Shell Programming and Scripting

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

You could set the Field Separator pattern in awk...

Code:

$ echo "verylongstringofmixedcharacters==-=-23480732.pdf"|awk 'BEGIN{FS="==-=-"}{print $1}'
verylongstringofmixedcharacters

You can even use multiple patterns...

Code:

$ echo "verylongstringofmixedcharacters==-=-23480732.pdf"|awk 'BEGIN{FS="(==-=-|\\.)";OFS="."}{print $1,$3}'
verylongstringofmixedcharacters.pdf

Or use sed...

Code:

$ echo "verylongstringofmixedcharacters==-=-23480732.pdf"|sed 's/\(.*\)==-=-.*\(\.pdf\)/\1\2/'
verylongstringofmixedcharacters.pdf

Code:

for file in *==-=-* ; do
    mv "$file" "${file%%==-=-*}.${file##*.}"
done

Ygor, I'm very new to sed and have only started to realize the true potential of it. I hate to be a bother, but if you could explain how your command is interpreted, it would be greatly helpful:

sed 's/\(.*\)==-=-.*\(\.pdf\)/\1\2/'

Since posting the original post I was using the following string:

sed 's/==-=-*//g'

For some reason it doesn't recognize the * as the wildcard character, even if I put a \ before it.

Reborg, I'd like to note that not all of the files have a .pdf extension, there might be .xls or .txt or other varying types of files. I used pdf just as an example, sorry if I mislead folks there.

Thank you in advance for your help!

see edit above.

For sed, you are dealing with an RE ( regular expression ) , not a GLOB pattern.

* in RE means 0 or more of the preceding character, not any number of any character as in a glob pattern. The single character wildcard in RE is ., therefore ".*" corresponds ( more or less ) with * in a glob pattern.

Search:

Code:

\(     start of first bracketed pattern
.*     any number of characters
\)     end of first bracketed pattern
==-=-  literal
.*     any number of characters
\(     start of second bracketed pattern
\.pdf  literal ("." is escaped to prevent its special meaning)
\)     end of second bracketed pattern

Replacement:

Code:

\1     first bracketed pattern
\2     second bracketed pattern

Thank you, I see now how it all fits together. Seeing the actual meaning behind what each piece is doing helps out quite a bit! As stated in the replies above, .pdf isn't necessarily the only file extension this would have to look for. I made a slight change to it and it seems to work:

sed 's/\(.*\)==-=-.*\(\...\)/\1\2/'

I took pdf and replaced it with ..., the only question is, what if there is a greater number than 3 for the file extension? I don't think ... will work then, since it's going for literally 3 characters for that second part. What would be the correct expression to use to say "Any amount of character" and not just 3? Thanks again, both of ye for your input and help!