typedef void (*configfn)(const char *name, const char *value);
typedef void (*filepair_fn)(struct diff_filepair *pair);
typedef void (*linediff_fn)(char *line, int len);
typedef void (*configfn)(const char *name, const char *value);
typedef void (*filepair_fn)(struct diff_filepair *pair);
typedef void (*linediff_fn)(char *line, int len);