flex: Accessor Methods
19.4.5 Accessing Variables with Reentrant Scanners
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Accessor methods (get/set functions) provide access to common 'flex'
variables.
Many scanners that you build will be part of a larger project.
Portions of your project will need access to 'flex' values, such as
'yytext'. In a non-reentrant scanner, these values are global, so there
is no problem accessing them. However, in a reentrant scanner, there
are no global 'flex' values. You can not access them directly.
Instead, you must access 'flex' values using accessor methods (get/set
functions). Each accessor method is named 'yyget_NAME' or 'yyset_NAME',
where 'NAME' is the name of the 'flex' variable you want. For example:
/* Set the last character of yytext to NULL. */
void chop ( yyscan_t scanner )
{
int len = yyget_leng( scanner );
yyget_text( scanner )[len - 1] = '\0';
}
The above code may be called from within an action like this:
%%
.+\n { chop( yyscanner );}
You may find that '%option header-file' is particularly useful for
generating prototypes of all the accessor functions. ⇒
option-header.
Info Catalog
flex: Init and Destroy Functions
flex: Reentrant Detail
flex: Extra Data