53 lines
1,009 B
C
53 lines
1,009 B
C
#include <stdio.h>
|
|
#include <printf.h>
|
|
#include <stdarg.h>
|
|
|
|
/*@group*/
|
|
typedef struct
|
|
{
|
|
char *name;
|
|
} Widget;
|
|
/*@end group*/
|
|
|
|
int
|
|
print_widget (FILE *stream, const struct printf_info *info, va_list *app)
|
|
{
|
|
Widget *w;
|
|
char *buffer;
|
|
int len;
|
|
|
|
/* Format the output into a string. */
|
|
w = va_arg (*app, Widget *);
|
|
len = asprintf (&buffer, "<Widget %p: %s>", w, w->name);
|
|
if (len == -1)
|
|
return -1;
|
|
|
|
/* Pad to the minimum field width and print to the stream. */
|
|
len = fprintf (stream, "%*s",
|
|
(info->left ? - info->width : info->width),
|
|
buffer);
|
|
|
|
/* Clean up and return. */
|
|
free (buffer);
|
|
return len;
|
|
}
|
|
|
|
|
|
int
|
|
main (void)
|
|
{
|
|
/* Make a widget to print. */
|
|
Widget mywidget;
|
|
mywidget.name = "mywidget";
|
|
|
|
/* Register the print function for widgets. */
|
|
register_printf_function ('W', print_widget, NULL); /* No arginfo. */
|
|
|
|
/* Now print the widget. */
|
|
printf ("|%W|\n", &mywidget);
|
|
printf ("|%35W|\n", &mywidget);
|
|
printf ("|%-35W|\n", &mywidget);
|
|
|
|
return 0;
|
|
}
|