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  * 'anchor' is the 1-based line at which relative range specifications
  13  * should be anchored. Absolute ranges are unaffected by this value.
  14  *
  15  * Returns 0 in case of success and -1 if there was an error.  The
  16  * actual range is stored in *begin and *end.  The counting starts
  17  * at 1!  In case of error, the caller should show usage message.
  18  */
  19
  20 typedef const char *(*nth_line_fn_t)(void *data, long lno);
  21
  22 extern int parse_range_arg(const char *arg,
  23                            nth_line_fn_t nth_line_cb,
  24                            void *cb_data, long lines, long anchor,
  25                            long *begin, long *end,
  26                            const char *path);
  27
  28 /*
  29  * Scan past a range argument that could be parsed by
  30  * 'parse_range_arg', to help the caller determine the start of the
  31  * filename in '-L n,m:file' syntax.
  32  *
  33  * Returns a pointer to the first character after the 'n,m' part, or
  34  * NULL in case the argument is obviously malformed.
  35  */
  36
  37 extern const char *skip_range_arg(const char *arg);
  38
  39 #endif /* LINE_RANGE_H */