Jim Cheetham wrote:
On Tue, Jun 10, 2008 at 6:34 PM, Douglas Royds <[EMAIL PROTECTED]> wrote:
ls -lh --time-style + $candidate | cut -d' ' -f9
Cut seems to be vulnerable to the number of spaces:
Yes, it is, as the space is the field separator, and fields may be
null -- which means it fails if there are spaces in the filename, but
I don't use them :-)
It will also fail if extra spaces are in the output of ls -l under
certain conditions ... but what are they?
$ ls -lh | cut -d' ' -f8
<--- This was the "total 1.5M" line
Yes, but I shouldn't have been cutting a -h line :-) because the
human-readable size output format changes under different conditions.
I should have left it as just -l.
That's what fooled me.
$ ls -lh | cut -b50-
Well, only if the output you don't want is always the same size :-)
What if the username wasn't 'root' or the size ~1.1Mb?
Good point
Was there meant to be something after the "+"?
According to the man page, --time-style takes a 'date' style +FORMAT
... and the format is null, which suppresses the output ... so
'--time- +' neatly drops the unwanted time field.
Aha! I observed that result, but didn't think to RTFM.
All this mucking around with ls is difficult, because the job of ls is
to produce human-readable output, and we're trying to turn it back in
to machine-readable. Probably better to use something like 'stat' in
the first place :-) except that 'stat -c %N' (which expands symlinks
for you) has an ugly output format ...however it can be sliced out
with one sed or two cut invocations, accurately.
candidate=$(stat -c %N $candidate|cut -d\` -f3|cut -d\' -f1)
or
candidate=$(stat -c %N /usr/bin/vi|sed -e "s/\`.*\`\(.*\)'/\1/")
Stat and ls are both in the Ubuntu coreutils package, so there should
be no problem with availability.
I hadn't met stat before.
PS: I resisted the urge to name the script "which, really?"
Mine is now called 'twhich' ... sort of "true which", also easy to
quickly add a t to the beginning of the previous command when I
remember I really want it :-)
Of course, all this would be generally much better done in a
programming language other than bash :-) but where's the fun in that?
-jim
What's sad here is that we actually think this is interesting.
Douglas.
=======================================================================
This email, including any attachments, is only for the intended
addressee. It is subject to copyright, is confidential and may be
the subject of legal or other privilege, none of which is waived or
lost by reason of this transmission.
If the receiver is not the intended addressee, please accept our
apologies, notify us by return, delete all copies and perform no
other act on the email.
Unfortunately, we cannot warrant that the email has not been
altered or corrupted during transmission.
=======================================================================
