Displaying 20 results from an estimated 10000 matches similar to: "newbie: closing unused connection + readline"
2008 Aug 20
1
read.csv : double quoted numbers
Hello;
I am new user of R; so pardon me.
I am reading a .txt file that has around 50+ numeric columns with '\t'
as separator. I am using read.csv function along with colClasses but
that fails to recognize double quoted numeric values. (My numeric
values are something like "1,001.23"; "1,008,000.456".) Basically
read.csv fails with - "scan() expected 'a
2017 Dec 14
2
cannot destroy connection (?) created by readLines in a tryCatch
Consider this code. This is R 3.4.2, but based on a quick look at the
NEWS, this has not been fixed.
tryCatch(
readLines(tempfile(), warn = FALSE)[1],
error = function(e) NA,
warning = function(w) NA
)
rm(list=ls(all.names = TRUE))
gc()
showConnections(all = TRUE)
If you run it, you'll get a connection you cannot close(), i.e. the
last showConnections() call prints:
?
2017 Dec 15
1
cannot destroy connection (?) created by readLines in a tryCatch
Thanks for tracking this down. Yeah, I should use suppressWarnings(),
you are right.
Although, readLines() might throw another warning, e.g. for incomplete
last lines,
and you don't necessarily want to suppress that.
TBH I am not sure why that warning is given:
? con <- file(tempfile())
? open(con)
Error in open.connection(con) : cannot open the connection
In addition: Warning message:
In
2006 Aug 25
2
increasing the # of socket connections
Dear "R-help"ers,
using snow on socket connections, I ran into the following error
> cl <- makeSOCKcluster(hosts)
Error in socketConnection(port = port, server = TRUE,
blocking = TRUE : all connections are in use
with "showConnections(all=T)" showing 50 open connections.
As - for administrative reasons - I would prefer to use snow's
SOCK capabilities (instead
2017 Dec 14
4
cannot destroy connection (?) created by readLines in a tryCatch
On Thu, Dec 14, 2017 at 7:56 PM, Gabriel Becker <gmbecker at ucdavis.edu> wrote:
> Gabor,
>
> You can grab the connection and destroy it via getConnection and then a
> standard close call.
Yeah, that's often a possible workaround, but since this connection
was opened by
readLines() internally, I don't necessarily know which one it is. E.g.
I might open multiple
2009 May 21
3
file descriptor leak in getSrcLines in R 2.10.0 svn 48590
I noticed the following file descriptor leak when I couldn't remove
a package unless I shut down the R session that had loaded and
used it. The function that triggered the problem printed the output
of a call to parse(). Each time one prints a srcref a connection is
opened and not closed. It looks like it happens in
as.character.srcref's
call to getSrcLines, which has some logic I
2008 Sep 02
1
R Newbie: quantmod and zoo: Warning in rbind.zoo(...) : column names differ
Hello;
I am trying following but getting a warning message : Warning in
rbind.zoo(...) : column names differ, no matter whatever I do.
Also I do not want to specify column names manually, since I am just
writing a wrapper function around getSymbols to get chunks of data
from various sources - oanda, dividends etc.
I tried giving col.names = T/F, header = T/F and skip = 1 but no help.
I think
2000 Dec 20
1
unlink() is not synchronized with existing connections (PR#783)
> # creating a file
> cat("sddfasdf", file="tempfile")
> showConnections()
class description mode text isopen can read can write
> con <- file("tempfile", "r")
> readLines(con)
[1] "sddfasdf"
Warning message:
incomplete final line in: readLines(con, n, ok)
> showConnections()
class description mode text isopen
2007 Aug 14
1
makeSOCKcluster
Hi,
I am attempting to implement a mixed (windows/linux) snow sockets
parallelism in R, but am running into difficulties similar to a post made
Aug 31, 2006 under the same subject heading. I feel like I may be one or
two non-obvious steps away from getting it all working, but I'm stuck. If
anyone can shed some light on this (I believe Prof. Tierney stated that he
has successfully run a
2000 Dec 20
0
showConnections() does not show closed (or non-opened) connections though help says so (PR#784)
help on showConnections explains parameter
all logical: if true all connections, including closed ones and the standard ones are displayed. If false only open user-created connections are included.
but
> # create a file
> cat("TITLE extra line", "2 3 5 7", "", "11 13 17", file="ex.data",
+ sep="\n")
>
2007 Jul 03
1
bug in closing gzfile-opened connections?
Hi,
I am making multiple calls to gzfile() via read.table(), e.g.
> x <- read.table( gzfile( "xxx.gz" ) )
After i do this many times (I haven't counted, but probably between 50 and
100 times) I get the error message:
Error in open.connection(file, "r") : unable to open connection
In addition: Warning message:
cannot open compressed file 'xxx.gz'
however, I
2000 Dec 20
1
showConnections() does not show closed (or non-opened) connections though help says so
help on showConnections explains parameter
all logical: if true all connections, including closed ones and the standard ones are displayed. If false only open user-created connections are included.
but
> # create a file
> cat("TITLE extra line", "2 3 5 7", "", "11 13 17", file="ex.data",
+ sep="\n")
>
2002 Jan 10
1
Closing binary file connections
Hi all,
I'm writing a function that read data from a binary file. I want to
close all opened connections, but it failed:
> showConnections()
description class mode text isopen can read can write
3 "daten/t5_all.mea" "file" "rb" "binary" "opened" "yes" "no"
4 "daten/t5_all.mea"
2000 Dec 20
1
Inconsistency in creating/opening/closing/destroying connections (PR#787)
I expected close() to be the opposite of open(), but
> # create a connection
> con <- file("ex.data")
> # open it
> open(con, "w")
> # close it
> close(con)
> # re-open it
> open(con, "w")
Error in open.connection(con, "w") : invalid connection
>
> con
Error in summary.connection(x) : invalid connection
> # is obviously
2017 Dec 14
0
cannot destroy connection (?) created by readLines in a tryCatch
On Thu, Dec 14, 2017 at 12:17 PM, G?bor Cs?rdi <csardi.gabor at gmail.com>
wrote:
> On Thu, Dec 14, 2017 at 7:56 PM, Gabriel Becker <gmbecker at ucdavis.edu>
> wrote:
> > Gabor,
> >
> > You can grab the connection and destroy it via getConnection and then a
> > standard close call.
>
> Yeah, that's often a possible workaround, but since this
2017 Dec 14
0
cannot destroy connection (?) created by readLines in a tryCatch
This has nothing to do with on.exit. It is an iteraction between where
the warning is signaled in 'file' and your _exiting_ warning handler.
This combination has the same issue,
tryCatch(file(tempfile(), "r"), warning = identity)
showConnections(all = TRUE)
as does
options(warn=2)
file(tempfile(), "r")
showConnections(all = TRUE)
I haven't looked at the
2010 Sep 16
3
funciones en R potencialmente peligrosas via web?
Hola:
Para el desarrollo del nuevo PluginR de Tiki (para poder ejecutar
scripts de R desde Tiki: en páginas Wiki, hojas de cálculo web, etc,
http://dev.tiki.org/PluginR ), por ahora estamos usando la lista de
funciones que se usaban en el proyecto r-php, y que fueran heredadas por
la extensión R de MediaWiki.
Como r-php se hizo hace algunos años (2006), me pregunto si alguien sabe
si hay
2017 Dec 14
0
cannot destroy connection (?) created by readLines in a tryCatch
Gabor,
You can grab the connection and destroy it via getConnection and then a
standard close call. (it actually lists that it is "closed" already, but
still in the set of existing connections. I can't speak to that difference).
> tryCatch(
+ readLines(tempfile(), warn = FALSE)[1],
+ error = function(e) NA,
+ warning = function(w) NA
+ )
[1] NA
>
2005 Sep 18
0
Updated rawConnection() patch
Here's an update of my rawConnection() implementation. In addition to
providing a raw version of textConnection(), this fixes two existing
issues with textConnection(): one is that the current textConnection()
implementation carries around unprotected SEXP pointers, the other is
a performance problem due to prolific copying of the output buffer as
output is accumulated line by line.
This new
2009 Aug 11
1
reading heterogeneous CSV
Greetings, all.
I've got a datafile I've been working with that has an ideosyncratic,
heterogeneous format. It's grossly like:
[...]
DISKREAD,metadata about disks
MEM,metadata about memory
ZZZZ,observation-identifier,time,date
DISKREAD,observation-identifier,data about disks
MEM,observation-identifier,data about memory
[ and repeat for each observation ]
What I've done in