Shell Programming and Scripting

I need some help with a unix script to mv image files to subdirectories based on the 1st character of the filename. See example below...

/images/main

1191.jpg
9999.jpg
A101.jpg
A102.jpg
B201.jpg
c333.jpg
...
Z999.jpg

I would like to move to the following:

/images/main/1/1191.jpg
/images/main/9/9999.jpg
/images/main/a/A101.jpg
/images/main/a/A102.jpg
/images/main/b/B201.jpg
/images/main/c/c333.jpg
...
/images/main/z/Z999.jpg

Any help would be greatly appreciated.

Thanks!

Another one:

Code:

#!/bin/sh

dir="/images/main"

for file in *.jpg
do
  sd="$dir"/`echo "$file"|cut -c 1`
  mkdir -p "$sd"
  mv "$file" "$sd"
done

Regards

franklin52 script is very good but needs a tweak to change the directory to lowercase.
tr "[A-Z]" "a-z"

BTW. Don't use this syntax because it is upset by single character filenames!
tr [A-Z] [a-z]

If you have a very large number of files (or the filenames contain space characters) the script will need some work to generate the list of files in a pipe without decending the directory tree. Depends on which unix and which version of "find" you have.

Worked great. Thanks for your help!

I know he already has his answer . . . but I see a lot of answers on here
that are overly complicated. The ksh itself has much of the functionality
of cut, awk and sed. For example:


# This creates a variable that is only 1 character-wide, left-justified,upper-case
typeset -u -L1 first_letter

cd images/main

/bin/ls *.jpg |
while read file ; do

first_letter=$file

mkdir $first_letter
/bin/mv $file $first_letter

done

This script has the added feature of being a single process.
Therefore, if it mattered, which it probably doesn't nowadays,
it would be the fastest way performance-wise to do this.

Worked great the 1st time, but now when I try add more files to the directory and re-run it just hangs. Is there an issue because the directory ($dir) has already been created? If so, how do I modify to check first to see if $dir exists?

You can run it like so:

ksh -xvf script_file 2>&1 | more

And see exactly where it's getting hung up.

Other answer to your question:

if [ ! -d $dir ]; then
mkdir $dir
fi