Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
67 views
in Technique[技术] by (71.8m points)

How to determine if you have an internet connection in R

Sometimes I need to download data from the internet. On occasions this has failed either because the website is down or because my computer has lost its internet connection.

Question: Is there some function in R which will return TRUE/FALSE as to whether I am connected to the internet?

question from:https://stackoverflow.com/questions/5076593/how-to-determine-if-you-have-an-internet-connection-in-r

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

The curl package has a function has_internet which tests by performing a nslookup:

curl::has_internet
## function(){
##    !is.null(nslookup("google.com", error = FALSE))
## }

Testing DNS is faster and may be more reliable than retrieving a URL because the latter might fail for unrelated reasons (e.g. firewall, server down, etc).


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...