LastModified Timestamp of a file

•

What is DaniWeb IT Discussion Community?

You're currently browsing the C++ section within the Software Development category of DaniWeb, a massive community of 456,546 software developers, web developers, Internet marketers, and tech gurus who are all enthusiastic about making contacts, networking, and learning from each other. In fact, there are 3,377 IT professionals currently interacting right now! Registration is free, only takes a minute and lets you enjoy all of the interactive features of the site.

Join our community!

Please support our C++ advertiser: Programming Forums

Thread Tools Display Modes

Views: 3163 | Replies: 8

•

Join Date: May 2005

Location: Kolkata

Posts: 43

Reputation: amt_muk is an unknown quantity at this point

Rep Power: 4

Solved Threads: 3

amt_muk

Offline

Light Poster

LastModified Timestamp of a file

Oct 15th, 2007

Hi friends,
How can I get the time stamp of a file from C++ program.

Amit

•

Join Date: Dec 2005

Posts: 3,834

Reputation: Salem has much to be proud of

Rep Power: 23

Solved Threads: 436

Salem

Offline

banned

Re: LastModified Timestamp of a file

Oct 15th, 2007

By telling us which OS/Compiler you're working with for starters.
And you also need to make sure you have a file system which records such information.

•

Join Date: May 2005

Location: Kolkata

Posts: 43

Reputation: amt_muk is an unknown quantity at this point

Rep Power: 4

Solved Threads: 3

amt_muk

Offline

Light Poster

Re: LastModified Timestamp of a file

Oct 15th, 2007

•

Originally Posted by Salem

By telling us which OS/Compiler you're working with for starters.
And you also need to make sure you have a file system which records such information.

Actually I am working in a project which will be OS independent.
So pls give me some solution which will work on windows as well as Solaris.

•

Join Date: Aug 2005

Location: near St Louis, Missouri, USA

Posts: 11,541

Reputation: Ancient Dragon has much to be proud of

Rep Power: 40

Solved Threads: 972

Ancient Dragon Ancient Dragon is offline

Offline

Most Valuable Poster

Re: LastModified Timestamp of a file

Oct 15th, 2007

use the stat() or fstat() standard C library functions.

<<Freelance Programmer>> << Hobby Site>>
Signature links for sale. PM me for details

•

Join Date: May 2005

Location: Kolkata

Posts: 43

Reputation: amt_muk is an unknown quantity at this point

Rep Power: 4

Solved Threads: 3

amt_muk

Offline

Light Poster

Re: LastModified Timestamp of a file

Oct 15th, 2007

•

Originally Posted by Ancient Dragon

use the stat() or fstat() standard C library functions.

Thanx for your answer.
Now suppose I've a pointer of ifstream. Is there are any way to get the timestamp of that file from that pointer?

•

Join Date: Aug 2005

Location: near St Louis, Missouri, USA

Posts: 11,541

Reputation: Ancient Dragon has much to be proud of

Rep Power: 40

Solved Threads: 972

Ancient Dragon Ancient Dragon is offline

Offline

Most Valuable Poster

Re: LastModified Timestamp of a file

Oct 15th, 2007

•

Originally Posted by amt_muk

Thanx for your answer.
Now suppose I've a pointer of ifstream. Is there are any way to get the timestamp of that file from that pointer?

The stat() function does not require an open file and is compatible for every standard compliant C and C++ compiler.

Last edited by Ancient Dragon : Oct 15th, 2007 at 9:06 am.

<<Freelance Programmer>> << Hobby Site>>
Signature links for sale. PM me for details

•

Join Date: Dec 2006

Location: india

Posts: 1,085

Reputation: vijayan121 is a name known to all

Rep Power: 9

Solved Threads: 163

vijayan121 vijayan121 is offline

Offline

Veteran Poster

Re: LastModified Timestamp of a file

Oct 15th, 2007

boost::filesystem library provides portable facilities to query and manipulate paths, files, and directories.
it supports operating systems which provide either the POSIX or Windows API and is in regular use on a number of platforms (including Microsoft Windows and Sun Solaris) using a variety of compilers. programs using the library are portable, both in the syntax and the semantics of program code.

tr2 has a proposal to add a filesystem library component to the C++ Standard Library. this proposal is based on boost::filesystem. http://www.boost.org/libs/filesystem...l#Introduction

unlike most of boost, this is not a header only library. (much of the library code is platform specific. the right code is chosen based on the platform settings when building.)

here is how you could use the library to get the last modified time for a file.

 Help with Code Tags 
 c++ Syntax (Toggle Plain Text) 
#include <boost/filesystem/operations.hpp>
#include <ctime>
#include <iostream>
#include <fstream>
 
int main()
{
  boost::filesystem::path path( 
                    "/usr/local/include/boost/filesystem/operations.hpp" ) ;
  std::time_t t = boost::filesystem::last_write_time( path ) ;
  std::cout << "UTC: " << std::asctime( std::gmtime(&t) ) ;
  // note: some file system report last write time as local time, 
  // while others (eg. NTFS) report it as UTC. this can be checked 
  // by creating a new file and getting it's timestamp. eg.
  path = "/tmp/test_file" ;
  {
    std::ofstream file( path.file_string().c_str() );
    file << "test\n" ;
  }
  t = boost::filesystem::last_write_time( path ) ;
  std::cout << "just created UTC: " << std::asctime( std::gmtime(&t) ) ;
}
/**
>c++ -L/usr/local/lib -lboost_filesystem filesystem.cc && ./a.out
UTC: Tue Aug 14 13:17:48 2007
just created UTC: Mon Oct 15 15:13:39 2007
*/
#include <boost/filesystem/operations.hpp>
#include <ctime>
#include <iostream>
#include <fstream>

int main()
{
  boost::filesystem::path path( 
                    "/usr/local/include/boost/filesystem/operations.hpp" ) ;
  std::time_t t = boost::filesystem::last_write_time( path ) ;
  std::cout << "UTC: " << std::asctime( std::gmtime(&t) ) ;
  // note: some file system report last write time as local time, 
  // while others (eg. NTFS) report it as UTC. this can be checked 
  // by creating a new file and getting it's timestamp. eg.
  path = "/tmp/test_file" ;
  {
    std::ofstream file( path.file_string().c_str() );
    file << "test\n" ;
  }
  t = boost::filesystem::last_write_time( path ) ;
  std::cout << "just created UTC: " << std::asctime( std::gmtime(&t) ) ;
}
/**
>c++ -L/usr/local/lib -lboost_filesystem filesystem.cc && ./a.out
UTC: Tue Aug 14 13:17:48 2007
just created UTC: Mon Oct 15 15:13:39 2007
*/