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

[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 <hil...@codemadness.org>
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