Function Override 1

[naveenprakashj]

Hi all,

I want to redeclare/redefine a few of the library functions. For. Ex. localtime() of time.h

I have heaps of code wherein localtime() is used. I want to write a wrapper function for localtime as part of the local library which will override the standard localtime(). I dont want to visit each sourcecode and knock off the time.h declaration.

I would like to how know how this can be achieved. If you are not clear with my question, pls. let me know.

Thanks for your time.

 

[Nosferatu]

Well, try using the old #define trick...

Just replace the localtime definition with your own:
#define localtime my_localtime.

You can safely use localtime throughout your code, but the calls will go to your function. [red]Nosferatu[/red]
We are what we eat...
There's no such thing as free meal...
once stated: methane@personal.ro

 

[naveenprakashj]

Hey thnx for the solution. But the problem is that I want to use the localtime() within my_localtime again!!!
This will result in an infintie recursive call to my_localtime and I'll b not able to invoke the actual localtime()

Can u pls. come up with any other ideas??

Any feedback is well appreciated.

 

[naveenprakashj]

Hey nosferatu!!

I kinda liked ur idea and have implemented it. But with a bit of re-engineering!!

Thankx for ur suggestion. It has been very helpful.

 

[lordblood]

Going with the #define idea .... I didnt test this completely but worked for my small example. This was done on a solaris machine. I'm sure someone probably has a better way of doing this but I thought I'd give ya something to think about. ;-)

you can try (example)

#include <stdio.h>
#include <time.h>

#define localtime(a) mylocaltime(a)

main()
{
time_t ts;
stuct tm *gmt;

struct tm * mylocaltime();

time(&ts);
gmt = localtime(&ts);

printf(&quot;Year is: %d\n&quot;, gmt->tm_year + 1900);

return 0;
}

struct tm * mylocaltime(time_t *ts)
{
#undef localtime(a)

struct tm *gmt;

gmt = localtime(ts);

#define localtime(a) mylocaltime(a)

return gmt;
}