[R] How to get the string '\'?

[Peng Yu]

On Sun, Nov 15, 2009 at 6:05 PM, David Winsemius <dwinsemius at comcast.net> wrote:
>
> On Nov 15, 2009, at 6:35 PM, Peng Yu wrote:
>
>> My question was from replacing a pattern by '\\'. How to replace '/'
>> in string by '\'?
>>
>> string='abc/efg'
>> gsub('/','\\',string)
>
> No,  that was most definitely _not_ your posed question. If you want now to
> change your question and supply a reproducible example, that's fine, just
> don't claim that your mind should have been read more properly that it was,
> .... please.

Sorry for the misunderstanding. I realized that the answer to the
first question could not solve my original question (but I thought it
could). So I stated my original question.

> The problem with your _second_ question is that the printed representation
> of "\" is a problem because of its special use as an escape symbol. So
> sometimes it needs to be displayed as "\\". What gets written to the screen
> may be different that the internal representation. Look at the results of:
>> string='abc/efg'
>> cat(gsub('/','\\\\',string), file="test.txt")
>
> You should see:
> abc\efg
>
> ...although at the screen you would see:
>
>> string='abc/efg'
>> gsub('/','\\\\',string)
> [1] "abc\\efg"
>
> The first "\" escapes second "\" which in turn allows whatever follows to be
> interpreted as "escaped", while the third "\" escapes the 4th "\" so that it
> can be examined by the R interpreter as a real "\".
>
>
> --
> David.
>>
>> On Sun, Nov 15, 2009 at 5:07 PM, David Winsemius <dwinsemius at comcast.net>
>> wrote:
>>>
>>> ?cat
>>>
>>>> cat("\\")
>>>
>>> \
>>>
>>>
>>> On Nov 15, 2009, at 5:30 PM, Peng Yu wrote:
>>>
>>>> I can not get the string '\'. Could somebody let me know how to get it?
>>>>
>>>>> print('\')
>>>>
>>>> +
>>>> +
>>>>>
>>>>> print('\\')
>>>>
>>>> [1] "\\"
>>>>
>>>> ______________________________________________
>>>> R-help at r-project.org mailing list
>>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>>> PLEASE do read the posting guide
>>>> http://www.R-project.org/posting-guide.html
>>>> and provide commented, minimal, self-contained, reproducible code.
>>>
>>> David Winsemius, MD
>>> Heritage Laboratories
>>> West Hartford, CT
>>>
>>>
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>
> David Winsemius, MD
> Heritage Laboratories
> West Hartford, CT
>
>