listing the files in a directory using regular expressions
On Sun, Oct 14, 2012 at 3:13 AM, siddu479 <onlyfordigitalstuff at gmail.com> wrote:
Hi Experts, This might be silly question that I am asking, but no way as I am new to R. I want to list the files in a directory using regular expression like A_B*_C*.csv etc. How to make this possible in R ? I tried like this list.files(dir=".", pattern="A_B*_C*.csv") but this gives no output, whereas list.files(.... pattern="*.csv") giving all the .csv files in the output, which I do not want.
1. Always read the help file: ?list.files The argument name is path=, not dir=. 2. Also note that the pattern must be specified as a regular expression and not a glob (as would be specified in a command line shell). For example, the B* part of the expression in your post means 0 or more B's. It does not mean B followed by anything else. If you want to use globs rather than regular expressions see ?glob2rx
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