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Old 03-18-2023, 08:22 AM   #1
Xeratul
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How to reboot Linux using a C programming language code ?


Hello,

Do you have maybe a reboot.c to reboot linux, using C?

gcc or clang.

Kind regards
 
Old 03-18-2023, 08:23 AM   #2
Xeratul
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https://github.com/torvalds/linux/bl...ernel/reboot.c <--- this is NOT LIGHT
 
Old 03-18-2023, 08:24 AM   #3
Xeratul
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Quote:
For a large number of reasons, it is better to power off the machine using e.g.

execl("/bin/shutdown", "shutdown", "-P", "now", (char *)0);
or reboot using

execl("/bin/shutdown", "shutdown", "-r", "now", (char *)0);
is really a highly crap answer
 
1 members found this post helpful.
Old 03-18-2023, 08:50 AM   #4
teckk
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Code:
man execl
mytest.c
Code:
#include <unistd.h>

int main()
{
    execl("/bin/ls", "ls", "-a", (char*) NULL);
    return 0;
}

//gcc mytest.c -o mytest
 
Old 03-18-2023, 11:05 AM   #5
dugan
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This is closer to what you're looking for:

https://kernel.googlesource.com/pub/...ils/shutdown.c
 
Old 03-18-2023, 12:32 PM   #6
onebuck
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Moderator Response

Moved: This thread is more suitable in <Programming> and has been moved accordingly to help your thread/question get the exposure it deserves.
 
Old 03-18-2023, 02:33 PM   #7
Xeratul
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Quote:
Originally Posted by teckk View Post
Code:
man execl
mytest.c
Code:
#include <unistd.h>

int main()
{
    execl("/bin/ls", "ls", "-a", (char*) NULL);
    return 0;
}

//gcc mytest.c -o mytest
it sucks totally, i.e. system( "/sbin/reboot" ) or execl isnt C programming...
 
Old 03-20-2023, 01:56 AM   #8
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https://man7.org/linux/man-pages/man2/reboot.2.html
 
2 members found this post helpful.
Old 03-20-2023, 05:37 AM   #9
Xeratul
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Quote:
Originally Posted by teckk View Post
Code:
man execl
mytest.c
Code:
#include <unistd.h>

int main()
{
    execl("/bin/ls", "ls", "-a", (char*) NULL);
    return 0;
}

//gcc mytest.c -o mytest
this above code is so much ugly man.
 
Old 03-20-2023, 05:39 AM   #10
Xeratul
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Quote:
#include <unistd.h>
#include <sys/reboot.h>
int main() {
reboot(RB_POWER_OFF);
}


Some attempts... however it will power off

cc -static reboot.c -o myreboot
 
Old 03-20-2023, 06:16 AM   #11
NevemTeve
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BTW, what is the actual problem to solve?
 
Old 03-20-2023, 11:42 PM   #12
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Did you try RB_AUTOBOOT ?
 
Old 04-26-2023, 03:13 AM   #13
gulshan212
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Hello this is Gulshan Negi
Well, the reboot function provided by the Linux system call interface can be used to reboot a Linux system using the C programming language.
Example:
#include <unistd.h>
#include <sys/reboot.h>

int main() {
int result = reboot(RB_AUTOBOOT); // initiate a system reboot

if (result == -1) {
perror("Reboot failed");
return 1;
} else {
printf("Rebooting...\n");
return 0;
}
}

I hope it will help you.
Thanks
 
Old 04-27-2023, 08:54 AM   #14
sundialsvcs
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As others have said, usually the best approach is to "exec" the reboot command. (Remember to handle the case where the user doesn't have the privilege to run it.)

And, "this being open-source Linux," you can examine the actual source code of this command to see precisely how it works.
 
Old 04-30-2023, 07:10 PM   #15
Xeratul
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Quote:
Originally Posted by gulshan212 View Post
Hello this is Gulshan Negi
Well, the reboot function provided by the Linux system call interface can be used to reboot a Linux system using the C programming language.
Example:
#include <unistd.h>
#include <sys/reboot.h>

int main() {
int result = reboot(RB_AUTOBOOT); // initiate a system reboot

if (result == -1) {
perror("Reboot failed");
return 1;
} else {
printf("Rebooting...\n");
return 0;
}
}

I hope it will help you.
Thanks


Could it be done without reboot.h ?

#include <sys/reboot.h>

look shutdown.c does not have reboot.h

#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <utmp.h>
#include <time.h>
#include <string.h>
#include <ctype.h>
#include <signal.h>
#include <sys/param.h>
#include <termios.h>
#include <mntent.h>
#include <sys/mount.h>
#include <sys/wait.h>
#include <syslog.h>
#include <sys/resource.h>
#include "pathnames.h"

Last edited by Xeratul; 04-30-2023 at 07:11 PM.
 
  


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