Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > gnu.bash.bug > #16555

Re: Return from function depending on number of parameters

Path csiph.com!goblin1!goblin.stu.neva.ru!usenet.stanford.edu!not-for-mail
From Chris Elvidge <celvidge001@gmail.com>
Newsgroups gnu.bash.bug
Subject Re: Return from function depending on number of parameters
Date Thu, 9 Jul 2020 17:48:41 +0100
Lines 36
Approved bug-bash@gnu.org
Message-ID <mailman.5.1594313334.2306.bug-bash@gnu.org> (permalink)
References <b1c19d38-64c0-f1ae-d08a-1ada435a0022@gmail.com> <20200706115026.GV22833@eeg.ccf.org> <re7hp9$ids$1@ciao.gmane.io>
NNTP-Posting-Host lists.gnu.org
Mime-Version 1.0
Content-Type text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding 7bit
X-Trace usenet.stanford.edu 1594313334 25094 209.51.188.17 (9 Jul 2020 16:48:54 GMT)
X-Complaints-To action@cs.stanford.edu
To bug-bash@gnu.org
Envelope-to bug-bash@gnu.org
X-Injected-Via-Gmane http://gmane.org/
User-Agent Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1
In-Reply-To <20200706115026.GV22833@eeg.ccf.org>
Content-Language en-GB
Received-SPF pass client-ip=116.202.254.214; envelope-from=gnu-bug-bash-3@m.gmane-mx.org; helo=ciao.gmane.io
X-detected-operating-system by eggs.gnu.org: First seen = 2020/07/09 12:48:47
X-ACL-Warn Detected OS = Linux 2.2.x-3.x [generic] [fuzzy]
X-Spam_score_int 43
X-Spam_score 4.3
X-Spam_bar ++++
X-Spam_report (4.3 / 5.0 requ) BAYES_00=-1.9, DKIM_ADSP_CUSTOM_MED=0.001, FORGED_GMAIL_RCVD=1, FORGED_MUA_MOZILLA=2.309, FREEMAIL_FORGED_FROMDOMAIN=1, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=1, NML_ADSP_CUSTOM_MED=0.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no
X-Spam_action no action
X-BeenThere bug-bash@gnu.org
X-Mailman-Version 2.1.23
Precedence list
List-Id Bug reports for the GNU Bourne Again SHell <bug-bash.gnu.org>
List-Unsubscribe <https://lists.gnu.org/mailman/options/bug-bash>, <mailto:bug-bash-request@gnu.org?subject=unsubscribe>
List-Archive <https://lists.gnu.org/archive/html/bug-bash>
List-Post <mailto:bug-bash@gnu.org>
List-Help <mailto:bug-bash-request@gnu.org?subject=help>
List-Subscribe <https://lists.gnu.org/mailman/listinfo/bug-bash>, <mailto:bug-bash-request@gnu.org?subject=subscribe>
X-Mailman-Original-Message-ID <re7hp9$ids$1@ciao.gmane.io>
X-Mailman-Original-References <b1c19d38-64c0-f1ae-d08a-1ada435a0022@gmail.com> <20200706115026.GV22833@eeg.ccf.org>
Xref csiph.com gnu.bash.bug:16555

Show key headers only | View raw


On 06/07/2020 12:50 pm, Greg Wooledge wrote:
> On Fri, Jul 03, 2020 at 07:00:54PM +0100, Chris Elvidge wrote:
>> I've used 'return $((!$#))' and 'return $[!$#]' to return an error if no
>> parameters given to function.
> 
> The problem with this is that it *always* returns from the function,
> even when paramters are given.
> 
> If you actually want to do what you said, you need a conditional check
> of some kind, either "if" or "||".
> 
> (($#)) || return 1
> 
> would be my preference, if you really do not want to give any kind of
> error message to indicate *why* you are returning with a failure code.
> 
> If you want to add an error message, then I would go with "if".
> 
> if ((! $#)); then
>    echo "usage: myfunc arg1 ..." >&2
>    return 1
> fi
> 
> 

This is a function only for me. The return comes after a help section.
[[ $# -eq 0 || "$1" =~ -h ]] &&  etc. No error message required, just an 
indication.

Thanks for the pointers.

-- 
Chris Elvidge
England

Back to gnu.bash.bug | Previous | Next | Find similar


Thread

Re: Return from function depending on number of parameters Chris Elvidge <celvidge001@gmail.com> - 2020-07-09 17:48 +0100

csiph-web