SIGCONT occurs after a SIGTERM
Sean Sheridan Coleman X5672
coleman at cam.nist.gov
Tue Feb 12 04:06:07 AEST 1991
Please explain to me why a SIGCONT is sent to a process after
SIGTERM is sent to my process. It doesn't compute because TERM
means to terminate the the process. I catch SIGCONT because I
do some reconnecting for serial drivers after my process is
stopped from a cntl-Z. Below is a piece of the code and a
some output from the program.
Here I stop the program with a ^Z and restart using fg %1.
SIGCONT is sent in this situation correctly.
<deputy /home/central/coleman/real_prog/net.dir/net_log> % net l logfile
^Z Signal caught is 18
Stopped (signal)
<deputy /home/central/coleman/real_prog/net.dir/net_log> % jobs
[1] + Stopped (signal) net l logfile
<deputy /home/central/coleman/real_prog/net.dir/net_log> % fg %1
net l logfile
Signal caught is 19
^C Signal caught is 2
>From another window, I used kill -TERM to kill this process.
SIGTERM is received first but then SIGCONT is sent for no known
reason.
<deputy /home/central/coleman/real_prog/net.dir/net_log> % !ne
net l logfile
Signal caught is 15
Signal caught is 19
No devices are available to use for logging
Here is the signal handler:
Note: device,device_file and device_name are global
sig_handler(sig)
int sig;
{
extern int device;
extern FILE *device_file;
extern char *device_name;
char *strip_add_dev_name();
printf(" Signal caught is %d\n",sig);
switch(sig)
{
case SIGINT:
case SIGTERM:
unlock_dev(strip_add_dev_name(ttyname(device),0));
exit(1);
case SIGTSTP:
unlock_dev(strip_add_dev_name(ttyname(device),0));
close(device);
kill(0,SIGSTOP);
break;
case SIGCONT:
if(device_file != NULL)
{
rewind(device_file);
device = get_device(device_file);
}
else
{
if((device = chk_device(device_name)) < 0)
{
printf("No devices are available to use for logging\n");
exit(1);
}
}
default:
break;
}
}
Thanks
Sean Coleman
coleman at bldrdoc.gov
NIST
Boulder, CO
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