file-scan.r

## file-scan.r
## Function to find a pattern in files with user-defined extension (.r by default)
## Returns file name and approximate row matches if positive.
## -------------------------------------------------------
## Author: Laura Tremblay-Boyer ([email protected])
## Written on: March 26, 2013
## Time-stamp: <2013-03-26 16:19:28 Laura>

file.scan <- function(pattern, dir=getwd(), fpattern=NA, ftype=".r") {

    nfiles <- list.files(dir)
    if(!is.na(fpattern)) nfiles <- nfiles[grep(fpattern, nfiles)]
    if(!(ftype=="all")) nfiles <- nfiles[grep(sprintf("%s$",ftype),nfiles)]
    if(length(nfiles)==0) print("No files found")


    sfunk <- function(wf) {
        ss <- scan(wf, "character", sep="\n", blank.lines.skip=FALSE)
        gf <- grep(pattern, ss)
        if(length(gf)>0) {
            return(list("filename"=wf, "row.numbers"=gf))
        }else{return(NULL)}
    }

    fs <- sapply(nfiles, sfunk)
    fs <- fs[!sapply(fs,is.null)]

    return(fs)
}