Signals in R Programming Language
Here’s the translation of the Go code to R, formatted in Markdown suitable for Hugo:
Our example demonstrates how to handle signals in R. This can be useful for gracefully shutting down a program or stopping input processing when it receives certain signals.
library(parallel)
# Create a function to handle the signal
handle_signal <- function(sig) {
cat("\n")
cat(sig, "\n")
stopCluster(cl)
quit(save = "no")
}
# Register the signal handlers
tools::pskill(Sys.getpid(), tools::SIGINT)
tools::pskill(Sys.getpid(), tools::SIGTERM)
# Create a cluster for parallel processing
cl <- makeCluster(1)
# Start the main process
cat("awaiting signal\n")
# Use tryCatch to handle the signals
tryCatch({
while(TRUE) {
Sys.sleep(1)
}
},
interrupt = function(e) {
handle_signal("interrupt")
},
error = function(e) {
handle_signal("terminated")
})
In this R script:
We use the
parallel
library to create a cluster, which is somewhat analogous to creating a goroutine in the original example.We define a
handle_signal
function that prints the signal received and performs cleanup operations.We register signal handlers for SIGINT and SIGTERM using
tools::pskill
.We create a cluster using
makeCluster
, which will be used to demonstrate cleanup on program termination.The main part of the program is an infinite loop inside a
tryCatch
block. This allows us to catch and handle the signals.When a signal is received, the appropriate handler is called, which prints the signal type, stops the cluster, and exits the program.
To run this program:
Rscript signals.R
The program will block, waiting for a signal. By pressing Ctrl+C (which the terminal shows as ^C), we can send a SIGINT signal, causing the program to print “interrupt” and then exit.
$ Rscript signals.R
awaiting signal
^C
interrupt
This example demonstrates how to handle signals in R, allowing for graceful shutdown or interruption of long-running processes.