Ping a website in R

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I would like to create a script in R that pings a given website. I haven\'t found any information about this specific for R.

To start with, all I need is the informa

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终归单人心

2020-12-03 17:58
If you want to see if a website is responding to HTTP requests, you can test an URL in R with the RCurl library, which is an R interface to the curl HTTP client library.

Example:
```
> library(RCurl);
> getURL("http://www.google.com")
[1] "<!doctype html><ht....
```
If you want to examine the response code (for 200, 404, etc.) you will need to write a custom function to pass as the "header" option to getURL().
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我在风中等你

2020-12-03 17:59

We can use a system2 call to get the return status of the ping command in the shell. On Windows (and probably linux) following will work :

ping <- function(x, stderr = FALSE, stdout = FALSE, ...){
    pingvec <- system2("ping", x,
                       stderr = FALSE,
                       stdout = FALSE,...)
    if (pingvec == 0) TRUE else FALSE
}

# example
> ping("google.com")
[1] FALSE
> ping("ugent.be")
[1] TRUE

If you want to capture the output of ping, you can either set stdout = "", or use a system call:

> X <- system("ping ugent.be", intern = TRUE)
> X
 [1] ""                                                         "Pinging ugent.be [157.193.43.50] with 32 bytes of data:" 
 [3] "Reply from 157.193.43.50: bytes=32 time<1ms TTL=62"       "Reply from 157.193.43.50: bytes=32 time<1ms TTL=62"      
 [5] "Reply from 157.193.43.50: bytes=32 time<1ms TTL=62"       "Reply from 157.193.43.50: bytes=32 time<1ms TTL=62"      
 [7] ""                                                         "Ping statistics for 157.193.43.50:"                      
 [9] "    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss)," "Approximate round trip times in milli-seconds:"          
[11] "    Minimum = 0ms, Maximum = 0ms, Average = 0ms"

using the option intern = TRUE makes it possible to save the output in a vector. I leave it to the reader as an exercise to rearrange this in order to get some decent output.

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抹茶落季

2020-12-03 18:10
To get the status code
```
library(httr)

b <- GET("http://www.google.com")

b$status_code

[1] 200 
```
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心在旅途

2020-12-03 18:11
RCurl::url.exists works for localhost (where ping doesn't always) and is faster than RCurl::getURL.
```
> library(RCurl)
> url.exists("google.com")
[1] TRUE
> url.exists("localhost:8888")
[1] TRUE
> url.exists("localhost:8012")
[1] FALSE
```
Note that it is possible to set the timeout (which by default is rather long)
```
> url.exists("google.com", timeout = 5) # timeout in seconds
[1] TRUE
```
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