line-range.h

   1 #ifndef LINE_RANGE_H
   2 #define LINE_RANGE_H
   3
   4 /*
   5  * Parse one item in an -L begin,end option w.r.t. the notional file
   6  * object 'cb_data' consisting of 'lines' lines.
   7  *
   8  * The 'nth_line_cb' callback is used to determine the start of the
   9  * line 'lno' inside the 'cb_data'.  The caller is expected to already
  10  * have a suitable map at hand to make this a constant-time lookup.
  11  *
  12  * Returns 0 in case of success and -1 if there was an error.  The
  13  * actual range is stored in *begin and *end.  The counting starts
  14  * at 1!  In case of error, the caller should show usage message.
  15  */
  16
  17 typedef const char *(*nth_line_fn_t)(void *data, long lno);
  18
  19 extern int parse_range_arg(const char *arg,
  20                            nth_line_fn_t nth_line_cb,
  21                            void *cb_data, long lines,
  22                            long *begin, long *end);
  23
  24 /*
  25  * Scan past a range argument that could be parsed by
  26  * 'parse_range_arg', to help the caller determine the start of the
  27  * filename in '-L n,m:file' syntax.
  28  *
  29  * Returns a pointer to the first character after the 'n,m' part, or
  30  * NULL in case the argument is obviously malformed.
  31  */
  32
  33 extern const char *skip_range_arg(const char *arg);
  34
  35 #endif /* LINE_RANGE_H */