Re: Variable Problem

[Jean Bréfort <jean brefort normalesup org>]

Le samedi 22 octobre 2005 �0:54 -0200, Wilton a �it :
> Hi, I'm starting to program in C/GTK+ and I have a problem with a 
> variable. Let me show the code and the error:
> 
> /*-- Global Variables --*/
>     char               query_string[256];
>     GtkWidget     *entry_sql;
> .
> .
> .
> 
> /*-- Do the instruction SQL --*/
>     sprintf(query_string, entry_sql); // Build the instruction SQL
>     res = PQexec(conn, query_string); // Send the SQL to the database
> 
> I need to pass the value in GtkWidget *entry_sql to the char 
> query_string[256] (a C variable), because when i compile it i receive 
> the following error:
> 
> [Warning] passing arg 2 of `sprintf' from incompatible pointer type
> 
> How can i solve this problem?

The use of sprintf is dangerous since you might have a buffer overflow
unless you are absolutely sure that the cpied string will never be that
big.
Anyway, assuming that entry_sql is a GtkEntry*, you can use :

char const *query_sql;
query_sql = gtk_entry_get_text (GTK_ENTRY (entry_sql));
...