Re: [minor] umask 400 causes here-{doc,string} failure

[Ilkka Virta]

On 11.3. 17:17, Stephane Chazelas wrote:
> $ bash -c 'umask 400; cat <<< test'
> bash: cannot create temp file for here-document: Permission denied

> Those shells use temporary files to store the content of the
> here-documents as the Bourne shell initially did, and open them
> in read-only mode to make it cat's stdin.
>
> When umask contains the 0400 bit, the file is created without
> read permission to the user, hence the error upon that second
> open().
> I can think of several ways to address it:
>
> 1- do nothing and blame the user
> 2- open the file only once for both
> writing the content and making it the command's stdin
> 3. use a pipe instead of a temp file
> 4. Reset the umask temporarily to 077

One more came to mind:

5. manually chmod() the tempfile to 0400 or 0600 if the open() for 
reading fails with EACCES, and then retry. Should be doable with a 
localized change to that particular error condition, without changing 
the overall behaviour.

> 2 would have my preference.


--
Ilkka Virta / itvirta@iki.fi