similar to: Writing character vectors with embedded nulls to a connection

Hi, Here's a patch to the readChar manual page (R-trunk as of today) that better clarifies readChar's return value. It could use some work as I'd also like to add some text about using nchar() to find the length of the string that readchar() returns, but I'm unsure which of type="bytes" or type="chars" to mention. Is it type="chars"? Index:

Trying to copy the (binary) header of a input file directly to an output file, I've had repeatable seg faults. The call: writeChar(hdr, outfh, nchars=6144) when hdr just contains one empty string seems to be the culprit. The stack traces weren't all that illuminating, with sig 11 in memory-related functions following this. But in src/main/connections.c it looks like do_writechar

Thanks to all who have responded. My concern was to be able to write a csv file that can have line feeds in string columns chr(10). Why? Excel allows line feeds chr(10) within cells and line breaks chr(13)+chr(10) at line ending, but the windows version of R automatically replaces \n by \r\n in writing and \r\n by \n in reading (text mode). The clues for a solution came from Brian Ripley and

Hi, The man page for readBin has a small typo: --- a/src/library/base/man/readBin.Rd +++ b/src/library/base/man/readBin.Rd @@ -58,7 +58,7 @@ writeBin(object, con, size = NA, endian \code{readBin} and \code{writeBin} read and write C-style zero-terminated character strings. Input strings are limited to 10000 - characters. \code{\link{readChar}} and \code{\code{writeChar}} +

I've now tested with: > R.version.string [1] "R Under development (unstable) (2024-02-16 r85931)" and all of the previously mentioned examples now work as expected on macOS. Thanks for the quick fix, Jenny On Thu, Feb 15, 2024 at 8:02?AM Tomas Kalibera <tomas.kalibera at gmail.com> wrote: > > On 2/14/24 23:43, Jennifer Bryan wrote: > > Hello, > > >

Full_Name: Ken Yap Version: 1.6.1 OS: Linux (SuSE 8.0) Submission from: (NULL) (129.78.64.5) I'm trying to copy a file using readBin and writeBin. (The reason is to be able to pipe PostScript or PDF output to a socket later, this is just an experiment.) I do: zz <- file("foo.ps", "rb") r <- readBin(zz, character(), 1000000) yy <- file("bar.ps",

Hello, I've noticed a specific type of pipe() usage that works in released R, but not in r-devel. In 4.3.2 on macOS, I can write to a connection returned by pipe(), i.e. "hello, world" prints here: > R.version.string [1] "R version 4.3.2 (2023-10-31)" > con <- pipe("cat") > writeLines("hello, world", con) hello, world But in r-devel on

Tony Plate wrote: > ligges@statistik.uni-dortmund.de wrote: > >> tplate@blackmesacapital.com wrote: >> >> >>> I've noticed that seek(con, 0, "end", rw="r") on a file connection >>> does not always work correctly after a write (R 2.1.0 on Windows). >>> >>> [Is a call to fflush() needed inside file_seek() in

Full_Name: Hugh C. Pumphrey Version: 1.4.1 OS: Linux (Debian Woody) Submission from: (NULL) (129.215.133.170) The function readChar() appears to have some type of problem with memory allocation. I don't know if "memory leak" is the correct term but if one uses readChar() many times, the R binary grows in size until it eats all your memory and swap space. The code enclosed below

Dear all, I have written a little R program to convert images. See below. Within the loop over j (the filenames) memory consumption grows constantly. rm( ... ) inside the loop did not help. Memory does not grow if I remove the writeBin statements between the two #-------- marks. But obviously this is not solution I want... Thanks for any advice. Manfred Baumstark P.S. As I'm new to R:

Tomas, Thank you for the explanation. I see in the documentation: "These functions are intended to be used with binary-mode connections." So I see how using it on a text connection is undefined, and not a bug. An error or warning when attempting to use a it on a text connection would be helpful considering how the behavior has changed in R-3.5. On Tue, May 29, 2018 at 3:09 AM, Tomas

I have recently been using writeChar and writeBin to write binary files. These functions makes it very easy to write OS-independent files, which I am very happy with. I have however found a few issues, best illustrated by a short example > con <- file("test", open = "wb") > writeChar(as.character(c("ab", "ab")), nchars = c(3), con = con,

Full_Name: Johnny Accot Version: 1.5.1 OS: Linux Submission from: (NULL) (198.4.83.52) Hi. I'm having a problem with the binary read/write functions. I'm writing a device driver in R (why not?) and of course I have to send a couple commands to the device. Typically, I send one byte, receive one acknowledgement byte, send another byte, receive an ACK, and so on. At least this is what

This is just to let people know that I'm going to try to put together a little package of binary file read/write functions for R, along the lines described in my message in r-help. I'm going to do it first in R for Windows using a DLL written in Delphi; I'll let people comment on that, and once the design settles down, I'll redo the external code in C so that it should be portable

Is there any way to write (8-bit) bytes to a file which works on all [R] platforms? I have been looking at 1) writeBin 2) writeChar 3) cat and neither of them manage to write arbitrary sequences of bytes (0-255). For instance, I would like to create a binary file of length three containing the bytes 0, 1 and 0. I [R] I have the following vector of bytes: bfr <- c(0,1,0) 1) For

Hi, I am trying to read in records from an old main frame file. Each record is 640 bytes. I had some success using the following statement: iconv(readChar(con, nchars=640, useBytes = TRUE),from="IBM037",to="",sub="#") What I have found, however, is that ocassionally a record will contain a Null halfway through, which causes readChar() not to read the rest of the

I have some functions that write an external text file for postprocessing by another program. Some instructions to the other program need to be indicated by null values (\000 or ^@). The function currently uses code like: writeChar(rawToChar(as.raw(0)), con) where con is a connection to the file. Previous to version 2.8.0 this worked fine. With 2.8.0 it still works, but I get a warning

Hi, I am fairly new to DTrace, and wanted to ask something regarding synchronization objects. I have a multithreaded C++ program in which I use semaphores (POSIX version) for synchronization. I was interested in using DTrace to figure out the total time for which each thread in my application sleeps, blocked on a semaphore, i.e., as a result of sem_wait() call. In order to measure this, I

Hi all, Given the recent CRAN push to prevent examples writing to the working directory, is there any interest in fixing base R examples that write to the working directory? A few candidates are the graphics devices, file.create(), writeBin(), writeChar(), write(), and saveRDS(). I'm sure there are many more. One way to catch these naughty examples would be to search for unlink() in

I'm trying to import a matrix created in PARI/GP into R but am having problems. The data in the text file has entries separated by commas but the rows themselves are separated by semicolons rathen than being on a new line. Is there a way to get R to recognise that ";" means start a new row ? -- View this message in context: