Home/ Questions/Q 6738863
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-26T11:25:08+00:00

I am debugging a program in MacOSX, and I need that this program thinks

  • 0

I am debugging a program in MacOSX,
and I need that this program thinks we are one year later than the one given by the operating system.

I cannot change the time of the operation system, because I need to run a second program concurrently with the correct time.
I could modify the code of the first program to add one year each time it gets the time from the operation system, but the code is too big to do that; I prefer not to use this solution.

I heard once that there is a command in Unix to run a program with a fake/mocked time.
Do you know about it?

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    I haven’t tried it, but libfaketime claims to do what you need.

    Quoted from the website:

    As an example, we want the “date” command to report our faked time. To do so, we could use the following command line:

    user@host> date
Tue Nov 23 12:01:05 CEST 2007

user@host> LD_PRELOAD=/usr/local/lib/libfaketime.so.1 FAKETIME="-15d" date
Mon Nov  8 12:01:12 CEST 2007

    Assuming the lib works as advertised, you can trick your program into thinking it was running a year ahead using:

    LD_PRELOAD=/usr/local/lib/libfaketime.so.1 FAKETIME="+1y" ./your_program
    • 0