[R] Re: Need help with pipe()

[Ronnen Levinson]

Hi.

I have further experimented with the pipe() issue and found a workaround:
putting the instructions in a batch file.
It prepends two lines to the output of the pipe() instruction, but
otherwise seems to work.

-- Ronnen --

P.S. I am using binaries from a CRAN mirror. Uninstalling and reinstalling
R1.6.1 did not affect my results.

      my.pipe <- function(s,batch.file="pipetemp.bat") {
     + cat(s, file=batch.file)
     + pipe(batch.file)
     + }
     >
     > run.gawk <- "gawk '{print $0}' textfile"
     > cat("hello\ngoodbye\n",file="textfile")
     > readLines("textfile")
     [1] "hello"   "goodbye"
     > readLines(pipe(run.gawk))
     character(0)
     > readLines(pipe("echo shalom"))
     Error in readLines(pipe("echo shalom")) : cannot open the
     connection
     In addition: Warning message:
     cannot open cmd `echo shalom'
     > readLines(my.pipe(run.gawk))
     [1] ""
     [2] "D:\\My Documents\\@ARC\\@logger data>gawk '{print $0}'
     textfile "
     [3] "hello"
     [4] "goodbye"
     > readLines(my.pipe("echo shalom"))
     [1] ""
     [2] "D:\\My Documents\\@ARC\\@logger data>echo shalom "
     [3] "shalom"
     > version
              _
     platform i386-pc-mingw32
     arch     i386
     os       mingw32
     system   i386, mingw32
     status
     major    1
     minor    6.1
     year     2002
     month    11
     day      01
     language R
     >

Ronnen Levinson wrote:

> Hello.
>
> I have an R program that calls gawk (GNU Awk 3.06 for Windows) from
> within pipe() to preprocess a large file before it is read into a data
> frame with read.table().
>
> I've recently upgraded from Win98SE to WinXP, and have also upgraded
> from R1.5.0 to R1.6.1 over the past month or so. This program worked
> before the upgrade(s), but now fails. I observe the following sort of
> behavior with R1.6.1 under WinXP:
>
> > cat("hello\ngoodbye\n",file="textfile")
> > readLines("textfile")
> [1] "hello"   "goodbye"
> > readLines(pipe("gawk '{print $0}' textfile"))
> character(0)
> #  Note: R pauses for about 10 seconds before returning "character(0)"
> > readLines(pipe("echo hello"))
> Error in readLines(pipe("echo hello")) : cannot open the connection
> In addition: Warning message:
> cannot open cmd `echo hello'
> > version
>          _
> platform i386-pc-mingw32
> arch     i386
> os       mingw32
> system   i386, mingw32
> status
> major    1
> minor    6.1
> year     2002
> month    11
> day      01
> language R
> >
>
> gawk is in my system path, and I can successfully run it from a command
> window.
>
> Hence, I have the following questions:
>
> (1) Is pipe() supported in R1.6.1 under WinXP?
> (2) Can anyone suggest how to get pipe("gawk...") to work again?
>
> Thanks,
>
> Ronnen.
>
> P.S. E-mailed cc:s of replies posted to the list would be appreciated.
>
> --
> Ronnen Levinson, Ph.D.            \/      RML27 at cornell.edu
> scientist                         ||      http://ronnen.com
> Lawrence Berkeley National Lab    /\      fax 425.955.1992
>
> ======================================
> Take my word, the mockingbird'll
> sing the saddest kind o' song
> he knows things are wrong
> and he's right
>
> -- Johnny Mercer, "Blues in the Night"
> ======================================

--
Ronnen Levinson, Ph.D.            \/      RML27 at cornell.edu
scientist                         ||      http://ronnen.com
Lawrence Berkeley National Lab    /\      fax 425.955.1992

======================================
It is no secret that organized crime in America takes in over forty billion
dollars a year.
This is quite a profitable sum, especially when one considers that the
Mafia
spends very little for office supplies.

-- Woody Allen
======================================


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