Couple of Ubuntu a terminal refresh a matter of time-CodePudding

Individual was in a Unix, Linux programming practice book, do here didn't force, I try to use the stat function to read/dev/PTS/19 command shown in the terminal name (ps), and obtain atim and mtim, and/dev/the atim tty7 and mtim,

My idea is that
Set a itimer, first read/dev/PTS/19 atime, read your program I set the maximum time taccess, set the countdown to taccess seconds of itimer, and after a timeout, triggering a SIG_ALRM signal, awaken the signal service program, atime reading again, if there is no change, program exits, if have change, return the service procedure,
Ps: this time really not enough accurate
But I try to service program in the timer to run only after the print tty atime, found tty atime won't have change, even if I won't refresh, type the command in bash in distress, is the place where I read it? Few words said, the first code,

 
#include  
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#include  
Void sendKill (int s); 
Int set_ticker (int n_msecs); 

Int Tcount=0; 
Int pid=0; 
Int Taccess=0; 
Int times=0; 

Struct stat file_info; 

//set a timer, the when it drained, the program will send a sigkill signal to the pid you want 
Int main (int ac, char * * av) 
{


Tcount=atoi (av [1]); 
Pid=atoi (av [2]); 



Printf (" \ t Tcount: % d ", Tcount); 
Printf (" pid: % d \ n ", pid); 

If (stat ("/dev/PTS/19 ", & amp; File_info)) 
Perror (" stat "); 

Taccess=file_info. St_atim. Tv_nsec; 

//set itimer 
Set_ticker (5000); 
Alarm (5); 


Signal (SIGALRM sendKill); 


Printf (" Taccess first % d \ n ", Taccess); 

While (1) {
Pause (); 
} 


} 
Void sendKill (int s) 
{
Signal (SIGALRM sendKill); 

Int TMP. 
If (stat ("/dev/PTS/19 ", & amp; File_info)) 
Perror (" stat "); 
TMP=file_info. St_mtim. Tv_nsec; 
Printf (" \ n \ n % d ", TMP); 


Times++; 
If (times & gt; 3) 
exit(1); 
}

CodePudding user response:

There is still no change even if I refresh the terminal time