CODEWITHSUNDEEP
rstring-matching
harkmug
harkmug

Reputation: 2785

How do I mimic `ls foo*bar` in R?

Completely stumped, though it seems like a simple question that will be voted down very shortly as a duplicate, but I couldn't find the right "pattern" to search for the answer.

I am looking for files in a folder that match a dual pattern and then want to open them in R. So, assume list.files produces the following:

lf <- c("foo_23_bar.txt", "goo_42_mar.txt", "boo_42_bar.txt")

In command line, I would use ls foo*bar to find the first file, but in R, something like,

grep(paste("foo","bar",sep="|"),lf)

returns both files 1 and 3. I am not sure how to use the perl=TRUE option. Any help would be great. Thanks!

Upvotes: 1

Views: 199

Answers (3)

harkmug
harkmug

Reputation: 2785

Hmm .. one of the useful answers has disappeared. Anyway, here is exactly what I had in mind, combining Martin's and Michael's(?) answers:

list.files(path="data/",pattern=glob2rx("*foo*bar*"))

Or, as solved by Bingjun:

lf <- system("ls data/*foo*bar*")

This has the added benefit of providing filenames with path, making it simpler to read them into R directly.

Upvotes: 0

Bingjun
Bingjun

Reputation: 56

I usually use the system function. Check out here. http://stat.ethz.ch/R-manual/R-patched/library/base/html/system.html

Upvotes: 3

Martin Morgan
Martin Morgan

Reputation: 46876

Use glob2rx to get the corresponding regex

> glob2rx("foo*bar*")
[1] "^foo.*bar"

and

> grep(glob2rx("foo*bar*"), lf, value=TRUE)
[1] "foo_23_bar.txt"

Upvotes: 4

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