similar to: Clarification for readChar man page

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

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

I am curious why readLines() has a default (n=-1L) to read the full file while readChar() has no default for nchars= (i.e., readChar(file) is an error). Is there a technical reason for this? I often[1] see code like paste(readLines(f), collapse="\n") which would be better served by readChar(), especially given issues with the global string cache I've come across[2]. But lacking the

On Fri, 26 Jan 2024, Michael Chirico wrote: > I am curious why readLines() has a default (n=-1L) to read the full > file while readChar() has no default for nchars= (i.e., readChar(file) > is an error). Is there a technical reason for this? > > I often[1] see code like paste(readLines(f), collapse="\n") which > would be better served by readChar(), especially given

Is this possible? I've tried both writeChar() and writeBin() to no avail. My goal is to serialize(ascii=FALSE) an object to a connection but determine the size of the serialized object before hand: sobject <- serialize(object,NULL,ascii=FALSE) len <- nchar(sobject) # # run some code here to notify listener on other end of connection # how many bytes I'm getting ready to send #

My opinion is that the proposed feature would be greatly appreciated by users. I had always wondered if I was the only one doing paste(readLines(f), collapse="\n") all the time. It would be great to have the proposed, more straightforward way to read the whole file as a string: readChar("my_file.txt", -1) or even better readChar("my_file.txt") Thanks for your detailed

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

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,

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

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:

Hi R gurus, I'm trying to use a ReSTful web service from within R. Specifically, I need to make HTTP PUT requests. I'm able to make the request and that goes well enough, but I'm having trouble properly consuming the HTTP response. The problem comes in when I'm trying to parse out the response body. I get the length of the response body from the Content-Length header. I then try

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, > > >

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

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 noticed an issue where readChar does not return the correct value after a call to readline. It appears that readChar is not aware of the buffering, so it reads from the end of the buffer, rather than the current position in the file. This is a significant change of behavior from R-3.4.4. Below is a test case that I used to home in on the problem. --- p<-"test2.txt"

I have R code to read a binary header file, consisting of several readBin() and readChar() statements. I am currently using version R-2.2.1 (on x86_64, RH EL4) and have received the following error Error in readChar(fid, n = 1) : invalid UTF-8 input in readChar() This is strange because (a) I was able to read in this file successfully in previous versions of R (circa 2005) and (b) it

Hi, I'm trying to generate valid R code using R. Parts of the task is to read a sequence of characters from file and escape them such that they can be put in quotation marks to form a valid R code string. Example: Let the input file be (four rows containing ASCII 0-255 characters): abcdef<tab>ghijk\nlmno second row\t\a\\ fourth and so on... <EOF> Now, find escapeString() such

Hi, I'm trying to generate valid R code using R. Parts of the task is to read a sequence of characters from file and escape them such that they can be put in quotation marks to form a valid R code string. Example: Let the input file be (four rows containing ASCII 0-255 characters): abcdef<tab>ghijk\nlmno second row\t\a\\ fourth and so on... <EOF> Now, find escapeString() such

Hi all, Since I was having several problems trying to work with a large matrix I started to use the package R.huge but I'm having the following problem > x<-FileByteMatrix("covtype.data",nrow=581012,ncol=55) Error: cannot allocate vector of size 770.8 Mb In addition: Warning messages: 1: Reached total allocation of 447Mb: see help(memory.size) in: readChar(con = con, nchar =