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   comp.lang.c      Meh, in C you gotta define EVERYTHING      243,242 messages   

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   Message 242,797 of 243,242   
   Lew Pitcher to Michael S   
   Re: printf and time_t   
   05 Jan 26 16:23:09   
   
   From: lew.pitcher@digitalfreehold.ca   
      
   On Mon, 05 Jan 2026 10:51:38 +0200, Michael S wrote:   
      
   > On Mon, 5 Jan 2026 00:17:07 -0800   
   > Andrey Tarasevich  wrote:   
   >   
   >> On Sun 1/4/2026 11:19 PM, Kenny McCormack wrote:   
   >> > The question is: How can you reliably printf() a time_t value?   
   >> > What conversion spec should you use?   
   >>   
   >> You can't. As far as the language is concerned, `time_t` is intended   
   >> to be an opaque type. It has to be a real type, so it is either an   
   >> integer of a plain floating-point type. But other than that nothing   
   >> is known about it. There's really no point in printing it.   
   >>   
   >> If you still want to, you can do it in some implementation-specific   
   >> way. Which still immediately means that you can't do it "reliably",   
   >> if I understand what you mean correctly.   
   >>   
   >   
   > I can't think about situation in which casting time_t value to 'long   
   > long' can go wrong.   
      
   As Andrey pointed out, time_t can resolve to a floatingpoint type,   
   so, "long long" would go wrong if the implementation typedefs it to   
    float, or   
    double, or   
    long double.   
      
   --   
   Lew Pitcher   
   "In Skills We Trust"   
   Not LLM output - I'm just like this.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)   

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