Quoting Michael Sims <[EMAIL PROTECTED]>: > [EMAIL PROTECTED] wrote: > > A quick note. If you are grepping the output of a ps command, > > enclose the first character of your regexp in square brackets. For > > example: > > > > ps aux | grep [l]pr > > > > This still lists all the processes that contain the string "lpr", but > > it will not match the grep process itself anymore. > > Why is that? Isn't a bracket expression containing only one character > exactly the > same as the character by itself? Am I missing something blindingly obvious? > :) >
As you point out, the brackets with one character amount to a range of one character. The "[l]pr" regexp is intrepreted as "lpr", but the grep command show up in ps as "grep [l]pr". This prevents grep from matching its own process as it is output by ps. -Roberto Sanchez ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
