Re: -ls0

[James Youngman]

On Fri, Dec 30, 2011 at 12:35 AM, Karl Berry <address@hidden> wrote:
> James or anyone,
>
> I've been in the habit of using find -ls to record all files in a given
> hierarchy.  Of course, parsing the output of that becomes problematic
> when a file name contains a newline or other special characters.  So
> what I really want is -ls0, where the entries are delimited with nulls
> instead of newlines.

Why not just use \0 in the format specification?

~$ f="hello
world"
~$ echo "$f" | od -c
0000000   h   e   l   l   o      \n   w   o   r   l   d  \n
0000015
~$ touch "$f"
~$ find . -maxdepth 1 -name 'hello*' -printf '[%p]\0'
[./hello ?world]~$ find . -maxdepth 1 -name 'hello*' -printf '[%p]\0'|cat
[./hello
world]~$ find . -maxdepth 1 -name 'hello*' -printf '[%p]\0'|od -c
0000000   [   .   /   h   e   l   l   o      \n   w   o   r   l   d   ]
0000020  \0
0000021
~$ rm "$f"


> In the case of symlinks, I think the " -> " suffices to separate the
> symlink name from the target name.  That is, I'm willing to accept the
> lossage if a filename contains that string.  Less likely than a newline,
> anyway, and anything involving nulls would greatly complicate the
> parsing of the output.  Oh, maybe it should be \n->\n, that would be
> even less probable.

Alternatively, emit the symlinks into a separate file with -fprintf.

> I thought I would be able to use -printf to get the equivalent, but this
> appears to be impossible.  Aside from formatting trivialities, I don't
> see a directive or option or other setting to print the exact filename
> the way that -print0 does.  Am I missing something obvious?  Is there a
> way for -printf to print the raw file name?  Or the escaped (as in -ls)
> filename, for that matter?

Unprintable/unusual characters are escaped only when the output is
going to a tty.  See the info node "Unusual Characters in File Names"
in the GNU find manual.

> Also, I don't see a way to get the " -> " in symlink entries (without
> running a separate find for symlinks only), but I guess it's ok for my
> purposes to just unconditionally use %l.

You could use \( -type l -fprintf symlinks "$format" \) -o \( -fprintf
nonsymlinks "$format" \)

> The closest I could get was this:
>  find -printf "%i %k %M %n %u %g %s %T+ %p\n->\n%l\0"
>
> BTW, if/when there is an equivalent way to do it using -printf, I think
> it would be good to state it in the manual (Node: Print File
> Information), as well as mentioning `ls -dils'.

James.
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