t9300: factor out portable "head -c" replacement

diff --git a/line-range.h b/line-range.h
index 830f25b501df5aa5960d1c654aa767335f7f506b..83ba3c25e88a4601dc17ce01dc57dfbc33c05b2e 100644 (file)
--- a/line-range.h
+++ b/line-range.h
@@ -9,6 +9,9 @@
  * line 'lno' inside the 'cb_data'.  The caller is expected to already
  * have a suitable map at hand to make this a constant-time lookup.
  *
+ * 'anchor' is the 1-based line at which relative range specifications
+ * should be anchored. Absolute ranges are unaffected by this value.
+ *
  * Returns 0 in case of success and -1 if there was an error.  The
  * actual range is stored in *begin and *end.  The counting starts
  * at 1!  In case of error, the caller should show usage message.
@@ -18,7 +21,19 @@ typedef const char *(*nth_line_fn_t)(void *data, long lno);
 
 extern int parse_range_arg(const char *arg,
                           nth_line_fn_t nth_line_cb,
-                          void *cb_data, long lines,
-                          long *begin, long *end);
+                          void *cb_data, long lines, long anchor,
+                          long *begin, long *end,
+                          const char *path);
+
+/*
+ * Scan past a range argument that could be parsed by
+ * 'parse_range_arg', to help the caller determine the start of the
+ * filename in '-L n,m:file' syntax.
+ *
+ * Returns a pointer to the first character after the 'n,m' part, or
+ * NULL in case the argument is obviously malformed.
+ */
+
+extern const char *skip_range_arg(const char *arg);
 
 #endif /* LINE_RANGE_H */