ntg-context - mailing list for ConTeXt users
 help / color / mirror / Atom feed
From: Pablo Rodriguez via ntg-context <ntg-context@ntg.nl>
To: ntg-context@ntg.nl
Cc: Pablo Rodriguez <oinos@gmx.es>
Subject: Re: check installed program using Lua
Date: Tue, 2 Nov 2021 19:59:14 +0100	[thread overview]
Message-ID: <330529dd-d972-35f5-c8b0-f047be8d41e4@gmx.es> (raw)
In-Reply-To: <A89D28B3-0B0D-4C82-8C0D-43EB65AF7C47@bittext.nl>

On 11/1/21 3:10 PM, Taco Hoekwater via ntg-context wrote:
>> [...]
>> Is there a way to wrap os.exec() in the sample so that it only runs if
>> "dir" is available?
>
> if os.which(‘dir’) then
>   ...
> end
>
> But note that os.which() may be unreliable in various cases (like it
> will fail for shell/command interpreter builtins, in cron jobs, in
> special scripted environments, and may incorrectly succeed for
> disabled/forbidden commands), as it just runs through the PATH
> environment variable to check for executable file existence.
Many thanks for your reply, Taco.

This is exactly what I needed.

> Often times, it is better to just try to run the command to see if
> that produces satisfactory results.
It makes sense, but I cannot do that on foreign computers.

Many thanks for your help again,

Pablo

--
http://www.ousia.tk
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage  : http://www.pragma-ade.nl / http://context.aanhet.net
archive  : https://bitbucket.org/phg/context-mirror/commits/
wiki     : http://contextgarden.net
___________________________________________________________________________________

  reply	other threads:[~2021-11-02 18:59 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-01 13:26 Pablo Rodriguez via ntg-context
2021-11-01 14:10 ` Taco Hoekwater via ntg-context
2021-11-02 18:59   ` Pablo Rodriguez via ntg-context [this message]
2021-11-01 16:13 ` Hans Hagen via ntg-context
2021-11-02 19:01   ` Pablo Rodriguez via ntg-context

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=330529dd-d972-35f5-c8b0-f047be8d41e4@gmx.es \
    --to=ntg-context@ntg.nl \
    --cc=oinos@gmx.es \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).