Re: [hackers] setsid: add optional -f to force fork()

2020-07-25 Thread Michael Forney 
On 2020-07-14, Hiltjo Posthuma  wrote:
> The below patch adds an -f flag to force fork(2)ing and creating a new
> process.

Thanks, I applied the patch.

Though I wonder, is Linux the only operating system that typically has
setsid(1)? It doesn't look like it is available on BSDs. It's such a
small tool and it can be implemented portably so I guess it's fine as
a part of sbase, but I wonder if there is some other tool with similar
functionality on other systems.

Re: [hackers] setsid: add optional -f to force fork()

2020-07-25 Thread Hiltjo Posthuma 
On Tue, Jul 14, 2020 at 10:15:43AM +0200, Hiltjo Posthuma wrote:
> Hi,
> 
> The below patch adds an -f flag to force fork(2)ing and creating a new 
> process.
> 
> 
> From a75ef384c11b64732dd6a3adc9249ba6beb8a67e Mon Sep 17 00:00:00 2001
> From: Hiltjo Posthuma 
> Date: Tue, 14 Jul 2020 10:11:43 +0200
> Subject: [PATCH] setsid: add optional -f to force fork()
> 
> ---
>  setsid.1 | 3 ++-
>  setsid.c | 9 +++--
>  2 files changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/setsid.1 b/setsid.1
> index d43bcfc..4df6439 100644
> --- a/setsid.1
> +++ b/setsid.1
> @@ -1,4 +1,4 @@
> -.Dd 2015-10-08
> +.Dd 2020-07-14
>  .Dt SETSID 1
>  .Os sbase
>  .Sh NAME
> @@ -6,6 +6,7 @@
>  .Nd run a command in a new session
>  .Sh SYNOPSIS
>  .Nm
> +.Op Fl f
>  .Ar cmd
>  .Op Ar arg ...
>  .Sh DESCRIPTION
> diff --git a/setsid.c b/setsid.c
> index 28d3442..3355b40 100644
> --- a/setsid.c
> +++ b/setsid.c
> @@ -4,10 +4,12 @@
>  
>  #include "util.h"
>  
> +static int fflag = 0;
> +
>  static void
>  usage(void)
>  {
> - eprintf("usage: %s cmd [arg ...]\n", argv0);
> + eprintf("usage: %s cmd [-f] [arg ...]\n", argv0);
>  }
>  
>  int
> @@ -16,6 +18,9 @@ main(int argc, char *argv[])
>   int savederrno;
>  
>   ARGBEGIN {
> + case 'f':
> + fflag = 1;
> + break;
>   default:
>   usage();
>   } ARGEND
> @@ -23,7 +28,7 @@ main(int argc, char *argv[])
>   if (!argc)
>   usage();
>  
> - if (getpgrp() == getpid()) {
> + if (fflag || getpgrp() == getpid()) {
>   switch (fork()) {
>   case -1:
>   eprintf("fork:");
> -- 
> 2.27.0
> 
> 
> -- 
> Kind regards,
> Hiltjo
> 

Bump, any response/feedback to get this in master?

-- 
Kind regards,
Hiltjo

Re: [hackers] setsid: add optional -f to force fork()

2020-07-14 Thread Hiltjo Posthuma 
On Tue, Jul 14, 2020 at 12:15:20PM +0200, Mattias Andrée wrote:
> Hi,
> 
> Is there any reason you would want to force it?
> 
> 

Yes, when getpgrp() != getpid().

I use this in my plumb script for my news program to setsid -f and open a link
my browser. Using the setsid -f option the browser is not closed when I close
my news program (due to it being in the same process group).

The -f option exists already in the util-linux(-ng) implementation:
https://www.man7.org/linux/man-pages/man1/setsid.1.html
https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/tree/sys-utils/setsid.c#n96

> Regards,
> Mattias Andrée
> 
> 
> On Tue, 14 Jul 2020 10:15:43 +0200
> Hiltjo Posthuma  wrote:
> 
> > Hi,
> > 
> > The below patch adds an -f flag to force fork(2)ing and creating a new 
> > process.
> > 
> > 
> > From a75ef384c11b64732dd6a3adc9249ba6beb8a67e Mon Sep 17 00:00:00 2001
> > From: Hiltjo Posthuma 
> > Date: Tue, 14 Jul 2020 10:11:43 +0200
> > Subject: [PATCH] setsid: add optional -f to force fork()
> > 
> > ---
> >  setsid.1 | 3 ++-
> >  setsid.c | 9 +++--
> >  2 files changed, 9 insertions(+), 3 deletions(-)
> > 
> > diff --git a/setsid.1 b/setsid.1
> > index d43bcfc..4df6439 100644
> > --- a/setsid.1
> > +++ b/setsid.1
> > @@ -1,4 +1,4 @@
> > -.Dd 2015-10-08
> > +.Dd 2020-07-14
> >  .Dt SETSID 1
> >  .Os sbase
> >  .Sh NAME
> > @@ -6,6 +6,7 @@
> >  .Nd run a command in a new session
> >  .Sh SYNOPSIS
> >  .Nm
> > +.Op Fl f
> >  .Ar cmd
> >  .Op Ar arg ...
> >  .Sh DESCRIPTION
> > diff --git a/setsid.c b/setsid.c
> > index 28d3442..3355b40 100644
> > --- a/setsid.c
> > +++ b/setsid.c
> > @@ -4,10 +4,12 @@
> >  
> >  #include "util.h"
> >  
> > +static int fflag = 0;
> > +
> >  static void
> >  usage(void)
> >  {
> > -   eprintf("usage: %s cmd [arg ...]\n", argv0);
> > +   eprintf("usage: %s cmd [-f] [arg ...]\n", argv0);
> >  }
> >  
> >  int
> > @@ -16,6 +18,9 @@ main(int argc, char *argv[])
> > int savederrno;
> >  
> > ARGBEGIN {
> > +   case 'f':
> > +   fflag = 1;
> > +   break;
> > default:
> > usage();
> > } ARGEND
> > @@ -23,7 +28,7 @@ main(int argc, char *argv[])
> > if (!argc)
> > usage();
> >  
> > -   if (getpgrp() == getpid()) {
> > +   if (fflag || getpgrp() == getpid()) {
> > switch (fork()) {
> > case -1:
> > eprintf("fork:");
> 
> 

-- 
Kind regards,
Hiltjo

Re: [hackers] setsid: add optional -f to force fork()

2020-07-14 Thread Mattias Andrée 
Hi,

Is there any reason you would want to force it?


Regards,
Mattias Andrée


On Tue, 14 Jul 2020 10:15:43 +0200
Hiltjo Posthuma  wrote:

> Hi,
> 
> The below patch adds an -f flag to force fork(2)ing and creating a new 
> process.
> 
> 
> From a75ef384c11b64732dd6a3adc9249ba6beb8a67e Mon Sep 17 00:00:00 2001
> From: Hiltjo Posthuma 
> Date: Tue, 14 Jul 2020 10:11:43 +0200
> Subject: [PATCH] setsid: add optional -f to force fork()
> 
> ---
>  setsid.1 | 3 ++-
>  setsid.c | 9 +++--
>  2 files changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/setsid.1 b/setsid.1
> index d43bcfc..4df6439 100644
> --- a/setsid.1
> +++ b/setsid.1
> @@ -1,4 +1,4 @@
> -.Dd 2015-10-08
> +.Dd 2020-07-14
>  .Dt SETSID 1
>  .Os sbase
>  .Sh NAME
> @@ -6,6 +6,7 @@
>  .Nd run a command in a new session
>  .Sh SYNOPSIS
>  .Nm
> +.Op Fl f
>  .Ar cmd
>  .Op Ar arg ...
>  .Sh DESCRIPTION
> diff --git a/setsid.c b/setsid.c
> index 28d3442..3355b40 100644
> --- a/setsid.c
> +++ b/setsid.c
> @@ -4,10 +4,12 @@
>  
>  #include "util.h"
>  
> +static int fflag = 0;
> +
>  static void
>  usage(void)
>  {
> - eprintf("usage: %s cmd [arg ...]\n", argv0);
> + eprintf("usage: %s cmd [-f] [arg ...]\n", argv0);
>  }
>  
>  int
> @@ -16,6 +18,9 @@ main(int argc, char *argv[])
>   int savederrno;
>  
>   ARGBEGIN {
> + case 'f':
> + fflag = 1;
> + break;
>   default:
>   usage();
>   } ARGEND
> @@ -23,7 +28,7 @@ main(int argc, char *argv[])
>   if (!argc)
>   usage();
>  
> - if (getpgrp() == getpid()) {
> + if (fflag || getpgrp() == getpid()) {
>   switch (fork()) {
>   case -1:
>   eprintf("fork:");

[hackers] setsid: add optional -f to force fork()

2020-07-14 Thread Hiltjo Posthuma 
Hi,

The below patch adds an -f flag to force fork(2)ing and creating a new process.


>From a75ef384c11b64732dd6a3adc9249ba6beb8a67e Mon Sep 17 00:00:00 2001
From: Hiltjo Posthuma 
Date: Tue, 14 Jul 2020 10:11:43 +0200
Subject: [PATCH] setsid: add optional -f to force fork()

---
 setsid.1 | 3 ++-
 setsid.c | 9 +++--
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/setsid.1 b/setsid.1
index d43bcfc..4df6439 100644
--- a/setsid.1
+++ b/setsid.1
@@ -1,4 +1,4 @@
-.Dd 2015-10-08
+.Dd 2020-07-14
 .Dt SETSID 1
 .Os sbase
 .Sh NAME
@@ -6,6 +6,7 @@
 .Nd run a command in a new session
 .Sh SYNOPSIS
 .Nm
+.Op Fl f
 .Ar cmd
 .Op Ar arg ...
 .Sh DESCRIPTION
diff --git a/setsid.c b/setsid.c
index 28d3442..3355b40 100644
--- a/setsid.c
+++ b/setsid.c
@@ -4,10 +4,12 @@
 
 #include "util.h"
 
+static int fflag = 0;
+
 static void
 usage(void)
 {
-   eprintf("usage: %s cmd [arg ...]\n", argv0);
+   eprintf("usage: %s cmd [-f] [arg ...]\n", argv0);
 }
 
 int
@@ -16,6 +18,9 @@ main(int argc, char *argv[])
int savederrno;
 
ARGBEGIN {
+   case 'f':
+   fflag = 1;
+   break;
default:
usage();
} ARGEND
@@ -23,7 +28,7 @@ main(int argc, char *argv[])
if (!argc)
usage();
 
-   if (getpgrp() == getpid()) {
+   if (fflag || getpgrp() == getpid()) {
switch (fork()) {
case -1:
eprintf("fork:");
-- 
2.27.0


-- 
Kind regards,
Hiltjo