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Subject: Re: /bin/sh starts with check in script
References: <56BB33E8.4080900@gmail.com>
To: Sergei G <sergeig.public@gmail.com>
Cc: questions-list freebsd <freebsd-questions@freebsd.org>
From: Jan Henrik Sylvester <me@janh.de>
Message-ID: <56BC9AC2.3070805@janh.de>
Date: Thu, 11 Feb 2016 15:29:22 +0100
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On 02/10/2016 13:58, Sergei G wrote:
> I came up with this solution to check if variable $line starts with a
> hash.  Basically I am checking if line is a comment in the configuration
> file.
> 
> #!/bin/sh
> if expr "${line}" : '#.*' > /dev/null; then
>   echo Ignoring comment line
> fi
> 
> I had to redirect to /dev/null, because expr prints a number to STDOUT. 
> Is there a better way to do this kind of string matching check in
> /bin/sh (not bash)?

[ "${line#\#}" != "$line" ] && echo comment

See the Parameter Expansion section of sh(1).

Cheers,
Jan Henrik