Date: Sat, 09 Sep 2017 11:27:55 -0400 From: Ernie Luzar <luzar722@gmail.com> To: Yuri Pankov <yuripv@gmx.com> Cc: Polytropon <freebsd@edvax.de>, "freebsd-questions@freebsd.org" <freebsd-questions@freebsd.org> Subject: Re: script code for end-line Message-ID: <59B4087B.2070005@gmail.com> In-Reply-To: <c8715d2d-cb1f-592b-7541-a556fa5645a7@gmx.com> References: <59B332A3.1000205@gmail.com> <20170909030257.d2718c00.freebsd@edvax.de> <c8715d2d-cb1f-592b-7541-a556fa5645a7@gmx.com>
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Yuri Pankov wrote:
> On Sat, 9 Sep 2017 03:02:57 +0200, Polytropon wrote:
>> On Fri, 08 Sep 2017 20:15:31 -0400, Ernie Luzar wrote:
>>>
>>> I have a file that has blank lines with ^M in position one.
>>>
>>> I have this if [ "$end-line" = "^M"]; then
>>>
>>>
>>> Is that the correct way to code that between the quotes?
>>
>> That will only match the literal string ^M (^ and M).
>> String evaluation and comparison at this low level
>> isn't a native skill of sh. There is a way of encoding
>> characters as octal values, such as \015 for \r, which
>> equals ^M and 0x0D, but /bin/test (which is [) can only
>> compare strings.
>>
>> Here is a terrible workaround (not tested):
>>
>> if [ `echo ${end-line} | od -x | head -n 1 | awk '{ print $2 }'` =
>> "000d" ]; then
>> ... do something ...
>> fi
>>
>> Check if there is already a tool for what you're trying
>> to accomplish (e. g., tr, sed, recode, iconv). ;-)
>
> Actually, you can insert real ^M characters and /bin/test should be able
> to handle them - press ctrl+V ctrl+M.
> .
>
I read the man page on the test command and did not come away with the
syntax to use in a script. An example showing usage inside of the "if"
statement sure would be more helpful to understand how it works.
Thanks
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