I suppose you are generally interested in learning to write shell scripts and not only to make the script going you are attempting to write. Therefore a little explanation why this (any other constructs similar to this) is a VERY BAD IDEA and you should never do it:

The "*" is interpreted by the shell first and replaced with its result: a list of all entries in the current directory. It is never a good idea to work with relative pathes inside a script. Execute a scriptin another path and this might mix up everything and render your system unusable.

Aside from this: say the directory contains 3 entries, "fileA", "fileB" and "fileC", then the line would be equivalent to:

Code:

FILES=fileA fileB fileC

The first problem is: not all entries in a directory have to be files. There are directories, links, FIFOs and more. Chances are your "convert" utility does not know how to handle them at all because it is built to work with a certain type of files and nothing else.

Another problem is: suppose you have lots of such files. A UNIX directory can easily handle millions of files (i have a few such systems). Imagine what your for-loop will do when it is presented this line:

Code:

for f in fileA fileB fileC ...many millions more... lastfile

The shell will simply give up and issue an "too many arguments"-error.

This is why such for-loops are never correct and always to be avoided. If you want to cycle through a list of files do it this way:

Code:

ls /path/to/dir | while read FILE ; do
     echo working on $FILE
done

If you want to modify your list you can either use shell-globs (*,?, ...) or text-filters to alter the list. For example, filter out every file with a number in the filename:

Code:

ls /path/to/dir | grep -v "[0-9]" | while read FILE ; do
     echo working on $FILE
done

Now, back to your problem, for which the find-command is the correct wa to do it.

I have written a little introduction about how find works.

Yes, because $f_small would be the content of a (non-existent) variable named "f_small". You can do whyt you want to do, but you need "variable expansion" for this, which is a bit complicated and probably not the first thing you want to learn.

For the sake of completeness, here you are:

Code:

f="example.jpg"

f_name="${f%.*}"
f_ext="${f##*.}"

echo "filename: $f_name   extension: $f_ext"

echo convert -thumbnail 235x "$f" "$f_name"_thumb."${f_ext}"

There are two ways to achieve this: put in multiple "-name"-clauses into the find-statement:

Code:

find /your/start/dir -type f \( -name "folder.jpg" -o -name "FOLDER.JPG" -o -name ....\) -exec ....

A second way is, when the names are related enough, to construct a single name-clause with a wildcard:

Code:

find /your/start/dir -type f -name "[Ff]older.jpg" -exec ....

Would find all files named "Folder.jpg" or "folder.jpg", for instance.

I hope this helps.

bakunin