similar to: pipe(): input to, and output from, a single process

I am not sure if `pipe()` works for this, but if it turns out that it does not, then you can use the processx package, e.g.: > p <- processx::process$new("sed", c("-l", "s/a/x/g"), stdin = "|", stdout = "|") > p$write_input("foobar\n") > p$read_output() [1] "foobxr\n" The `-l` sed flag is to make sed line-buffered,

Gabor, thanks. yes, managing the two-way communication is always a bit error-prone, as it depends on the input/output characteristics of the two ends -- they either match, or deadlock. it's too bad if polling is always *required* -- i'd think sometimes a programmer would be happy blocking, though other times one wants better control over when to block. cheers, Greg

hi. i'm building a package using autotools. to propagate the package version number from configure.ac to DESCRIPTION, i'm using a DESCRIPTION.in file. both of these files are "shar"'d below. i need to distribute the DESCRIPTION.in file, as ./configure will need it. but, "R CMD check" wants to look at DESCRIPTION, so i've let that also come into the package

On 13 March 2020 at 20:26, Greg Minshall wrote: | hi. i'd like to instantiate sed(1), send it some input, and retrieve | its output, all via pipes (rather than an intermediate file). | | my sense from pipe and looking at the sources (sys-unix.c) is that is | not possible. is that true? are there any thoughts of providing such a | facility? Octave had this already in the 1990s, see

Hey all, what is wrong with this command: system2("echo", env = c(VAR = "Hello World"), args = c("$VAR")) I am a bit confused, as help("system2") writes about the env option: > character vector of name=value strings to set environment variables. Is this option buggy, or am I using it just wrong? Thanks for your help Henning

Hi All; This problem has come about from trying to learn some of the review practices recommend by rOpensci. One of them is to use the package goodpractice. After installing goodpractice, it kept failing on my own packages which are under development, and I was concerned something was funny in my own , so I have a fork of the package rerddap, and I tested goodpractice on that. I get the

hi. this is sort of a software methodology question. i'm working on developing a package (with C source code). developing it, i use autotools, git, make, and such like. as a result, there are random files in my source code directory that "R CMD check" would rather not see. some of these files (such as .git and friends) i could arrange to move to "just above" my

hi. below is a small test case (hopefully minimal, though i'm still a bit confused about initializers). i would have guessed (and maybe i still would have been right) that one could re-use the name of a generic function for functions with different numbers of arguments. in the case below, class A's bB() queries the status of a single A object, so bB(A) (where here "A" is an

hi. i'm working on a package which only works if one (or both) of two libraries (Imlib2 and MagickWand) exist on the machine on which the package is compiled and executed. as currently written, the program purposely generates an error at *compile* time if neither library is available (thinking the earlier the user is notified, the less frustrating). is there a way of specifying this

withr:::set_makevars() can give that error if the makefile named by the 'old_path' argument (default "~/.R/Makevars) contains more than one definition of a variable of the form 'name=value'. You can see what file it is reading and its contents by using the trace() function: trace(withr:::set_makevars, quote({ cat(old_path, "\n"); writeLines(paste0(" ",

Chuck and Greg, Thanks a lot for your help! I have a much better understanding now of what is happening ?under the hood?. Kind Regards, Jason > On 31 May 2018, at 20:08, Greg Minshall <minshall at acm.org> wrote: > > Jason, > > as Chuck Berry (to whom, *thanks* for 'do {...} while(0)'!) suggested, > using grep, or even grep executed from find, such as >

On Fri, Jan 23, 2015 at 10:23:15PM +0100, Markus Doits wrote: > > On 23.01.15 22:16, Ralph B?hme wrote: > > On Fri, Jan 23, 2015 at 01:08:31PM -0800, Jeremy Allison wrote: > >> On Fri, Jan 23, 2015 at 10:05:44PM +0100, Markus Doits wrote: > >>> On 23.01.15 19:57, Miguel Medalha wrote: > >>>> I am using Samba 4.1.16 with smb2/3 and symbolic links are

I've written a python wrapper around the smbclient program, so that I can list/upload/download from Windows shares. Using smbclient 2.0.9 or Version 2.2.5-2 for Debian, my wrapper works well and is able to control the smbclient process via pipes well. With both smbclient 2.999+3.0cvs20020723-1 and 2.999+3.0.alpha20-3 (on a Debian box) the smbclient responses appear to be not always BEFORE the

Hello all, I am trying to get a better understanding of the underlying code for the stats::dpois function in R and, specifically, what happens under the hood when it is called. I finally managed to track down the C course at: https://github.com/wch/r-source/blob/trunk/src/nmath/dpois.c. It would seem that the dpois C function is taking a double for each of the x and lambda arguments so I am a bit

Dear members, I can't install "nser" package. It is not in cran but install_version and install_github both are not working: > install_version("nser",version = "1.4.0") Downloading package from url: https://cran.rstudio.com//src/contrib/Archive/nser/nser_1.4.0.tar.gz These packages have more recent versions available. It is

Numbers -- thanks. Another clever trick. On 5/25/2018 11:54 AM, Greg Minshall wrote: > Evan, > > are you really looking at numbers, or just at character strings (that, > in your case, happen to be numbers)? if just characters, this rather > odd combination of strsplit() and Reduce() might do the trick: > ---- >> x <- '10110111' >> print(x) > [1]

hi. if i'm reading correctly, "Writing R Extensions" appears to be inconsistent on the question of whether the arguments passed to a routine called via .Call() or .External() should considered read-only. section 5.2, "Interface functions .C and .Fortran", says ---- However, when character vectors are used other than in a read-only way, the .Call interface is much to be

It says that nser requires the most recent version of magrittr that you do not have installed. You must update magrittr before attempting to install nser: update.packages(oldPkgs = "magrittr") or at the prompt you were presented before, choose to update magrittr before installing nser. On Sun, Apr 9, 2023, 17:55 akshay kulkarni <akshay_e4 at hotmail.com> wrote: > Dear

Hi, I''m currently trying to install xapi on debian (unstable), following the following wiki page: http://wiki.xensource.com/xenwiki/XAPI_on_debian 1. Install squeeze 32-bits (it''s not specified on the wiki, but I guess it wont work with 64-bit as the xapi *.deb files are for 32). note: you must leave an unused 1mb partition somewhere when creating your

>>>>> Emil Bode >>>>> on Tue, 12 Jun 2018 12:00:42 +0000 writes: > I agree that calling it invalid is a bit confusing, but I?m not sure what the wording should be, as the problem is that the conversion to POSIXlt is failing. > The best solution would be to extend the whole POSIXlt-class, but that?s too much work. > I?ve done some experiments, and it