Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!bsu-cs!dhesi
From: dhesi@bsu-cs.bsu.edu (Rahul Dhesi)
Newsgroups: comp.unix.questions
Subject: Re: Regular Expression delimiters
Message-ID: <6710@bsu-cs.bsu.edu>
Date: 11 Apr 89 17:30:38 GMT
References: <993@n8emr.UUCP>
Reply-To: dhesi@bsu-cs.bsu.edu (Rahul Dhesi)
Organization: CS Dept, Ball St U, Muncie, Indiana
Lines: 22

In article <993@n8emr.UUCP> lwv@n8emr.UUCP (Larry W. Virden) writes:
>
>Using sed as a simple example of a complex situation, how would one code
>a shell program to invoke sed so that the arguments passed would always be
>valid?...
>sed -e /$ans/ filename


First quote those slashes:

   # works from /bin/sh
   pattern="`echo "$ans" | sed -e 's/\//\\\\\\//g'`"
   sed -e "/$pattern/d" filename

Count those backslashes carefully.

What UNIX badly needs is a way of specifying out-of-band characters.
The current quoting scheme causes problems because a level of quoting
is removed at each level of interpretation.
-- 
Rahul Dhesi <dhesi@bsu-cs.bsu.edu>
UUCP:    ...!{iuvax,pur-ee}!bsu-cs!dhesi