Andreas,
How right you are! Still, I find it curious that in the context of the
while(TRUE) loop, I am allowed to do this 653 times, with failure on the
654th attempt. Perhaps there is something asynchronous going on? If I
eliminate the looping, it does indeed fail (as expected) on the first
attempt to close the pipe.
Regards
Ben
On 12/6/19 2:04 AM, Andreas Kersting wrote:
> Hi Benjamin,
>
> you cannot pipe to echo, since it does not read from stdin.
>
> echo just echos is first arg, i.e. echo /dev/stdin > /dev/null will echo the string "/dev/stdin"to /dev/stdout, which is redirected to /dev/null.
>
> Try
>
> p <- pipe("cat > /dev/null", open = "w")
>
> instead.
>
> Regards,
> Andreas
>
> 2019-12-06 02:46 GMT+01:00 Benjamin Tyner<btyner using gmail.com>:
>> Not sure if this is a bug, so posting here first. If I run:
>> cnt <- 0L
>> while (TRUE) {
>> cnt <- cnt + 1L
>> p <- pipe("echo /dev/stdin > /dev/null", open = "w")
>> writeLines("foobar", p)
>> tryCatch(close(p), error = function(e) { print(cnt); stop(e)})
>> }
>>
>> then once cnt gets to around 650, it fails with:
>>
>> [1] 654
>> Error in close.connection(p) : ignoring SIGPIPE signal
>>
>> Should I not be using pipe() in this way? Here is my sessionInfo()
>>
>> R version 3.6.0 (2019-04-26)
>> Platform: x86_64-pc-linux-gnu (64-bit)
>> Running under: Ubuntu 18.04.3 LTS
>>
>> Matrix products: default
>> BLAS: /home/btyner/R360/lib64/R/lib/libRblas.so
>> LAPACK: /home/btyner/R360/lib64/R/lib/libRlapack.so
>>
>> locale:
>> [1] LC_CTYPE=en_US.UTF-8 LC_NUMERIC=C
>> [3] LC_TIME=en_US.UTF-8 LC_COLLATE=en_US.UTF-8
>> [5] LC_MONETARY=en_US.UTF-8 LC_MESSAGES=en_US.UTF-8
>> [7] LC_PAPER=en_US.UTF-8 LC_NAME=C
>> [9] LC_ADDRESS=C LC_TELEPHONE=C
>> [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C
>>
>> attached base packages:
>> [1] stats graphics grDevices utils datasets methods base
>>
>> loaded via a namespace (and not attached):
>> [1] compiler_3.6.0
>>
>> Regards,
>> Ben
>>
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