One-liner R: remove data frame columns by names

Sometime, I want to remove some columns from my data. What I did in that case, is found out what are the unwanted column ids and removed those. It's just a couple of lines in R. But why not write a function to do the job and also some error handling. So next time, I just copy and paste!

rm.col.by.name <- function(dat, colname.list){

l1 = length(colname.list)
l2 = which(colnames(dat) %in% colname.list)

if(length(l2) == 0) {
    warning('Did not find any matching columns. Check input column names, please.')
}

if(length(l2) > 0 & length(l2) < l1) {
    warning('Did not find all matching columns. Only those found are removed.')
    return(dat[,-c(l2)])
} 

if(length(l2) > 0 & length(l2) == l1) {
    return(dat[,-c(l2)])
}

}