GNU bug report logs - #27942
Bug regarding "touch" command

Previous Next

Full log

View this message in rfc822 format

From: L A Walsh <coreutils <at> tlinx.org>
To: Paul Eggert <eggert <at> cs.ucla.edu>
Cc: 27942 <at> debbugs.gnu.org, yalavarthi.pavankumar.123 <at> gmail.com
Subject: bug#27942: Bug regarding "touch" command
Date: Fri, 04 Aug 2017 20:44:56 -0700

Paul Eggert wrote:
> L A Walsh wrote:
>>> You run "touch -". Whatever file stdout happens to be associated 
>>> with, gets touched. It's the same idea as "cat -", except with stdout 
>>> rather than stdin.
>>>
>>
>> The difference between that and updating due to write activity being
>> mostly that ctime is also written?
> 
> No, that's not a difference. Try running 'touch foo; strace touch foo; 
> strace touch - >>foo'. I did that, and saw the same system call being 
> used to alter foo's last-modified time, in both strace outputs.
---
	So the touch command does the same as: 

 echo -n >>'stdout-file'   ?

What was the use-case that touch needed to have
the new feature?

*curious sort*

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.