How to time how long a program takes to run?

advancedk · 08-18-2008, 06:13 PM

Hi

I have written a C program that is supposed to run in under 2 seconds. Is there a function in C that lets me time how long it takes to run the program?

Thanks

mike_g · 08-18-2008, 06:26 PM

I often used clock() in time.h to get the time in millisecs. Only problem with that is that returns the number of clock cycles on linux so you have to divide it by CLOCKS_PER_SEC according to the manpage. Anyway its simple to use:

Code:

start_time = clock()
// do stuff
end_time = clock()
seconds_elapsed = (end_time - start_time) / 1000;

Alternatively theres gettimeofday(), which is more precise.

zacs7 · 08-18-2008, 07:50 PM

On Linux I'd be using time anyway.

Code:

[ ~]$ time ./myprog

real	0m3.855s
user	0m0.057s
sys	0m0.297s

Of course that method also counts how long your program takes to start.

08-18-2008, 06:13 PM	#1
advancedk Registered User Join Date: Jul 2008 Posts: 15	How to time how long a program takes to run? Hi I have written a C program that is supposed to run in under 2 seconds. Is there a function in C that lets me time how long it takes to run the program? Thanks
advancedk is offline

08-18-2008, 06:26 PM	#2
mike_g Wheres the lesbians? Join Date: Oct 2006 Location: UK Posts: 1,219	I often used clock() in time.h to get the time in millisecs. Only problem with that is that returns the number of clock cycles on linux so you have to divide it by CLOCKS_PER_SEC according to the manpage. Anyway its simple to use: Code: start_time = clock() // do stuff end_time = clock() seconds_elapsed = (end_time - start_time) / 1000; Alternatively theres gettimeofday(), which is more precise. __________________ Senior highbrow doctor of authority.
mike_g is offline

08-18-2008, 07:50 PM	#3
zacs7 Woof, woof! Join Date: Mar 2007 Location: Australia Posts: 3,139	On Linux I'd be using time anyway. Code: [ ~]$ time ./myprog real 0m3.855s user 0m0.057s sys 0m0.297s Of course that method also counts how long your program takes to start. __________________ "I.T. gets the chicky-babes" - M. Kelly bakefile \| vim
zacs7 is offline

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Inserting a swf file in a windows application	face_master	Windows Programming	12	05-03-2009 11:29 AM
can't get this program to run correctly	Amyaayaa	C++ Programming	3	02-05-2008 04:16 PM
Merge and Heap..which is really faster	silicon	C++ Programming	2	05-10-2005 04:06 PM
Program in linux to do LOTS of math (takes long time to complete)	Leeman_s	Linux Programming	3	03-21-2004 06:02 PM
What's the code for a program to run in Task manager, under the processes tab	newbie1	Windows Programming	5	04-17-2003 07:07 AM