From jzitt at josephzitt.com  Sun Jan  1 22:12:33 2006
From: jzitt at josephzitt.com (Joseph Zitt)
Date: Sun, 01 Jan 2006 22:12:33 -0800
Subject: [buug] Spaces within filenames in a bash script
Message-ID: <43B8C451.6020700@josephzitt.com>

Hi, all. This would seem to be an FAQ, but I haven't been quite able to 
get it to work after a lot of experimenting and digging around.

I'm using a bash script that I got from an article on an O'Reilly site 
to convert FLAC files to mp3s. (I'm guessing that it could easily be 
tweaked to do oggs, but the problem would be the same.) It's blowing up 
badly on files with spaces in the names:

#!/bin/bash
FILES=$(ls *.flac | cut -d '.' -f1)
for i in $FILES; do
         echo converting: $i.flac
         flac -sdc $i.flac | lame - $i.mp3
done

I've tried all sorts of different incantations, mostly throwing 
quotation marks in to see what would work, but no matter what I do, it 
takes a filename like "foo bar baz.flac" and treats it as three files, 
"foo", "bar", and "baz.flac".

Can someone suggest a tweak that will handle this (other than renaming 
the files to start with, which would be even more of a hassle)?

Thanks for any enlightenment.


From brian at dessent.net  Mon Jan  2 02:00:09 2006
From: brian at dessent.net (Brian Dessent)
Date: Mon, 02 Jan 2006 02:00:09 -0800
Subject: [buug] Spaces within filenames in a bash script
References: <43B8C451.6020700@josephzitt.com>
Message-ID: <43B8F9A9.630A0C3A@dessent.net>

Joseph Zitt wrote:

> #!/bin/bash
> FILES=$(ls *.flac | cut -d '.' -f1)
> for i in $FILES; do
>          echo converting: $i.flac
>          flac -sdc $i.flac | lame - $i.mp3
> done

You should consider using find instead of ls.  And it looks like what
you have would die if you had a filename with more than one "." in it.

# untested
find . -name \*.flac | while read F; do
    echo "converting: $F"
    flac -sdc "$F" | lame - "$(basename "$F" .flac).mp3"
done

By the way, just for simple commands the best way to do this is:

find /path -name \*.whatever -print0 | xargs -0 command

...which will handle filenames with spaces, quotes, tabs, newlines, and
anything else.

Brian


From Michael.Paoli at cal.berkeley.edu  Mon Jan  9 01:23:58 2006
From: Michael.Paoli at cal.berkeley.edu (Michael Paoli)
Date: Mon,  9 Jan 2006 01:23:58 -0800
Subject: [buug] Spaces within filenames in a bash script
In-Reply-To: <43B8C451.6020700@josephzitt.com>
References: <43B8C451.6020700@josephzitt.com>
Message-ID: <1136798638.43c22bae226cb@webmail.rawbw.com>

Quoting Joseph Zitt:

> tweaked to do oggs, but the problem would be the same.) It's blowing up
> badly on files with spaces in the names:
>
> #!/bin/bash
> FILES=$(ls *.flac | cut -d '.' -f1)
> for i in $FILES; do
>          echo converting: $i.flac
>          flac -sdc $i.flac | lame - $i.mp3
> done

You could try something roughly like:
#!/bin/sh
unset ret
for flac in *.flac
do
    if [ -f "$flac" ]; then
        #exists as ordinary file (or symlink to ordinary file)
        echo "$0: converting: $flac"
        b="`basename "$flac" .flac`"
        flac -sdc -- "$flac" | lame - -- "$b".mp3 && ret="${ret-0}"
    else
        if [ X'*.flac' != X"$flac" ] || >>/dev/null 2>&1 ls -d "$flac"; then
            #not an ordinary file
            1>&2 echo "$0: skipping $flac: not a file"
        fi
        ret=1
    fi
done
exit "$ret"

I also made some presumptions about flac and lame taking -- to indicate
end of all options - this tends to be generally true with most newer
UNIX/LINUX commands, but isn't necessarily supported on all commands.

Carefully study the man page stuff (e.g. bash(1) or sh(1)), paying
particular attention to various forms of quoting and command
substitution (and how they also interact).

Lots of stuff stuck in articles, web sites, etc., are probably more
often meant for or more useful for general illustrative examples, rather
than particularly robust and complete code examples (this is often
particularly the case in print when space may be at a premium).  Of
course lots of folks also write less than wonderfully robust code.

The example bit I did, above, is also just for illustrative purposes
:-).  It certainly makes some improvements, but it doesn't handle
everything ideally, e.g. ideally if flac failed (e.g. exited non-zero)
that should cause the script to return a non-zero value when it
completes.

references/excerpts:
bash(1)
basename(1)
http://home.comcast.net/~j.p.h/cus-faq-2.html#11
http://www.rawbw.com/~mp/unix/sh/