[perl #38901] perlfaq8 correction

> [[email protected] - Wed Apr 12 01:27:26 2006]:
> 
> 
> This is a bug report for perl from [email protected],
> generated with the help of perlbug 1.35 running under perl v5.8.7.
> 
> 
> -----------------------------------------------------------------
> About "How do I find out if I’m running interactively or not?":
> 
> The snippet with the solution for POSIX systems emits a die() if
> /dev/tty cannot be opened. I think it should not die but rather
> print "no tty". The situation that there's no /dev/tty can happen
> on boot time on Linux systems.
> 
> So my suggestion is:
> 
>            use POSIX qw/getpgrp tcgetpgrp/;
>            if (!open(TTY, "/dev/tty")) {
>                print "no tty\n";
>            } else {
>                $tpgrp = tcgetpgrp(fileno(*TTY));
>                $pgrp = getpgrp();
>                if ($tpgrp == $pgrp) {
>                    print "foreground\n";
>                } else {
>                    print "background\n";
>                }
>            }
> 
> Regards,
> 	Slaven
> 

Your suggestion has been added to the FAQ with the following change.

Change 27905 by stevep@stevep-mccoy on 2006/04/19 16:32:26

	Changes to perlfaq8 "How do I find out if I'm running interactively 
	or not?" suggested by Slaven Rezic in RT #38901: perlfaq8 correction

Affected files ...

... //depot/perl/pod/perlfaq8.pod#50 edit

Differences ...

==== //depot/perl/pod/perlfaq8.pod#50 (text) ====

@@ -1005,13 +1005,19 @@
 the current process group of your controlling terminal as follows:
 
     use POSIX qw/getpgrp tcgetpgrp/;
-    open(TTY, "/dev/tty") or die $!;
-    $tpgrp = tcgetpgrp(fileno(*TTY));
-    $pgrp = getpgrp();
-    if ($tpgrp == $pgrp) {
-        print "foreground\n";
+    
+    # Some POSIX systems, such as Linux, can be
+    # without a /dev/tty at boot time. 
+    if (!open(TTY, "/dev/tty")) {
+        print "no tty\n";
     } else {
-        print "background\n";
+        $tpgrp = tcgetpgrp(fileno(*TTY));
+        $pgrp = getpgrp();
+        if ($tpgrp == $pgrp) {
+            print "foreground\n";
+        } else {
+            print "background\n";
+        }
     }
 
 =head2 How do I timeout a slow event?