@@CodeVault Hi I just watched the video. I was more looking for an example where you would do it manually instead of using the built-in shell functionality. one where you would have a signal handler that catches crtl z and send the process a SIGTSTP. and then when we want to continue we can type like "fg" and we manually send a SIGCONT.
Hi, I would like to know why do you refer "pid" in your else statements as child process pid. Won't code under else statements be executed only for parent process and pid will be equal to some number other than zero? So does that mean the function kill() takes parent process pid instead of the child's?
Because that what fork() returns. So: int pid = fork(); pid will be 0 in the child process pid will be the child's process id in the parent process Basically fork never returns the parent's process id. It only returns the process ID of the process it created, and that ID is returned only in the parent's process execution line
question: when you fork it, and then you have 2 pids as you have 2 processes: why is the child NOT printing at least once? the line: if (pid ==0) - which pid will be first? because if the first one is pid = 0 then the process should print once at least before program goes to "else" where it sends STOP. Or another way: with such code, is it guaranteed that it will NEVER print because parent sends STOP before even first print occured in child process?
The order of execution is basically undefined. Although there is probably a higher chance that the parent executes further ahead than the child due to the child process having to initialize things internally
How can you be sure that the father process will be executed first and thus will send SIGSTOP before the child prints? Isn't is possible that the child executes first and prints at least one time before receiving the signal?
You are correct. We're not 100% sure the child process executes before the parent process. To do that, we could try using a pipe or a synchronization object to make sure they always work that way
actually the signals.h header file is marked as not found fatal error: signals.h: Aucun fichier ou dossier de ce type can you please provide some solutions
Thank you so much for this video. You just saved a college student. I have a question. What if I dont want to use scanf to get the user input like say when the user enters a value in the terminal like a signal, how do I approach that
I know Im asking the wrong place but does anyone know a method to get back into an instagram account? I was dumb lost the login password. I love any tips you can give me
@Jeremiah Deangelo Thanks so much for your reply. I found the site thru google and Im in the hacking process atm. Looks like it's gonna take quite some time so I will reply here later with my results.
@@CodeVault #include #include #include #include #include int main(){ int x,i=-1; x=fork(); switch (x) { case -1: printf("ERROR");break; case 0: while(i
You are solving lots of my problems in C language and understanding operating system concepts.Thank you so much.God bless you..
Thank you ,this is exactly what i need for my OS homework and teachers wont tell it at class
These videos are so good. Thank you.
Can you show us on for SIGTSTP and SIGCONT. Thanks Love the video btw . very well explained
There's this video related to SIGTSTP: code-vault.net/lesson/eytyugwr7b:1603732432740
@@CodeVault Hi I just watched the video. I was more looking for an example where you would do it manually instead of using the built-in shell functionality. one where you would have a signal handler that catches crtl z and send the process a SIGTSTP. and then when we want to continue we can type like "fg" and we manually send a SIGCONT.
best content bro, thank you. amazing guidance
Hi, I would like to know why do you refer "pid" in your else statements as child process pid. Won't code under else statements be executed only for parent process and pid will be equal to some number other than zero? So does that mean the function kill() takes parent process pid instead of the child's?
Because that what fork() returns. So:
int pid = fork();
pid will be 0 in the child process
pid will be the child's process id in the parent process
Basically fork never returns the parent's process id. It only returns the process ID of the process it created, and that ID is returned only in the parent's process execution line
@@CodeVault This was very clear. Thank you
much appreciated you for your efforts sir
You are an amazing person, thanks a lot!
Mr Meeseeks simulation
Hahaha, Rick and Morty, love that show
question: when you fork it, and then you have 2 pids as you have 2 processes: why is the child NOT printing at least once? the line: if (pid ==0) - which pid will be first? because if the first one is pid = 0 then the process should print once at least before program goes to "else" where it sends STOP. Or another way: with such code, is it guaranteed that it will NEVER print because parent sends STOP before even first print occured in child process?
The order of execution is basically undefined. Although there is probably a higher chance that the parent executes further ahead than the child due to the child process having to initialize things internally
Very clear explanation!
How can you be sure that the father process will be executed first and thus will send SIGSTOP before the child prints? Isn't is possible that the child executes first and prints at least one time before receiving the signal?
You are correct. We're not 100% sure the child process executes before the parent process. To do that, we could try using a pipe or a synchronization object to make sure they always work that way
actually the signals.h header file is marked as not found
fatal error: signals.h: Aucun fichier ou dossier de ce type
can you please provide some solutions
Why the parent process is executing first each time. Isn't it be a decision by OS.
I guess it's just a matter of probability. The parent process executing first has a much higher chance than the child process (although it's not 100%)
good explanation thanks a lot !!
Thank you so much for this video. You just saved a college student. I have a question. What if I dont want to use scanf to get the user input like say when the user enters a value in the terminal like a signal, how do I approach that
You mean how do you catch signals from the terminal sent by the user?
@@CodeVault yeah like the esc signal to exit a program
I know Im asking the wrong place but does anyone know a method to get back into an instagram account?
I was dumb lost the login password. I love any tips you can give me
@Grant Owen instablaster ;)
@Jeremiah Deangelo Thanks so much for your reply. I found the site thru google and Im in the hacking process atm.
Looks like it's gonna take quite some time so I will reply here later with my results.
can you include the sessions for the message queue, shared memory and sockets.Thanks for your sessions.Those are really helpful..
They are on the TODO list. After threads, will look into those as well. Thanks for the suggestion!
Thanks!
very helpful thanks
Voila! merci pour le tuto
How can I do it with system (..)
Like system(kill -STOP ??)
+How can I know the pid of the child process to stop it...
The pic? You mean the process id? You get it as a return value of fork()
@@CodeVault
#include
#include
#include
#include
#include
int main(){
int x,i=-1;
x=fork();
switch (x)
{
case -1: printf("ERROR");break;
case 0: while(i
This is an infinite loop. Either have it change the value of i inside of it or use a different condition
while(i
Can you explain the example of int pthread_kill()
Sure I will look into it