Dear R Team
I have a question about the system/system2 command in R on linux. My goal is to
run a system command (which can take a long time) and to detect if it was
successful or not. If i understood correctly the return value of system should
give me exactly this information. However if i try to do this, system returns
0, even if i interrupt the execution with CTRL-C (which is the event i would
like to detect). Here is an example (just piping /dev/zero to /dev/null) to
illustrate the behavior after pressing CTRL-C.
> ret <- system("cat /dev/zero > /dev/null"); print(ret)
^C[1] 0
I also tried to use a tryCatch block to detect this event but pressing CTRL-C
during the execution of the system command does not result in a capture of this
interrupt event. Only releasing resources is called which happens in any case:
> tryCatch({
+ ret <- system("cat /dev/zero > /dev/null"); print(ret)
+ }, interrupt = function(ex) {
+ cat("An interrupt was detected.\n");
+ print(ex);
+ }, error = function(ex) {
+ cat("An error was detected.\n");
+ print(ex);
+ }, finally = {
+ cat("Releasing resources...");
+ cat("done\n");
+ })
^C[1] 0
Releasing resources...done
Is there still a way to find out if the user stopped the R script while the
system command was running?
R version 2.14.1 (2011-12-22)
Platform: x86_64-unknown-linux-gnu (64-bit)
Kind regards
Dimos Gaidatzis
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