Date: Wed, 14 Dec 2005 16:31:25 +1100 From: Norberto Meijome <freebsd@meijome.net> To: user <user@dhp.com> Cc: freebsd-questions@freebsd.org Subject: Re: I need a better way to loop in the shell... Message-ID: <439FAE2D.8000206@meijome.net> In-Reply-To: <Pine.LNX.4.21.0512132340550.8684-100000@shell.dhp.com> References: <Pine.LNX.4.21.0512132340550.8684-100000@shell.dhp.com>
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user wrote: > I always do loops in /bin/sh like this: > > for f in `cat file` ; do rm -rf $f ; done > > Easy. I like doing it like this. > > The problem is, when I am dealing with an input list that has multiple > words per line, this chops it up and treats every word as a new line... > > For instance, lets say I have a file full of filenames, like this: > > # cat file > > 10,000 Maniacs MTV Unplugged - 01 - These Are Days.mp3 > 10,000 Maniacs MTV Unplugged - 02 - Eat For Two.mp3 > 10,000 Maniacs MTV Unplugged - 03 - Candy Everybody Wants.mp3 > > and I try to use the above loop on it, it thinks that every word is a line > ... the above loop will attempt to delete the following files: > > 10,000 > Maniacs > MTV > Unplugged > - > 01 > - > These > > (and so on) > > Even if I quote the variable $f, like: > > for f in `cat file` ; do rm -rf "$f" ; done > > it still does the same thing. > > ----- > > So my question is, what is a nice simple way to loop in the shell, as > close to what I am doing above as possible, that does not have this > problem ? Should I just be using something other than `cat` ? Or what ? you can redefine the character(s) used by your shell for delimiting words after expansion. In Bash , this is the env var IFS. so , if you know there are no ;, you can say export IFS=";" [your loop here] export IFS= and you should be set. man bash for more info. Beto
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