I want to change style of table of contents which is given by \tableofcontents, (say I do not want that much space between lines and some I want the subsections to be listed in one line).
How can I do that?
(So far I can only edit toc-file by hands, which is not a good solution.)
The short answer for almost all TOC, LOF, LOT, etc. customisations is first to see if you can achieve what you want using the tocloft package. Nine times out of ten, you'll be able to.
To complement @Geoffrey's answer, note also that if you use the memoir class, the tocloft is included (reproduced ?) and you can use the same functionalities. The memoir manual has a complete chapter about the customization of the ToC, LoF, LoT.
