Coding philosophy

Most of the code was kept in as few files as possible, with the smallest possible number of parameters. Whenever more parameters are required, it should always be possible to give NULL or 0 as values to get a default behavior.

For example, the read_line_alloc takes many parameters:

int read_line_alloc(void* in, DataSourceType in_type, char** line,
			int* sz_line, int i0, char from, char to, int keep_fromto,
			char interest, int* interest_count);

The only really mandatory parameters are obviously in and line. All others can be set to NULL, 0 or '\0':
Calling read_line_alloc(f, DATA_SOURCE_FILE, &line, NULL, 0, 0, 0, 0, 0, NULL); will read bytes from f into line starting from current position in f until a newline character (or end-of-file) has been reached. line will be allocated but its size will not be returned (only the number of characters read). No special character will be counted during file reading.

So, if you are not too sure what to put as a parameter, just zero it, it should be fine! :)