[SOLVED] Problem-Simple bash script to copy the latest .jpg file

RCCollins · 11-23-2011, 01:26 AM

Hello,
I can not seem to get this simple script to work. I am trying to copy the most recently created .jpg file in a directory, I believe the problem is that that the .jpg file has parenthesis in its name, for example 00000(aaa)11111.jpg

Code:

cp "00000(aaa)11111.jpg" /var/www/html/archive/

Works fine, however my script does not

Code:

#!/bin/bash
cd /var/www/html/ftp/
LATEST= ls -t | head -1
cp "$LATEST" /var/www/html/archive/
exit

Any help would be appreciated

dive · 11-23-2011, 01:33 AM

It looks like that LATEST= line will print the result but not set LATEST. Try

Code:

LATEST=$(ls -1 | head -1)

Actually it is setting LATEST to "". It would be the same if you did

LATEST="" ls -l | head -1

fukawi1 · 11-23-2011, 01:46 AM

There are a number of ways to assign the output of a command to a variable in bash.

Code:

 LATEST=$(ls -t | head -1)

Code:

 LATEST=`ls -t | head -1`

will both have the same effect, for this example.

dive · 11-23-2011, 02:01 AM

Be aware though that `` is deprecated in favour of $()

David the H. · 11-23-2011, 09:57 AM

You really shouldn't be parsing the output of ls either.

http://mywiki.wooledge.org/ParsingLs
http://mywiki.wooledge.org/BashFAQ/087

Probably the safest way to find the newest (or largest, etc.) file is to run through the directory in a simple loop.

Code:

for file in *; do
	[[ -f $file && $file -nt $NEWEST ]] && NEWEST=$file
done

echo "$NEWEST"

Since it uses globbing, it's perfectly suitable for use with filenames containing whitespace, even newlines.

You also don't usually need head just to grab the first line of an input text. The built-in read can do it just as well. Use it in combination with process substitution to grab the output of a command instead of a file.

Code:

read -r topline < <( command )
echo "$topline"

grail · 11-23-2011, 10:37 AM

Well if we are looking at alternatives ... this one is a bit choppy but does the job:

Code:

find /path -type f -name '*.jpg' -printf '%T@\t%p\n' | sort -k1,1n | tail -n1 | cut -f2-

Of course if only looking in current directory I would set maxdepth as well.

RCCollins · 11-24-2011, 02:24 PM

Thanks to everyone for the great input!