Re: Proposed doc updates

[Alexandre Duret-Lutz]

Hi Eric,

Some quick feedback

On Mon, Jan 24, 2005 at 06:22:04AM -0700, Eric Blake wrote:

> +Array assignment is a Bash extension, and is not portable.

> +The Bash extension @code{for (( exp1; exp2; exp3 ))} is not portable.

> +The @command{function} command in Bash is a non-portable alternate to

IMHO these do not deserve any mention.  It's not like a standard
feature that is not portable, or a non-standard feature that can get
in your way when writing apparantly sane scripts.  We can't list every
extension of every shell.

> +Most of the time, a Posix function can do everything that an alias can,
> +and more.  However, in shells that support both, it is worth remembering
> +that alias expansion occurs before filename expansion, leading to this
> +useful alias from
> address@hidden://lists.debian.org/debian-user/2003/06/msg01038.html)} that
> +supresses filename expansion for the duration of the find command:
> +
> address@hidden
> +$ @kbd{alias find='_find() @{ find "$@@"; set +f; unset _find; @}; set -f; 
> _find'}
> address@hidden example

I'm not convinced such discussion belongs to this section.  (But don't
feel strongly about this.)

> +The syntax @command{shift n} is not supported in older shells; instead
> +use a sequence of n repeated calls to @command{shift}.
> +

It would be useful to states which shells.  (So that people know whether
they must care, and for how long.)

>       (Limitations of Usual Tools): Add cross-reference to
>       EXEEXT. Document that FAT uses 2-second timestamp resolution.

> +On the other extreme, the @acronym{FAT} file system of @acronym{DOS},
> +still used by DJGPP and cygwin, has only a 2-second resolution.

>  fractional part, which can lead to incorrect results.  Normally this
>  is not a problem, but in some extreme cases you may need to use tricks
> -like @samp{sleep 1} to work around timestamp truncation bugs.
> +like @samp{sleep 2} to work around timestamp truncation bugs and the
> +coarse 2-second granularity of @acronym{FAT} file systems.

It's indeed a 2-second resolution, but a 5-second precision => use sleep 5!

http://sources.redhat.com/ml/bug-automake/2003/msg00016.html