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Re: A request for addition of a command
From: |
James Youngman |
Subject: |
Re: A request for addition of a command |
Date: |
Mon, 27 Jul 2009 00:54:04 +0100 |
On Fri, Jul 24, 2009 at 8:17 PM, Kamil Dudka<address@hidden> wrote:
>> 2. Negative path to eliminate the part of the path.
>>
>> <path0> - <path1>
>>
>> This removes the <path1> from the end of <path0>.
>>
>> - <path0> + <path1>
>>
>> This removes the <path0> from the beginning of <path1>
>
> The algebra seems really strange to me. Has the '-' operator usual semantic
> of unary '-' (meaning inverse element with regards to binary operation '+')?
> Then should the following be always true:
> 1. -(-a) == a
> 2. a - b == a + (-b)
>
> Do we have any real life use-case for the operator '-'? I think concatenation
> with "/.." and/or sed invocation are mostly sufficient.
Or the word transformation operators /, %% and ## built into the shell.
$ x=foobar; echo ${x%%bar} ; echo ${x##foo}; echo ${x/oob/_}
foo
bar
f_ar
James.
- Re: A request for addition of a command, (continued)
- Re: A request for addition of a command, Kamil Dudka, 2009/07/24
- Re: A request for addition of a command, Pádraig Brady, 2009/07/24
- Re: A request for addition of a command, Jim Meyering, 2009/07/24
- Re: A request for addition of a command, Pádraig Brady, 2009/07/24
- [PATCH] doc: mention realpath in the readlink info, Pádraig Brady, 2009/07/24
- Re: A request for addition of a command, Pádraig Brady, 2009/07/24
Re: A request for addition of a command, Tak Ota, 2009/07/24
Re: A request for addition of a command,
James Youngman <=
Re: A request for addition of a command, Tak Ota, 2009/07/27