Dear R-users, It is my understanding that cat(shQuote(a.string)) should print the origintal a.string. Is this right? I am not sure cat() correctly prints strings which are generated by triple-shQuote():> shQuote(shQuote("a"))[1] "\"\\\"a\\\"\""> cat(shQuote(shQuote(shQuote("a"))), '\n')"\"\\"a\\"\<file://\\"a\\"\>"" As you can see the latter string has fewer quoting '\' than the former. cat() of double shQuote works as expected:> shQuote("a")[1] "\"a\""> cat(shQuote(shQuote("a")), '\n')"\"a\""> version_ platform i386-pc-mingw32 arch i386 os mingw32 system i386, mingw32 status major 2 minor 6.1 year 2007 month 11 day 26 svn rev 43537 language R version.string R version 2.6.1 (2007-11-26) Am I missing something? Thanks, Vadim ________________________________ Note: This email is for the confidential use of the named addressee(s) only and may contain proprietary, confidential or privileged information. If you are not the intended recipient, you are hereby notified that any review, dissemination or copying of this email is strictly prohibited, and to please notify the sender immediately and destroy this email and any attachments. Email transmission cannot be guaranteed to be secure or error-free. Jump Trading, therefore, does not make any guarantees as to the completeness or accuracy of this email or any attachments. This email is for informational purposes only and does not constitute a recommendation, offer, request or solicitation of any kind to buy, sell, subscribe, redeem or perform any type of transaction of a financial product. [[alternative HTML version deleted]]
On 7/23/2008 12:20 PM, Vadim Organovich wrote:> Dear R-users, > > It is my understanding that cat(shQuote(a.string)) should print the origintal a.string. Is this right?No, cat(a.string) should print the original a.string. shQuote(a.string) adds quotes so that a.string can be used in the shell.> I am not sure cat() correctly prints strings which are generated by triple-shQuote(): > >> shQuote(shQuote("a")) > [1] "\"\\\"a\\\"\"" >> cat(shQuote(shQuote(shQuote("a"))), '\n') > "\"\\"a\\"\<file://\\"a\\"\>""That's a very strange result. I tried the obsolete version of R that you're using, and I didn't see it. I get this: > cat(shQuote(shQuote(shQuote("a"))), '\n') "\"\\"a\\"\"" Duncan Murdoch> As you can see the latter string has fewer quoting '\' than the former. > cat() of double shQuote works as expected: > >> shQuote("a") > [1] "\"a\"" >> cat(shQuote(shQuote("a")), '\n') > "\"a\"" >> version > _ > platform i386-pc-mingw32 > arch i386 > os mingw32 > system i386, mingw32 > status > major 2 > minor 6.1 > year 2007 > month 11 > day 26 > svn rev 43537 > language R > version.string R version 2.6.1 (2007-11-26) > Am I missing something? > > Thanks, > Vadim > > ________________________________ > Note: This email is for the confidential use of the named addressee(s) only and may contain proprietary, confidential or privileged information. If you are not the intended recipient, you are hereby notified that any review, dissemination or copying of this email is strictly prohibited, and to please notify the sender immediately and destroy this email and any attachments. Email transmission cannot be guaranteed to be secure or error-free. Jump Trading, therefore, does not make any guarantees as to the completeness or accuracy of this email or any attachments. This email is for informational purposes only and does not constitute a recommendation, offer, request or solicitation of any kind to buy, sell, subscribe, redeem or perform any type of transaction of a financial product. > > [[alternative HTML version deleted]] > > ______________________________________________ > 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.
I feel like it now belongs to r-devel more than to r-help.
My output was garbled because I sent the original message as HTML, sorry about
that.
Your output, "\"\\"a\\"\"", is what I get too.
That is
> cat(shQuote(shQuote(shQuote("a"))), '\n')
"\"\\"a\\"\""
, which I think should be "\"\\\"a\\\"\"".
Actually, the R's output, "\"\\"a\\"\"", is
not even a valid string literal, that is> x <- "\"\\"a\\"\""
fails.
Now, by cat() being the inverse of shQuote() I mean printing the same literal as
it goes into shQuote, quotes included:> cat(shQuote("a"), '\n')
"a"
whereas> cat("a", '\n')
a ## no quotes
If cat() is not the inverse of shQuote() in the above sense, what is?
Thanks,
Vadim
________________________________________
From: Duncan Murdoch [murdoch at stats.uwo.ca]
Sent: Wednesday, July 23, 2008 1:10 PM
To: Vadim Organovich
Cc: r-help at r-project.org
Subject: Re: [R] shQuote and cat
On 7/23/2008 12:20 PM, Vadim Organovich wrote:> Dear R-users,
>
> It is my understanding that cat(shQuote(a.string)) should print the
origintal a.string. Is this right?
No, cat(a.string) should print the original a.string. shQuote(a.string)
adds quotes so that a.string can be used in the shell.
> I am not sure cat() correctly prints strings which are generated by
triple-shQuote():
>
>> shQuote(shQuote("a"))
> [1] "\"\\\"a\\\"\""
>> cat(shQuote(shQuote(shQuote("a"))), '\n')
>
"\"\\"a\\"\<file://\\"a\\"\>""
That's a very strange result. I tried the obsolete version of R that
you're using, and I didn't see it. I get this:
> cat(shQuote(shQuote(shQuote("a"))), '\n')
"\"\\"a\\"\""
Duncan Murdoch
> As you can see the latter string has fewer quoting '\' than the
former.
> cat() of double shQuote works as expected:
>
>> shQuote("a")
> [1] "\"a\""
>> cat(shQuote(shQuote("a")), '\n')
> "\"a\""
>> version
> _
> platform i386-pc-mingw32
> arch i386
> os mingw32
> system i386, mingw32
> status
> major 2
> minor 6.1
> year 2007
> month 11
> day 26
> svn rev 43537
> language R
> version.string R version 2.6.1 (2007-11-26)
> Am I missing something?
>
> Thanks,
> Vadim
>
> ________________________________
> Note: This email is for the confidential use of the named addressee(s) only
and may contain proprietary, confidential or privileged information. If you are
not the intended recipient, you are hereby notified that any review,
dissemination or copying of this email is strictly prohibited, and to please
notify the sender immediately and destroy this email and any attachments. Email
transmission cannot be guaranteed to be secure or error-free. Jump Trading,
therefore, does not make any guarantees as to the completeness or accuracy of
this email or any attachments. This email is for informational purposes only and
does not constitute a recommendation, offer, request or solicitation of any kind
to buy, sell, subscribe, redeem or perform any type of transaction of a
financial product.
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> 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.
Note: This email is for the confidential use of the named addressee(s) only and
may contain proprietary, confidential or privileged information. If you are not
the intended recipient, you are hereby notified that any review, dissemination
or copying of this email is strictly prohibited, and to please notify the sender
immediately and destroy this email and any attachments. Email transmission
cannot be guaranteed to be secure or error-free. Jump Trading, therefore, does
not make any guarantees as to the completeness or accuracy of this email or any
attachments. This email is for informational purposes only and does not
constitute a recommendation, offer, request or solicitation of any kind to buy,
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