Open file in R which related corresponding to system date

Question

I would like to use R to verify system date first prior to go to my default work directory to open today and the day before data file.

The reason is my data file been labelled as 20151101_xxx.csv which is yyyymmdd_xxx.csv. Is it possible R can perform this action?

Please consider reading up on [ask] and how to produce a [reproducible example](http://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example). It makes it easier for others to help you. — Heroka, Nov 17 '15 at 12:59
Is `paste0(format(Sys.Date()-1,"%Y%m%d"),"_xxx.csv")` what you wanted ? — etienne, Nov 17 '15 at 13:06

Rentrop · Accepted Answer · 2015-11-17T19:34:41.213

0

You can use list.files to do that as follows:

days <- gsub("-", "", Sys.Date() - 0:1)
list.files(path = "YOUR PATH", pattern = paste0(days, "_", collapse = "|"))

Which gives you all files starting with yyyymmdd_.

To only get files in the format yyyymmdd_xxx.csv do the following:

list.files(path = "YOUR PATH", pattern = paste0(days, "_xxx.csv", collapse = "|"))

This should give you all files containing yyyymmdd_xxx.csv.

edited Nov 17 '15 at 19:34

answered Nov 17 '15 at 13:07

Rentrop

A tip: you can use `Sys.Date()` in combination with format: `format(Sys.Date(), format="%Y%m%d")` – Heroka Nov 17 '15 at 13:12
Thanks. unfortunately i have multiple file 20151101_xxx.csv, 20151101_yyy.csv, 20151031_xxx.csv, 20151031_yyy, etc. However, I just would like to open file 20151101_xxx.csv and 20151031_xxx.csv. – Chinteck Nov 17 '15 at 13:36
i get what i want but edit the below comment: days – Chinteck Nov 17 '15 at 13:39

1 Answers1