Get the boot time in objective c

Question

how can i get the boot time of ios in objective c ?

Is there a way to get it?

Try using [`clock()`](http://www.cplusplus.com/reference/clibrary/ctime/clock/). I am unsure what it returns in iOS, but it's part of the standard library, so it has a reasonable chance of doing what it shouold. — Sergey Kalinichenko, Apr 26 '12 at 09:52
@tipycalFlow no, i meant the ios launch time (the operating system). thanks — Y2theZ, Apr 26 '12 at 09:56
you mean something like /proc/uptime in linux? http://stackoverflow.com/q/4972651/550177 — Felix, Apr 26 '12 at 10:19
@phix23 yes that's what I'm looking for but in IOS not linux. thanks — Y2theZ, Apr 26 '12 at 10:29

score 12 · Accepted Answer · edited Apr 26 '12 at 12:54

12

Don't know if this will work in iOS, but in OS X (which is essentially the same OS) you would use sysctl(). This is how the OS X Unix utility uptime does it. Source code is available - search for "boottime".

#include <sys/types.h>
#include <sys/sysctl.h>  

// ....  

#define MIB_SIZE 2  

int mib[MIB_SIZE];
size_t size;
struct timeval  boottime;

mib[0] = CTL_KERN;
mib[1] = KERN_BOOTTIME;
size = sizeof(boottime);
if (sysctl(mib, MIB_SIZE, &boottime, &size, NULL, 0) != -1)
{
    // successful call
    NSDate* bootDate = [NSDate dateWithTimeIntervalSince1970:boottime.tv_sec];
}

The restricted nature of programming in the iOS sandboxed environment might make it not work, I don't know, I haven't tried it.

edited Apr 26 '12 at 12:54

Felix

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answered Apr 26 '12 at 10:37

JeremyP

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1

There are apps in the App Store that are using sysctl functionality. Doesn't necessarily mean this would be allowed though. – mttrb Apr 26 '12 at 10:56
2

seems to work, I edited the answer to show how to get it as NSDate – Felix Apr 26 '12 at 12:55
2

It is absolutely allowed on the app store – Dickey Singh Jun 20 '14 at 17:24

score 1 · Answer 2 · answered Jan 13 '20 at 20:02

I took JeremyP's answer, gave the result the full microsecond precision, clarified the names of local variables, improved the order, and put it into a method:

#include <sys/types.h>
#include <sys/sysctl.h>  

// ....  

+ (nullable NSDate *)bootDate
{
    // nameIntArray and nameIntArrayLen
    int nameIntArrayLen = 2;
    int nameIntArray[nameIntArrayLen];
    nameIntArray[0] = CTL_KERN;
    nameIntArray[1] = KERN_BOOTTIME;

    // boot_timeval
    struct timeval boot_timeval;
    size_t boot_timeval_size = sizeof(boot_timeval);
    if (sysctl(nameIntArray, nameIntArrayLen, &boot_timeval, &boot_timeval_size, NULL, 0) == -1)
    {
        return nil;
    }

    // bootSince1970TimeInterval
    NSTimeInterval bootSince1970TimeInterval = (NSTimeInterval)boot_timeval.tv_sec + ((NSTimeInterval)boot_timeval.tv_usec / 1000000);

    // return
    return [NSDate dateWithTimeIntervalSince1970:bootSince1970TimeInterval];
}

Get the boot time in objective c

2 Answers2

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