Check if a URL is online — check

Check if a URL is online by making a HEAD request. Returns TRUE if the URL is reachable and the status code is between 200 and 399 (inclusive). Returns FALSE otherwise.

Usage

check_url(url, timeout_ms = 5000)

Arguments

url: link to check
timeout_ms: timeout in milliseconds

Value

list with online status, status code, and message

Details

This function is useful for checking the availability of a server or resource before attempting to access it. In particular, it is used by ed_info() to check if the ERDDAP server is online before making requests to it since the underlying rerddap::info() crashes R if url is offline.

Examples

check_url("https://coastwatch.pfeg.noaa.gov/erddap/griddap/NOAA_DHW.html")
#> $online
#> [1] FALSE
#> 
#> $status_code
#> [1] 403
#> 
#> $message
#> [1] "Server is online with status code: 403"
#>