[R] system2 commands with backslash

[Henrik Bengtsson]

system2("sed", args=c("-i", "s/oldword\\s/newword/g", "d:/junk/x/test.tex"))

/Henrik

On Fri, Oct 11, 2013 at 8:58 AM, David Winsemius <dwinsemius at comcast.net> wrote:
>
> On Oct 10, 2013, at 8:16 AM, Zev Ross wrote:
>
>> Hi All,
>>
>> I'm trying to edit a file in place using system2 and sed from within R. I can get my command to work unless there is a backslash in the command in which case I'm warned about an "unrecognized escape". So, for example:
>>
>> system2("sed -i s/oldword/newword/g d:/junk/x/test.tex") # works fine
>> system2("sed -i s/oldword\s/newword/g d:/junk/x/test.tex") # does not work in R (the command works on the command line)
>>
>> I've experimented with double slashes to escape the \s,
>
> Wouldn't you want to double the backslashes instead?
>
>> I've tried the "shell" command, I've tried experimenting with shQuote and can't seem to get around the "unrecognized escape" issue.
>>
>> By the way, it would be preferable to have a solution that avoided using double backslashes etc because, unfortunately, in my real-world example, I'm actually replacing double slashes and would prefer not to have quadruple slashes etc.
>>
>> I'm using Windows 7, 64 bit.
>>
>> Zev
>>
>> --
>> Zev Ross
>> ZevRoss Spatial Analysis
>> 120 N Aurora, Suite 3A
>> Ithaca, NY 14850
>> 607-277-0004 (phone)
>> zev at zevross.com
>>
>> ______________________________________________
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>> 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
> Alameda, CA, USA
>
> ______________________________________________
> 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.