find the extension of a csv file in r

To find the extension of a csv file in R, you can use regular expressions with string manipulation functions. For example:

# define a csv file name
file_name <- "data_file.csv"

# extract the file extension using regular expressions
file_extension <- sub(".*\\.(.*)", "\\1", file_name)

# print the file extension
print(file_extension)
213 chars
9 lines

This code will output "csv", which is the extension of the provided file name "data_file.csv".

The sub() function is used to replace a regular expression pattern with a replacement string, and it uses .*\\. to match any characters before the period (which is escaped with \ to treat it as a literal period rather than a regular expression wildcard) that precedes the file extension. The \\1 in the replacement string represents the captured group in the pattern, which is the file extension.