execute bash?

[Puming via Digitalmars-d-learn]

On Friday, 8 April 2016 at 13:25:37 UTC, Adam D. Ruppe wrote:
> On Friday, 8 April 2016 at 13:23:10 UTC, Adam D. Ruppe wrote:
>> Odds are it is that there's terminal output for the background 
>> process
>
> NOT a character btw, just any output, then the OS puts you on 
> hold so it can do its thing.
>
> To catch a signal, it is just like in C 
> http://stackoverflow.com/a/35687472/1457000
>
> simplest case:
>
> import core.stdc.signal;
> signal(SIGTTOU, SIG_IGN); // ignore the output thing
>
>
> and see what happens next

Found another problem: I can't even catch SIGINT in a simple 
program:

import std.stdio;
import std.process;
import core.stdc.signal;
import core.thread;
import std.datetime;


extern(C) void sig_hand(int signal) nothrow @nogc @system {
     import core.stdc.stdio: printf;
     printf("signal %d catched!\n", signal);
}

void main() {
     if (signal(SIGINT, &sig_hand) == SIG_ERR) {
         writeln("can't catch SIGINT");
     }

     string line;
     write("> ");
     while(1) {
         Thread.sleep(1.seconds);
     }
     /*
     while ((line = readln()) != null) {
         writeln("you said:", line);
         write("> ");
     }
     */
}

When using while with Thread.sleep, Ctrl+C will show

signal 2 catched!

then the program is gone, but its process is still found with `ps 
-ef`, which I have to kill manually.

In the c version as shown here 
<http://www.thegeekstuff.com/2012/03/catch-signals-sample-c-code/>, the loop will go on and you can press multiple Ctrl-C.

The D version behavior is strange.

When Using while with readln, after hitting Ctrl-C, the next 
readln will throw exception:

std.stdio.StdioException at std/stdio.d(3977): Input/output error
----------------
??:? void std.stdio.StdioException.opCall() [0x498531]
??:? ulong 
std.stdio.readlnImpl(shared(core.stdc.stdio._IO_FILE)*, ref 
char[], dchar, std.stdio.File.Orientation) [0x498676]
/usr/include/dmd/phobos/std/stdio.d:1565 ulong 
std.stdio.File.readln!(char).readln(ref char[], dchar) [0x486fac]
/usr/include/dmd/phobos/std/stdio.d:1426 immutable(char)[] 
std.stdio.File.readln!(immutable(char)[]).readln(dchar) [0x486eb1]
/usr/include/dmd/phobos/std/stdio.d:3385 immutable(char)[] 
std.stdio.readln!(immutable(char)[]).readln(dchar) [0x486e3b]
source/app.d:25 _Dmain [0x48677e]
??:? 
_D2rt6dmain211_d_run_mainUiPPaPUAAaZiZ6runAllMFZ9__lambda1MFZv 
[0x48ad2a]
??:? void rt.dmain2._d_run_main(int, char**, extern (C) int 
function(char[][])*).tryExec(scope void delegate()) [0x48ac74]
??:? void rt.dmain2._d_run_main(int, char**, extern (C) int 
function(char[][])*).runAll() [0x48ace6]
??:? void rt.dmain2._d_run_main(int, char**, extern (C) int 
function(char[][])*).tryExec(scope void delegate()) [0x48ac74]
??:? _d_run_main [0x48abe5]
??:? main [0x487b0b]
??:? __libc_start_main [0xc7628ec4]