[SOLVED] maxSIZE of a file.

Hitboxx · 05-25-2009, 11:18 PM

Hi,

A program from my sister's lab, I'm not much into Unix programming but I tried my best as I know but not getting the desired output. I believe it should return the maximum size of the file in some_dir.

Code:

maxSIZE=`ls -IR $1 | grep ' ^- ' | cut -c 35-42 | sort -n | tail -l`
echo "The maximum size of the file in $1 is $maxSIZE bytes"

OUTPUT:
[user@host]sh 3a.sh some_dir
The maximum size of file in some_dir is bytes.

As you see, it isn't returning the value but just a blank space as bytes. A little help please, thanks.

colucix · 05-26-2009, 02:30 AM

Your command uses the -I (capital ai) option of ls instead of -l (lowercase el), hence the output is null due to the cut command which actually has nothing to cut.

Hitboxx · 05-26-2009, 04:57 AM

That too returns the same null. Any other ideas?

Sergei Steshenko · 05-26-2009, 05:09 AM

Quote:

Originally Posted by Hitboxx

That too returns the same null. Any other ideas?

Take the very first part of the command, i.e.

Code:

ls -IR $1

, replace $1 with an actual file (directory ?) name, run the command and copy-paste the results here.

Guttorm · 05-26-2009, 05:15 AM

ls -lSr . |tail -1 |cut -d' ' -f5

Hitboxx · 05-26-2009, 05:30 AM

@Sergei,

Quote:

[jukeboxhero@Mothership ~]$ ls -IR ~/Public/
22 network-error.png network-offline.png network-transmit.png
cod4pc.txt network-idle.png network-receive.png network-transmit-receive.png

[jukeboxhero@Mothership ~]$ ls -lR ~/Public/
/home/jukeboxhero/Public/:
total 32
drwxrwxr-x 2 jukeboxhero jukeboxhero 4096 2009-05-24 08:32 22
-rwxrwxrwx 1 jukeboxhero jukeboxhero 907 2008-07-18 01:34 cod4pc.txt
-rw-r--r--. 1 root root 1270 2009-03-18 08:13 network-error.png
-rw-r--r--. 1 root root 989 2009-03-18 08:13 network-idle.png
-rw-r--r--. 1 root root 1143 2009-03-18 08:13 network-offline.png
-rw-r--r--. 1 root root 1120 2009-03-18 08:13 network-receive.png
-rw-r--r--. 1 root root 1134 2009-03-18 08:13 network-transmit.png
-rw-r--r--. 1 root root 1056 2009-03-18 08:13 network-transmit-receive.png

/home/jukeboxhero/Public/22:
total 28
-rw-r--r--. 1 root root 862 2009-03-18 08:13 network-error.png
-rw-r--r--. 1 root root 672 2009-03-18 08:13 network-idle.png
-rw-r--r--. 1 root root 811 2009-03-18 08:13 network-offline.png
-rw-r--r--. 1 root root 720 2009-03-18 08:13 network-receive.png
-rw-r--r--. 1 root root 720 2009-03-18 08:13 network-transmit.png
-rw-r--r--. 1 root root 689 2009-03-18 08:13 network-transmit-receive.png
-rw-r--r--. 1 root root 1537 2009-03-18 08:13 network-wireless-encrypted.png
[jukeboxhero@Mothership ~]$

Sergei Steshenko · 05-26-2009, 05:40 AM

Quote:

Originally Posted by Hitboxx

@Sergei,

So, you do need to find max file size in just one directory or recursively in that directory and all its subdirectories ?

And another question for you - have you thought about identifying files vs directories ? You listing shows both.

Hitboxx · 05-26-2009, 05:44 AM

I think recursively as -R is implied.

I don't think directories matter for identification, only files should suffice, and I don't know how to manipulate the listing.

Sergei Steshenko · 05-26-2009, 05:50 AM

Quote:

Originally Posted by Hitboxx

I think recursively as -R is implied.

I don't think directories matter for identification, only files should suffice, and I don't know how to manipulate the listing.

For starters, try this:

Code:

find ~/Public -type f -exec ls -lt '{}' \;

and publish the result here.

The next suggestion: read 'man cut' and think about the

Code:

' '

delimiter.

Hitboxx · 05-26-2009, 05:58 AM

[jukeboxhero@Mothership b]$ find ~/Public/ -type f -exec ls -lt '{}' \;

Quote:

-rwxrwxrwx 1 jukeboxhero jukeboxhero 907 2008-07-18 01:34 /home/jukeboxhero/Public/cod4pc.txt
-rw-r--r--. 1 root root 1120 2009-03-18 08:13 /home/jukeboxhero/Public/network-receive.png
-rw-r--r--. 1 root root 1143 2009-03-18 08:13 /home/jukeboxhero/Public/network-offline.png
-rw-r--r--. 1 root root 1056 2009-03-18 08:13 /home/jukeboxhero/Public/network-transmit-receive.png
-rw-r--r--. 1 root root 1537 2009-03-18 08:13 /home/jukeboxhero/Public/22/network-wireless-encrypted.png
-rw-r--r--. 1 root root 720 2009-03-18 08:13 /home/jukeboxhero/Public/22/network-receive.png
-rw-r--r--. 1 root root 811 2009-03-18 08:13 /home/jukeboxhero/Public/22/network-offline.png
-rw-r--r--. 1 root root 689 2009-03-18 08:13 /home/jukeboxhero/Public/22/network-transmit-receive.png
-rw-r--r--. 1 root root 862 2009-03-18 08:13 /home/jukeboxhero/Public/22/network-error.png
-rw-r--r--. 1 root root 720 2009-03-18 08:13 /home/jukeboxhero/Public/22/network-transmit.png
-rw-r--r--. 1 root root 672 2009-03-18 08:13 /home/jukeboxhero/Public/22/network-idle.png
-rw-rw-r-- 1 jukeboxhero jukeboxhero 156 2009-05-25 16:30 /home/jukeboxhero/Public/.directory
-rw-r--r--. 1 root root 1270 2009-03-18 08:13 /home/jukeboxhero/Public/network-error.png
-rw-r--r--. 1 root root 1134 2009-03-18 08:13 /home/jukeboxhero/Public/network-transmit.png
-rw-r--r--. 1 root root 989 2009-03-18 08:13 /home/jukeboxhero/Public/network-idle.png

Sergei Steshenko · 05-26-2009, 06:03 AM

Quote:

Originally Posted by Hitboxx

[jukeboxhero@Mothership b]$ find ~/Public/ -type f -exec ls -lt '{}' \;

Nice - now we have just files, and the listing is actually very regular - the same number of columns if we consider ' ' (space) to be the delimiter.

So, the questions:

in what field (column) number do we have size ?
have you read 'man cut' ?

Again, column/field should not be understood in plain text manner, but as number of entity where entities are groups of non-space characters.

Hitboxx · 05-26-2009, 06:11 AM

Yeah read man cut, but didn't get deep enough.

For the size, I think its the 5th column from the left.

Sergei Steshenko · 05-26-2009, 06:15 AM

Quote:

Originally Posted by Hitboxx

Yeah read man cut, but didn't get deep enough.

For the size, I think its the 5th column from the left.

Yes, it's the fifth element, or field in 'cut' terms.

So, your next step is piping the output of already tried 'find' command into 'cut' in order to get the 5-th field, using space as delimiter.

Make na effort, it is easy.

Start from single line piped into 'cut', i.e.

Code:

echo "-rw-r--r--. 1 root root 1134 2009-03-18 08:13 network-transmit.png" | cut YOUR_ARGUMENTS_HERE

- replace YOUR_ARGUMENTS_HERE with the needed arguments based on your understanding of 'man cut'. It is easy. I.e. you basically need the simplest 'cut' usage case.

colucix · 05-26-2009, 06:19 AM

Joining the advices from Sergej and Guttorm, with some modifications:

Code:

find ~/Public -type f -print0 | xargs -0 ls -lS | head -1 | cut YOUR_ARGUMENTS_HERE

See man find, man xargs, man ls, man head, man cut for details.

Sergei Steshenko · 05-26-2009, 06:26 AM

Quote:

Originally Posted by colucix

Joining the advices from Sergej and Guttorm, with some modifications:

Code:

find ~/Public -type f -print0 | xargs -0 ls -lS | head -1 | cut YOUR_ARGUMENTS_HERE

See man find, man xargs, man ls, man head, man cut for details.

And for what an extra level of complexity with 'head -1' ? You will need one more sorting anyway.

And I have tried your command, and it doesn't work.