CODEWITHSUNDEEP
r
Zaynab
Zaynab

Reputation: 233

Reading from file in R when I have a part of its name

How can I read from a file in R when I have only a part of its name including starting or ending characters?

Thanks

Upvotes: 2

Views: 499

Answers (2)

Spacedman
Spacedman

Reputation: 94202

There is also Sys.glob which will expand patterns using stars and question marks according to glob syntax.

Here it is wrapped in a function to match filenames of the form "first*last" where "*" is anything. If you really have stars or other special chars in your filename... then you need to do a bit more.. Anyway:

> match_first_last = function(first="", last="", dir=".")
   {Sys.glob(
      file.path(dir,paste(first,"*",last,sep=""))
      )
    }


# matches "*" and so everything:
> match_first_last()
[1] "./bar.X" "./foo.c" "./foo.R"

# match things starting `foo`    
> match_first_last("foo")
[1] "./foo.c" "./foo.R"

# match things ending `o.c`
> match_first_last(last="o.c")
[1] "./foo.c"

# match start with f, end in R
> match_first_last("f","R")
[1] "./foo.R"

Upvotes: 0

Robert Krzyzanowski
Robert Krzyzanowski

Reputation: 9344

You can use list.files, which has a pattern argument, to try to match as close as you can.

writeLines(c('hello', 'world'), '~/tmp/example_file_abc')
filename <- list.files(path = '~/tmp', pattern = 'file_abc$', full.names = TRUE)[1]
readLines(filename)
# [1] "hello" "world"

Upvotes: 5

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