+ char *temp;
+ char *out;
+
+ out = XMALLOC (char, strlen (in) + 1);
+
+ for (temp = out; *in; in++, out++)
+ if (*in == from)
+ *out = to;
+ else
+ *out = *in;
+ *out = 0;
+ return (temp);
+}
+
+/* Computes extensions from the grammar file extension. */
+static void
+compute_exts_from_gf (const char *ext)
+{
+ src_extension = tr (ext, 'y', 'c');
+ src_extension = tr (src_extension, 'Y', 'C');
+ header_extension = tr (ext, 'y', 'h');
+ header_extension = tr (header_extension, 'Y', 'H');
+}
+
+/* Computes extensions from the given c source file extension. */
+static void
+compute_exts_from_src (const char *ext)
+{
+ /* We use this function when the user specifies `-o' or `--output',
+ so the extenions must be computed unconditionally from the file name
+ given by this option. */
+ src_extension = xstrdup (ext);
+ header_extension = tr (ext, 'c', 'h');
+ header_extension = tr (header_extension, 'C', 'H');
+}
+
+
+/* Decompose FILENAME in four parts: *BASE, *TAB, and *EXT, the fourth
+ part, (the directory) is ranging from FILENAME to the char before
+ *BASE, so we don't need an additional parameter.
+
+ *EXT points to the last period in the basename, or NULL if none.
+
+ If there is no *EXT, *TAB is NULL. Otherwise, *TAB points to
+ `.tab' or `_tab' if present right before *EXT, or is NULL. *TAB
+ cannot be equal to *BASE.
+
+ None are allocated, they are simply pointers to parts of FILENAME.
+ Examples: