Thanks for your help and for the info on the website. I did not know what to call regular expressions and so I could not search for them. Cheers! d
On Mon, May 24, 2010 at 7:08 PM, <Richard.Cotton at hsl.gov.uk> wrote:
I am making a list of all the files in a folder and I want to exclude one file called "proj.current". ?This is the 31st file in a folder. Currently I use the command: tdirs <- list.files(pattern="proj.")[-31] However I would like to exclude it based on its name and not the
position. You need to update the pattern in the regular expression to look for strings beginning with "proj.", but not having "current" afterwards. My first thought was to use perl style regular expressions, but apprently this isn't supported. tdirs <- list.files(pattern = "proj\\.(?!current)", perl=TRUE) ? #Throws error Instead, you're probably better off doing it in two steps. tdirs <- list.files(pattern="proj\\.") tdirs <- tdirs[tdirs != "proj.current"] Notice the difference between "proj." and "proj\\.". ?The first means 'proj followed by any character', and the second means 'proj followed by a dot'. ?See http://www.regular-expressions.info/quickstart.html for more info on regexes. Regards, Richie. Mathematical Sciences Unit HSL ------------------------------------------------------------------------ ATTENTION: This message contains privileged and confidential information intended for the addressee(s) only. If this message was sent to you in error, you must not disseminate, copy or take any action in reliance on it and we request that you notify the sender immediately by return email. Opinions expressed in this message and any attachments are not necessarily those held by the Health and Safety Laboratory or any person connected with the organisation, save those by whom the opinions were expressed. Please note that any messages sent or received by the Health and Safety Laboratory email system may be monitored and stored in an information retrieval system. ------------------------------------------------------------------------ Think before you print - do you really need to print this email? ------------------------------------------------------------------------ ------------------------------------------------------------------------ Scanned by MailMarshal - Marshal's comprehensive email content security solution. Download a free evaluation of MailMarshal at www.marshal.com ------------------------------------------------------------------------
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