[PATCH 0/3] script: no logging for non-interactive shells

[PATCH 0/3] script: no logging for non-interactive shells

[Stanislav Brabec]

Many people use script in their shell initialization files. It has some 
unwanted consequences, e. g. logging commands from cron (and starting 
them in a pseudo-terminal and interactive shell). It could also result 
in a seemingly hanging applications:

For example:

echo -e './script\nTERM=linux mutt' | \
   at $(date -d "+1 minute 5 seconds" +%H:%M)

mutt will "hang" inside at, because it thinks that it is running in an 
interactive shell and waits for input.

That is why I wrote --interactive command line option. If it is set, 
script called from a non-interactive session will not log anything, just 
(optionally) execute -c argument and silently exit.

Note that similar behavior existed between f50473e and 3822032, but the 
new proposed behavior does not generate error.

-- 
Best Regards / S pozdravem,

Stanislav Brabec
software developer
---------------------------------------------------------------------
SUSE LINUX, s. r. o.                          e-mail: sbrabec@suse.cz
Lihovarská 1060/12                            tel: +49 911 7405384547
190 00 Praha 9                                 fax:  +420 284 084 001
Czech Republic                                    http://www.suse.cz/
PGP: 830B 40D5 9E05 35D8 5E27 6FA3 717C 209F A04F CD76

Re: [PATCH 0/3] script: no logging for non-interactive shells

[Karel Zak]

On Tue, Feb 10, 2015 at 10:30:35PM +0100, Stanislav Brabec wrote:
> Many people use script in their shell initialization files. It has some
> unwanted consequences, e. g. logging commands from cron (and starting them
> in a pseudo-terminal and interactive shell). It could also result in a
> seemingly hanging applications:
> 
> For example:
> 
> echo -e './script\nTERM=linux mutt' | \
>   at $(date -d "+1 minute 5 seconds" +%H:%M)
> 
> mutt will "hang" inside at, because it thinks that it is running in an
> interactive shell and waits for input.
> 
> That is why I wrote --interactive command line option. If it is set, script
> called from a non-interactive session will not log anything, just
> (optionally) execute -c argument and silently exit.

Would be better to learn people to fix their shell initialization
files to not call script(1) for non-interactive sessions?

    Karel

-- 
 Karel Zak  <kzak@redhat.com>
 http://karelzak.blogspot.com

Re: [PATCH 0/3] script: no logging for non-interactive shells

[Stanislav Brabec]

Karel Zak wrote:

> Would be better to learn people to fix their shell initialization
> files to not call script(1) for non-interactive sessions?

It makes sense.

>From 8fff32e65399ae07f70e12568d4d5278725673a7 Mon Sep 17 00:00:00 2001
From: Stanislav Brabec <sbrabec@suse.cz>
Date: Wed, 11 Feb 2015 15:02:10 +0100
Subject: [PATCH] script.1: Document behavior in non-interactive shells

And discourage users from such use.
---
 term-utils/script.1 | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/term-utils/script.1 b/term-utils/script.1
index 4573f07..f32030c 100644
--- a/term-utils/script.1
+++ b/term-utils/script.1
@@ -121,6 +121,26 @@ create garbage in the typescript file.
 .B script
 works best with commands that do not manipulate the screen, the results are
 meant to emulate a hardcopy terminal.
+.PP
+It is not recommended to run
+.B script
+in non-interactive shells. The inner shell of
+.B script
+is always interactive, and this could lead to unexpected results. If you use
+.B script
+in the shell initialization file (profile), you should use e. g.
+.RS
+.RE
+.sp
+.na
+.RS
+.nf
+if test -t 0 ; then
+    script
+fi
+.fi
+.RE
+.PP
 .SH ENVIRONMENT
 The following environment variable is utilized by
 .BR script :
-- 
2.2.2


-- 
Best Regards / S pozdravem,

Stanislav Brabec
software developer
---------------------------------------------------------------------
SUSE LINUX, s. r. o.                          e-mail: sbrabec@suse.cz
Lihovarská 1060/12                            tel: +49 911 7405384547
190 00 Praha 9                                 fax:  +420 284 084 001
Czech Republic                                    http://www.suse.cz/
PGP: 830B 40D5 9E05 35D8 5E27 6FA3 717C 209F A04F CD76

Re: [PATCH 0/3] script: no logging for non-interactive shells

[Karel Zak]

On Wed, Feb 11, 2015 at 03:07:52PM +0100, Stanislav Brabec wrote:
> Subject: [PATCH] script.1: Document behavior in non-interactive shells

 Applied, thanks :-)

-- 
 Karel Zak  <kzak@redhat.com>
 http://karelzak.blogspot.com