I went through quite a few threads and didn't find anything on this. I also looked on other sites and couldn't turn up an answer.

For completeness sake, I'm working off of solaris 10 in the korn shell environment.

I wrote a script for a buddy to help him out with the following issue.

He has a directory of files, here is an example of one of the files

verylongstringofmixedcharacters==-=-23480732.pdf

He wanted to write a script to remove everything from the "==-=-" and the numbers after it so the file would look like the following:

verylongstringofmixedcharacters.pdf

Utilizing the "cut -d= -f1" command and the "cut -d. -f2" command, I was able to pull off the "verylongstringofmixedcharacters" and the "pdf" part. I then set a new variable name to using the following line:
fileparts=`echo $filepart1'.'$filepart2`

That's not the whole script, but that's the piece where the new filename is created to what he desired. When I finished it and sent it off, he gave me the bad news that sometimes within the verylongstringofmixedcharacters there can be found an = sign. So it might be "verylong=stringof=mixedcharacters", thereby not allowing my first delimiter of = to work. My question to you all is the following:

Is there a way to have a multicharacter delimiter with cut? Meaning, could it be, "cut -d==-=- -f1"? I've tried it the following ways and I received an invalid delimiter messages:

cut -d==-=- -f1
cut -d"==-=-" -f1
cut -d'==-=-' -f1
cut -d "==-=-" -f1
cut -d '==-=-' -f1

I'm thinking I'll have to use a sed command of sorts to fix this. I'm looking into sed one liners that might help after I post this, but I figure I stimulate your brains with it. Thanks in advance for your help.
~Ryan