpp>

  1. include <ctime>
  2. include <iostream>

int main( int argc , char *argv[ ] ) { 

  if ( argc != 2 ) {
     std::cerr << "Error! Syntax: moditime <filename>!\n" ;
     return 1 ;
  }
  boost::filesystem::path p( argv[ 1 ] ) ;
  if ( boost::filesystem::exists( p ) ) {
     std::time_t t = boost::filesystem::last_write_time( p ) ;
     std::cout << "On " << std::ctime( &t ) << " the file " << argv[ 1 ]

<< " was modified the last time!\n" ; 

     std::cout << "Setting the modification time to now:\n" ;
     std::time_t n = std::time( 0 ) ;
     boost::filesystem::last_write_time( p , n ) ; 
     t = boost::filesystem::last_write_time( p ) ;
     std::cout << "Now the modification time is " << std::ctime( &t ) << std::endl ;
     return 0 ;
  } else {
     std::cout << "Could not find file " << argv[ 1 ] << '\n' ;
     return 2 ;
  }

}</lang>

C#

<lang csharp>using System; using System.IO;

Console.WriteLine(File.GetLastWriteTime("file.txt")); File.SetLastWriteTime("file.txt", DateTime.Now);</lang>

Clojure

<lang lisp>(import '(java.io File) 

       '(java.util Date))

(Date. (.lastModified (File. "output.txt"))) (Date. (.lastModified (File. "docs")))

(.setLastModified (File. "output.txt") 

                 (.lastModified (File. "docs")))</lang>

Common Lisp

Common Lisp doesn't provide a way to set the modification time. The write date can be accessed, however, using file-write-date:

<lang lisp>(file-write-date "input.txt")</lang>

Implementations may, in addition, provide other ways of accessing these file attributes, e.g., POSIX bindings:

Works with: SBCL

(1.0.30, OS X, Intel),

Translation of: C

(sb-posix:utime takes an access time and a modification time rather than an array of two times.)

<lang lisp>(let* ((filename "input.txt") 

      (stat (sb-posix:stat filename))
      (mtime (sb-posix:stat-mtime stat)))
 (sb-posix:utime filename

(sb-posix:stat-atime stat) (sb-posix:time)))</lang>

D

<lang d>import std.stdio; import std.file: getTimes, setTimes, SysTime;

void main() { 

   auto fname = "unixdict.txt";
   SysTime fileAccessTime, fileModificationTime;
   getTimes(fname, fileAccessTime, fileModificationTime);
   writeln(fileAccessTime, "\n", fileModificationTime);
   setTimes(fname, fileAccessTime, fileModificationTime);

}</lang> For Windows systems there is also getTimesWin(), that gives the file creation time too.

Delphi

<lang Delphi>procedure GetModifiedDate(const aFilename: string): TDateTime; var 

 hFile: Integer;
 iDosTime: Integer;

begin 

 hFile := FileOpen(aFilename, fmOpenRead);
 iDosTime := FileGetDate(hFile);
 FileClose(hFile);
 if (hFile = -1) or (iDosTime = -1) then raise Exception.Create('Cannot read file: ' + sFilename);
 Result := FileDateToDateTime(iDosTime);

end;

procedure ChangeModifiedDate(const aFilename: string; aDateTime: TDateTime); begin 

 FileSetDate(aFileName, DateTimeToFileDate(aDateTime));

end;</lang>

E

Works with: E-on-Java
Translation of: Java

E follows the Java File interface, except that it replaces boolean success/failure returns with an ejector parameter, so that the default behavior if the client does not handle the case is not to continue ignoring the failure.

<lang e>def strdate(date) { 

 return E.toString(<unsafe:java.util.makeDate>(date))

}

def test(type, file) { 

   def t := file.lastModified()
   println(`The following $type called ${file.getPath()} ${
           if (t == 0) { "does not exist." } else { `was modified at ${strdate(t)}` }}`)
   println(`The following $type called ${file.getPath()} ${
           escape ne { file.setLastModified(timer.now(), ne); "was modified to current time." } catch _ { "does not exist." }}`)
   println(`The following $type called ${file.getPath()} ${
           escape ne { file.setLastModified(t, ne); "was modified to previous time." } catch _ { "does not exist." }}`)

}

test("file", <file:output.txt>) test("directory", <file:docs>)</lang>

Emacs Lisp

<lang Lisp>(nth 5 (file-attributes "input.txt")) ;; mod date+time

(set-file-times "input.txt") ;; to current-time (set-file-times "input.txt" 

               (encode-time 0 0 0  1 1 2014)) ;; to given date+time</lang>

set-file-times sets both the access time and modification time of the file. Time values are in the usual Emacs list form. Emacs file name handler magic applies to both file-attributes and set-file-times so they can act on "remote" files too.

File visiting buffers record the modification time of the file so as to guard against changes by another program. set-file-times from within Emacs doesn't update those buffer times and so looks like an external change.

Erlang

<lang Erlang> -module( file_modification_time ).

-include_lib("kernel/include/file.hrl").

-export( [task/0] ).

task() -> 

      File = "input.txt",
      {ok, File_info} = file:read_file_info( File ),
      io:fwrite( "Modification time ~p~n", [File_info#file_info.mtime] ),
      ok = file:write_file_info( File, File_info#file_info{mtime=calendar:local_time()} ).

</lang>

F#

<lang fsharp>open System open System.IO

[<EntryPoint>] let main args = 

   Console.WriteLine(File.GetLastWriteTime(args.[0]))
   File.SetLastWriteTime(args.[0], DateTime.Now)
   0</lang>

Factor

<lang factor>"foo.txt" file-info modified>> .</lang> Setting the modified time is not cross-platform, so here's a Unix version. <lang factor>USE: io.files.info.unix

"foo.txt" now 2 hours time+ set-file-modified-time</lang>

Go

<lang go>package main

import ( 

   "fmt"
   "os"
   "syscall"
   "time"

)

var filename = "input.txt"

func main() { 

   foo, err := os.Stat(filename)
   if err != nil {
       fmt.Println(err)
       return
   }
   fmt.Println("mod time was:", foo.ModTime())
   mtime := time.Now()
   atime := mtime // a default, because os.Chtimes has an atime parameter.
   // but see if there's a real atime that we can preserve.
   if ss, ok := foo.Sys().(*syscall.Stat_t); ok {
       atime = time.Unix(ss.Atim.Sec, ss.Atim.Nsec)
   }
   os.Chtimes(filename, atime, mtime)
   fmt.Println("mod time now:", mtime)

}</lang>

GUISS

In Graphical User Interface Support Script, we can can only use facilities that the underlying user interface provides, so we can display file timestamps, but cannot alter them. In this example, we get the date and timestamp for the file Foobar.txt.

<lang guiss>Start,My Documents,Rightclick:Icon:Foobar.txt,Properties</lang>

Haskell

<lang haskell>import System.Posix.Files import System.Posix.Time

do status <- getFileStatus filename 

  let atime = accessTime status
      mtime = modificationTime status -- seconds since the epoch
  curTime <- epochTime
  setFileTimes filename atime curTime -- keep atime unchanged
                                      -- set mtime to current time</lang>

Alternative (only gets modification time): <lang haskell>import System.Directory import System.Time

do ct <- getModificationTime filename 

  cal <- toCalendarTime ct
  putStrLn (calendarTimeToString cal)</lang>

HicEst

<lang hicest>CHARACTER timestamp*18

timestamp = ' ' ! blank timestamp will read: SYSTEM(FIle="File_modification_time.hic", FileTime=timestamp) ! 20100320141940.525

timestamp = '19991231235950' ! set timestamp to Millenium - 10 seconds SYSTEM(FIle="File_modification_time.hic", FileTime=timestamp)</lang>

Icon and Unicon

Icon doesn't support 'stat' or 'utime'; however, information can be obtained by use of the system function to access command line. <lang Unicon> every dir := !["./","/"] do { 

  if i := stat(f := dir || "input.txt") then {
     write("info for ",f ," mtime= ",ctime(i.mtime),", atime=",ctime(i.ctime), ", atime=",ctime(i.atime)) 
     utime(f,i.atime,i.mtime-1024)
     i := stat(f)
     write("update for ",f ," mtime= ",ctime(i.mtime),", atime=",ctime(i.ctime), ", atime=",ctime(i.atime)) 
     }      
  else stop("failure to stat ",f)
  }</lang>

Notes:

  • Icon and Unicon accept both / and \ for directory separators.
  • 'ctime' formats an integer representing an epoch time into human readable form
  • 'utime' updates the atime and mtime values

J

The standard file access library only supports reading the file modification time. <lang j> load 'files' 

  fstamp 'input.txt'

2009 8 24 20 34 30</lang> It is possible to set the time but it has to be done through OS specific external calls.

Java

<lang java>import java.io.File; import java.util.Date; public class FileModificationTimeTest { 

  public static void test(String type, File file) {
      long t = file.lastModified();
      System.out.println("The following " + type + " called " + file.getPath() +
           (t == 0 ? " does not exist." : " was modified at " + new Date(t).toString() )
      );
      System.out.println("The following " + type + " called " + file.getPath() + 
           (!file.setLastModified(System.currentTimeMillis()) ? " does not exist." : " was modified to current time." )
      );
      System.out.println("The following " + type + " called " + file.getPath() + 
           (!file.setLastModified(t) ? " does not exist." : " was modified to previous time." )
      );
  }
  public static void main(String args[]) {
      test("file", new File("output.txt"));
      test("directory", new File("docs"));
  }

}</lang>

JavaScript

Works with: JScript

Get only. <lang javascript>var fso = new ActiveXObject("Scripting.FileSystemObject"); var f = fso.GetFile('input.txt'); var mtime = f.DateLastModified;</lang> The following works in all browsers, including IE10. <lang javascript>var file = document.getElementById("fileInput").files.item(0); var last_modified = file.lastModifiedDate;</lang>

Julia

<lang Julia> fname = "fool.txt" tfmt = "%FT%T%z"

println("The modification time of ", fname, " is ") println(" ", strftime(tfmt, mtime(fname)))

println("\nTouch this file.") touch(fname)

println("The modification time of ", fname, " is now ") println(" ", strftime(tfmt, mtime(fname))) </lang>

Output:
The modification time of fool.txt is 
    2015-04-01T00:00:00-0500

Touch this file.
The modification time of fool.txt is now 
    2015-04-13T14:26:26-0500

Lasso

Note this is retrieve only.

File modification date is updated on save of file. <lang Lasso>local(f) = file('input.txt') handle => { #f->close }

  1. f->modificationDate->format('%-D %r')

// result: 12/2/2010 11:04:15 PM</lang>

Lua

<lang lua>require "lfs" local attributes = lfs.attributes("input.txt") if attributes then 

   print(path .. " was last modified " .. os.date("%c", attributes.modification) .. ".")

   -- set access and modification time to now ...
   lfs.touch("input.txt")

   -- ... or set modification time to now, keep original access time
   lfs.touch("input.txt", attributes.access, os.time())

else 

   print(path .. " does not exist.")

end</lang>

Mathematica

Get file modification time: <lang Mathematica> FileDate["file","Modification"]</lang> results is returned in format: {year,month,day,hour,minute,second}. Setting file modification time: <lang Mathematica> SetFileDate["file",date,"Modification"]</lang> where date is specified as {year,month,day,hour,minute,second}.

MATLAB / Octave

<lang Matlab> f = dir('output.txt');  % struct f contains file information 

  f.date     % is string containing modification time 
  f.datenum  % numerical format (number of days) 
  datestr(f.datenum)   % is the same as f.date	
  % see also: stat, lstat </lang>

Modifying of file access time can be done through system calls:

<lang Matlab> system('touch -t 201002032359.59 output.txt'); </lang>

MAXScript

MAXScript has no method to set the mod time <lang maxscript>-- Returns a string containing the mod date for the file, e.g. "1/29/99 1:52:05 PM" getFileModDate "C:\myFile.txt"</lang>

Modula-3

<lang modula3>MODULE ModTime EXPORTS Main;

IMPORT IO, Fmt, File, FS, Date, OSError;

TYPE dateArray = ARRAY [0..5] OF TEXT;

VAR 

 file: File.Status;
 date: Date.T;

PROCEDURE DateArray(date: Date.T): dateArray = 

 BEGIN
   RETURN 
     dateArray{Fmt.Int(date.year), Fmt.Int(ORD(date.month) + 1), Fmt.Int(date.day),
               Fmt.Int(date.hour), Fmt.Int(date.minute), Fmt.Int(date.second)};
 END DateArray;

BEGIN 

 TRY
   file := FS.Status("test.txt");
   date := Date.FromTime(file.modificationTime);
   IO.Put(Fmt.FN("%s-%02s-%02s %02s:%02s:%02s", DateArray(date)));          
   IO.Put("\n");
 EXCEPT
 | OSError.E => IO.Put("Error: Failed to get file status.\n");
 END;

END ModTime.</lang>

Output:
2011-07-14 14:12:46

This program sets the modification time to any value we wish: <lang modula3>MODULE SetModTime EXPORTS Main;

IMPORT Date, FS;

<*FATAL ANY*>

VAR 

 date: Date.T;

BEGIN 

 (* Set the modification time to January 1st, 1999 *)
 date.year := 1999;
 date.month := Date.Month.Jan;
 date.day := 1;
 date.hour := 0;
 date.minute := 0;
 date.second := 0;
 date.offset := 21601;
 date.zone := "CST";

FS.SetModificationTime("test.txt", Date.ToTime(date)); END SetModTime.</lang> We can see the output with the Unix command stat

Output:
stat test.txt | grep Mod
Modify: 1999-01-01 00:00:01.000000000 -0600

NetRexx

<lang NetRexx>/* NetRexx */ options replace format comments java crossref symbols binary

runSample(arg) return

-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ method runSample(arg) public static 

 parse arg fileName
 if fileName =  then fileName = 'data/tempfile01'
 mfile = File(fileName)
 mtime = mfile.lastModified()
 dtime = Date(mtime).toString()
 say 'File' fileName 'last modified at' dtime
 say
 if mfile.setLastModified(0) then do
   dtime = Date(mfile.lastModified()).toString()
   say 'File modification time altered...'
   say 'File' fileName 'now last modified at' dtime
   say
   say 'Resetting...'
   mfile.setLastModified(mtime)
   dtime = Date(mfile.lastModified()).toString()
   say 'File' fileName 'reset to last modified at' dtime    
   end
 else do
   say 'Unable to modify time for file' fileName
   end
 return

</lang>

Output:
File data/tempfile01 last modified at Fri May 24 14:45:55 PDT 2013

File modification time altered...
File data/tempfile01 now last modified at Wed Dec 31 16:00:00 PST 1969

Resetting...
File data/tempfile01 reset to last modified at Fri May 24 14:45:55 PDT 2013

NewLISP

<lang NewLISP>;; print modification time (println (date (file-info "input.txt" 6)))

set modification time to now (Unix)

(! "touch -m input.txt")</lang>

Nim

<lang nim>import os let accTime = getLastAccessTime("filename") let modTime = getLastModificationTime("filename")

import posix var unixAccTime = Timeval(tv_sec: int(accTime)) var unixModTime = Timeval(tv_sec: int(modTime))

  1. Set the modification time

unixModTime.tv_sec = 0

var times = [unixAccTime, unixModTime] discard utimes("filename", addr(times))

  1. Set the access and modification times to the current time

discard utimes("filename", nil)</lang>

Objective-C

<lang objc>NSFileManager *fm = [NSFileManager defaultManager];

// Pre-OS X 10.5 NSLog(@"%@", [[fm fileAttributesAtPath:@"input.txt" traverseLink:YES] fileModificationDate]); [fm changeFileAttributes:[NSDictionary dictionaryWithObject:[NSDate date] forKey:NSFileModificationDate] 

                 atPath:@"input.txt"];

// OS X 10.5+ NSLog(@"%@", [[fm attributesOfItemAtPath:@"input.txt" error:NULL] fileModificationDate]); [fm setAttributes:[NSDictionary dictionaryWithObject:[NSDate date] forKey:NSFileModificationDate] 

    ofItemAtPath:@"input.txt" error:NULL];</lang>

OCaml

<lang ocaml>#load "unix.cma";; open Unix;; let mtime = (stat filename).st_mtime;; (* seconds since the epoch *)

utimes filename (stat filename).st_atime (time ());; (* keep atime unchanged 

  set mtime to current time *)</lang>

Oforth

Get only :

<lang Oforth>File new("myfile.txt") modified</lang>

OpenEdge/Progress

The file modified time can only be read.

<lang progress>FILE-INFO:FILE-NAME = 'c:/temp'. MESSAGE 

  STRING( FILE-INFO:FILE-MOD-TIME, 'HH:MM:SS' )

VIEW-AS ALERT-BOX</lang>

Oz

Getting the modification time: <lang oz>declare 

 [Path] = {Module.link ['x-oz://system/os/Path.ozf']}
 Modified = {Path.mtime "input.txt"} %% posix time

in 

 {Show {OsTime.localtime Modified}} %% human readable record</lang>

Setting the modification time is not possible, unless implemented as an extension in C or C++.

Pascal

See Delphi

Perl

Works with: Perl version 5

<lang perl>my $mtime = (stat($file))[9]; # seconds since the epoch

  1. you should use the more legible version below:

use File::stat qw(stat); my $mtime = stat($file)->mtime; # seconds since the epoch

utime(stat($file)->atime, time, $file);

  1. keep atime unchanged
  2. set mtime to current time</lang>

Perl 6

Works with: Rakudo Star version 2013-02

<lang perl6>use NativeCall;

class utimbuf is repr('CStruct') { 

   has int $.actime;
   has int $.modtime;

   submethod BUILD(:$atime, :$mtime) {
       $!actime = $atime;
       $!modtime = $mtime;
   }

}

sub sysutime(Str, utimbuf --> int) is native is symbol('utime') {*}

sub MAIN (Str $file) { 

   my $mtime = $file.IO.modified // die "Can't stat $file: $!";

   my $ubuff = utimbuf.new(:atime(time),:mtime($mtime));

   sysutime($file, $ubuff);

}</lang> Sets the last access time to now, while restoring the modification time to what it was before.

PHP

<lang php><?php $filename = 'input.txt';

$mtime = filemtime($filename); // seconds since the epoch

touch($filename, 

     time(), // set mtime to current time
     fileatime($filename)); // keep atime unchanged

?></lang>

PicoLisp

<lang PicoLisp>(let File "test.file" 

  (and
     (info File)
     (prinl (stamp (cadr @) (cddr @))) ) # Print date and time in UTC
  (call 'touch File) )                   # Set modification time to "now"</lang>
Output:
2010-02-20 15:46:37

Pop11

<lang pop11>;;; Print modification time (seconds since Epoch) sysmodtime('file') =></lang>

PowerShell

<lang powershell> $modificationTime = (Get-ChildItem file.txt).LastWriteTime Set-ItemProperty file.txt LastWriteTime (Get-Date)

$LastReadTime = (Get-ChildItem file.txt).LastAccessTime Set-ItemProperty file.txt LastAccessTime(Get-Date)

$CreationTime = (Get-ChildItem file.txt).CreationTime Set-ItemProperty file.txt CreationTime(Get-Date) </lang>

You can also use alternates to get UTC time: LastWriteTimeUtc LastAccessTimeUtc CreationTimeUtc

PureBasic

<lang PureBasic>Debug FormatDate("%yyyy/%mm/%dd", GetFileDate("file.txt",#PB_Date_Modified)) 

 SetFileDate("file.txt",#PB_Date_Modified,Date(1987, 10, 23, 06, 43, 15))

Debug FormatDate("%yyyy/%mm/%dd - %hh:%ii:%ss", GetFileDate("file.txt",#PB_Date_Modified))</lang>

Python

<lang python>import os

  1. Get modification time:

modtime = os.path.getmtime('filename')

  1. Set the access and modification times:

os.utime('path', (actime, mtime))

  1. Set just the modification time:

os.utime('path', (os.path.getatime('path'), mtime))

  1. Set the access and modification times to the current time:

os.utime('path', None)</lang>

R

See this R-devel mailing list thread for more information. <lang r># Get the value file.info(filename)$mtime

  1. To set the value, we need to rely on shell commands. The following works under windows.

shell("copy /b /v filename +,,>nul")

  1. and on Unix (untested)

shell("touch -m filename")</lang>

Racket

<lang racket>

  1. lang racket

(file-or-directory-modify-seconds "foo.rkt") </lang>

RapidQ

<lang rapidq>name$ = DIR$("input.txt", 0) PRINT "File date: "; FileRec.Date PRINT "File time: "; FileRec.Time</lang>

REALbasic

The Date object has properties which correspond to various date formats such as SQLDateTime (YYYY-MM-DD HH:MM:SS), DayOfWeek, DayOfYear, and TotalSeconds since 12:00AM, January 1, 1904, among others. <lang REALbasic> Function getModDate(f As FolderItem) As Date 

 Return f.ModificationDate

End Function</lang>


REXX

Works with: Regina REXX

The REXX language has no facility to update a file's modification time. <lang rexx>/*REXX program (Regina) to obtain/display a file's time of modification. */ parse arg $ . /*get the fileID from the CL*/ if $== then do; say "***error*** no filename was specified."; exit 13; end q=stream($, 'C', "QUERY TIMESTAMP") /*get file's mod time info. */ if q== then q="specified file doesn't exist." /*give an error indication. */ say 'For file: ' $ /*display the file ID. */ say 'timestamp of last modification: ' q /*display modification time.*/ 

                                      /*stick a fork in it,  we're all done. */</lang>

Ruby

<lang ruby>#Get modification time: modtime = File.mtime('filename')

  1. Set the access and modification times:

File.utime(actime, mtime, 'path')

  1. Set just the modification time:

File.utime(File.atime('path'), mtime, 'path')

  1. Set the access and modification times to the current time:

File.utime(nil, nil, 'path')</lang>

Run BASIC

<lang runbasic>files #f, DefaultDir$ + "\*.*" ' all files in the default directory

print "hasanswer: ";#f HASANSWER() ' does it exist print "rowcount: ";#f ROWCOUNT() ' number of files in the directory print '

  1. f DATEFORMAT("mm/dd/yy") ' set format of file date to template given
  2. f TIMEFORMAT("hh:mm:ss") ' set format of file time to template given

for i = 1 to #f rowcount() ' loop through the files if #f hasanswer() then ' or loop with while #f hasanswer() 

print "nextfile info: ";#f nextfile$("    ")   ' set the delimiter for nextfile info
print "name: ";name$                           ' file name                        
print "size: ";#f SIZE()                       ' file size
print "date: ";#f DATE$()                      ' file date
print "time: ";#f TIME$()                      ' file time
print "isdir: ";#f ISDIR()                     ' is it a directory or file

name$ = #f NAME$()
shell$("touch -t 201002032359.59 ";name$;""")  ' shell to os to set date

print

end if next</lang>

Seed7

<lang seed7>$ include "seed7_05.s7i"; 

 include "osfiles.s7i";
 include "time.s7i";

const proc: main is func 

 local
   var time: modificationTime is time.value;
 begin
   modificationTime := getMTime("data.txt");
   setMTime("data.txt", modificationTime);
 end func;</lang>

Sidef

<lang ruby>var file = File.new(__FILE__); say file.stat.mtime; # seconds since the epoch

  1. keep atime unchanged
  2. set mtime to current time

file.utime(file.stat.atime, Time.now);</lang>

Scala

Library: Scala

<lang Scala>import java.io.File import java.util.Date

object FileModificationTime extends App { 

 def test(file: File) {
   val (t, init) = (file.lastModified(),
     s"The following ${if (file.isDirectory()) "directory" else "file"} called ${file.getPath()}")

   println(init + (if (t == 0) " does not exist." else " was modified at " + new Date(t).toInstant()))
   println(init +
     (if (file.setLastModified(System.currentTimeMillis())) " was modified to current time." else " does not exist."))
   println(init +
     (if (file.setLastModified(t)) " was reset to previous time." else " does not exist."))
 }

 // main
 List(new File("output.txt"), new File("docs")).foreach(test)

}</lang>

Slate

Modifying the timestamp value is not currently a built-in feature. This code gets a raw value:

<lang slate>slate[1]> (File newNamed: 'LICENSE') fileInfo modificationTimestamp. 1240349799</lang>

Smalltalk

<lang smalltalk>|a| a := File name: 'input.txt'. (a lastModifyTime) printNl.</lang>

Standard ML

<lang sml>val mtime = OS.FileSys.modTime filename; (* returns a Time.time data structure *)

(* unfortunately it seems like you have to set modification & access times together *) OS.FileSys.setTime (filename, NONE); (* sets modification & access time to now *) (* equivalent to: *) OS.FileSys.setTime (filename, SOME (Time.now ()))</lang>

Tcl

Assuming that the variable filename holds the name of the file... <lang tcl># Get the modification time: set timestamp [file mtime $filename]

  1. Set the modification time to ‘now’:

file mtime $filename [clock seconds]</lang>

TUSCRIPT

TUSCRIPT does not allow to modify/set the timestamp of a file, but it is able to read it: <lang tuscript> $$ MODE TUSCRIPT file="rosetta.txt" ERROR/STOP OPEN (file,READ,-std-) modified=MODIFIED (file) PRINT "file ",file," last modified: ",modified </lang>

Output:
file rosetta.txt last modified: 2011-12-14 23:50:48

UNIX Shell

There are several ways to handle files' timestamps in most *nix systems. For these examples, we'll assume you need to retrieve the timestamp to a variable. These examples use stat and touch from the GNU Core Utilities, under bash, but they should work with any POSIX-compliant implementation under any sh-compatible shell.

For all of these examples, $F is a variable holding the filename to examine, while T (and $T) is the timestamp.

To get the timestamp in seconds since the epoch: <lang bash>T=`stat -c %Y $F`</lang>

To get the timestamp in human-readable format: <lang bash>T=`stat -c %y $F`</lang>

Note that the only difference between the above examples is capital Y vs lower-case y.

In the following examples, the "-c" argument to touch tells it to not create any files that don't already exist.

To set file F to time T, where T is in a human-readable format: <lang bash># Note the quotation marks -- very important! T="2000-01-01 01:02:03.040506070 -0800" touch -c -d "$T" $F</lang>

To set file F to time T, where T is in the format [[CC]YY]MMDDhhmm[.ss] (the square brackets mark optional parts): <lang bash>T=200102030405.06 touch -c -t $T $F</lang>

If the year is left out, the current year is used. If the seconds are left out, 0 (zero) is used. Leaving out the optional parts of the above results in this: <lang bash>T=02030405 touch -c -t $T $F</lang>

If no time is specified, then the timestamp is set to the current time: <lang bash>touch -c $F</lang>

There are, of course, other ways to do both tasks -- for example, one could use ls -l --time-style=full-iso and then process the resulting list with some other tool (e.g. awk or Perl).

VBScript

Works with: Windows Script Host version *

VBScript provides no way to set the last modification time. It does allow you to retrieve it, however. <lang VBScript> WScript.Echo CreateObject("Scripting.FileSystemObject").GetFile("input.txt").DateLastModified </lang>

Vedit macro language

Display file's last modification time as number of seconds since midnight. <lang vedit>Num_Type(File_Stamp_Time("input.txt"))</lang>

Displays file's last modification date and time as a string. <lang vedit>File_Stamp_String(10, "input.txt") Reg_Type(10)</lang> Vedit Macro Language has Blog in SEO no method to set the modification time

Visual Basic .NET

Platform: .NET

Works with: Visual Basic .NET version 9.0+

<lang vbnet>Dim file As New IO.FileInfo("test.txt")

'Creation Time Dim createTime = file.CreationTime file.CreationTime = createTime.AddHours(1)

'Write Time Dim writeTime = file.LastWriteTime file.LastWriteTime = writeTime.AddHours(1)

'Access Time Dim accessTime = file.LastAccessTime file.LastAccessTime = accessTime.AddHours(1)</lang>

zkl

<lang zkl>info:=File.info("input.txt"); 

 // -->T(size,last status change time,last mod time,isDir,mode), from stat(2)

info.println(); Time.Date.ctime(info[2]).println(); File.setModTime("input.txt",Time.Clock.mktime(2014,2,1,0,0,0)); File.info("input.txt")[2] : Time.Date.ctime(_).println();</lang>

Output:
L(391,1394910932,1394910932,False,33156)
Sat Mar 15 12:15:32 2014
Sat Feb 1 00:00:00 2014
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