Shell Programming and Scripting

I'm trying to customize my environment at work in a Unix system.
So I'm starting with the ls command...

I'd like to make it run as the Linux ls...
Even in color, if possible...

My first problem is to make the file listing brake in columns...
In fact, the actual ls from Unix does this, but I'm trying to make my own ls command...

For now I've coded the following:
______________________________________________
#!/bin/ksh

COL_NUM=0

LINE_NUM=`ls | wc -w | tr -d" "`

ls -lF | tr -s " " | cut -d" " -f9 | sort -d |
while read -r FIELD
do
if [ `expr "$COL_NUM" % 5` - ne 0 ]; then
echo "$FIELD\t\c"
else
COL_NUM=0
echo "\n$FIELD\t\c"
fi
COL_NUM=`expr "$COL_NUM" + 1`
done

echo ""
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I wonder how the ls does this...

And, further, I'd like to display the files like the Linux does - each type of file has its own colour.

How do I print in colour in shell ?

Thanks in advance,
=== 435 Gavea ===

Hi,
You are configuring ls using ls :O
the script you have below is using ls twice to show you the output of ls once.
I think this will affect the performance of your command badly. If one has to try it on a huge list of files, it will take long time, for example even just ls in /tmp on my system at work place takes about 4-5 seconds to start displaying the output.
I think performance is important. Probably you can write the ls program yourself and then withing it try using the colors.
or if you still want to stick to the script, then I would suggest you to take the output from the first ls in some variable array.

as for the colours effect, check google for lscolors. Besides what unix are you using at your work place. The emulator you are using, does it support the colors.
In your script you can check the file type using "test" and then decide what color you want to display the file in. do look for man help. It will tell you how to check the file type
e.g (in ksh} to display files of type "file" in bold

test -d filename
if [ $? -eq 0 ]
then
echo "\033[1m $filename \033[0m"
fi

you can use case instead of if

returns 0 if filename is a directory

oops lotsa stuff
hope it helps

Thanks, I'll take a look at what you've suggested !

yea running ls on a dir 2x would be slow, but running if [ -d filename ] on every file in that dir would be real fast.

you could do a ls -l regardless of what the script is called with to a temp dir then go through each line of the file and if it starts "l" color it like a link, "b/c" color it like a block/char, "d" like a dir, and even some file type coloring with or if its executable make it green.

Maybe call it ll or something.

Code:

ls -l $1 > temp
while read LINE
do
  TYPE=$(echo $LINE|cut -b1)
  case $TYPE in
           d) echo "\033[1;34m$LINE\033[0m" ;;
            l) echo "\033[1;36m$LINE\033[0m" ;;
      [b,c]) echo "\033[40;33m$LINE\033[0m" ;;
           s) echo "\033[0;31m$LINE\033[0m" ;;
           -) if [[ $(echo $LINE|cut -b4) = "x" || \
                    $(echo $LINE|cut -b7) = "x" || \
                    $(echo $LINE|cut -b10) = "x" ]]
              then
                echo "\033[32m$LINE\033[0m"
              else
                echo "\033[0m$LINE"
              fi ;;
           *) echo "\033[0m$LINE" ;;
  esac
done < temp