nohup my-command

man 7 signal

       ...
   Standard signals
       Linux supports the standard signals listed below.  The second column of the table indicates which standard  (if
       any)  specified  the  signal: "P1990" indicates that the signal is described in the original POSIX.1-1990 stan‐
       dard; "P2001" indicates that the signal was added in SUSv2 and POSIX.1-2001.

       Signal      Standard   Action   Comment
       ────────────────────────────────────────────────────────────────────────
       ...
       SIGFPE       P1990      Core    Floating-point exception
       SIGHUP       P1990      Term    Hangup detected on controlling terminal
                                       or death of controlling process
       SIGILL       P1990      Core    Illegal Instruction
       ...

#include <stdio.h>

int main(){
        int i;
        while(1) { i++; }
        return 0;
}

gcc main.c
./a.out

ps -ef | grep a.out | grep -v grep

(no matching processes)

nohup ./a.out

ps -ef | grep a.out | grep -v grep

robert     29290   22470 99 15:34 pts/1    00:00:05 ./a.out

#include <signal.h>
#include <stdio.h>

static volatile int isRunning = 1;

void sighupHandler(int dummy) {
        isRunning = 0;
}

int main(){
        signal(SIGHUP, sighupHandler);
        while(isRunning) { }
        printf("SIGHUP caught, exiting...\n");
        return 0;
}

man bash

...
JOB CONTROL
       Job control refers to the ability to selectively stop (suspend) the execution of processes  and  continue  (re‐
       sume)  their  execution  at a later point.  A user typically employs this facility via an interactive interface
       supplied jointly by the operating system kernel's terminal driver and bash.
...
...
       disown [-ar] [-h] [jobspec ... | pid ... ]
              Without options, remove each jobspec from the table of active jobs.  If jobspec is not present, and nei‐
              ther the -a nor the -r option is supplied, the current job is used.  If the -h  option  is  given,  each
              jobspec  is not removed from the table, but is marked so that SIGHUP is not sent to the job if the shell
              receives a SIGHUP.  If no jobspec is supplied, the -a option means to remove or mark all  jobs;  the  -r
              option  without  a jobspec argument restricts operation to running jobs.  The return value is 0 unless a
              jobspec does not specify a valid job.
...