diff --git a/lib/libstand/printf.c b/lib/libstand/printf.c index 977c02638833..1a86e93d9258 100644 --- a/lib/libstand/printf.c +++ b/lib/libstand/printf.c @@ -56,8 +56,16 @@ __FBSDID("$FreeBSD$"); #define MAXNBUF (sizeof(intmax_t) * CHAR_BIT + 1) +typedef void (kvprintf_fn_t)(int, void *); + static char *ksprintn (char *buf, uintmax_t num, int base, int *len, int upper); -static int kvprintf(char const *fmt, void (*func)(int), void *arg, int radix, va_list ap); +static int kvprintf(char const *fmt, kvprintf_fn_t *func, void *arg, int radix, va_list ap); + +static void +putchar_wrapper(int cc, void *arg) +{ + putchar(cc); +} int printf(const char *fmt, ...) @@ -66,7 +74,7 @@ printf(const char *fmt, ...) int retval; va_start(ap, fmt); - retval = kvprintf(fmt, putchar, NULL, 10, ap); + retval = kvprintf(fmt, putchar_wrapper, NULL, 10, ap); va_end(ap); return retval; } @@ -74,8 +82,7 @@ printf(const char *fmt, ...) void vprintf(const char *fmt, va_list ap) { - - kvprintf(fmt, putchar, NULL, 10, ap); + kvprintf(fmt, putchar_wrapper, NULL, 10, ap); } int @@ -91,6 +98,46 @@ sprintf(char *buf, const char *cfmt, ...) return retval; } +struct print_buf { + char *buf; + size_t size; +}; + +static void +snprint_func(int ch, void *arg) +{ + struct print_buf *pbuf = arg; + + if (pbuf->size < 2) { + /* + * Reserve last buffer position for the terminating + * character: + */ + return; + } + *(pbuf->buf)++ = ch; + pbuf->size--; +} + +int +snprintf(char *buf, size_t size, const char *cfmt, ...) +{ + int retval; + va_list ap; + struct print_buf arg; + + arg.buf = buf; + arg.size = size; + + va_start(ap, cfmt); + retval = kvprintf(cfmt, &snprint_func, &arg, 10, ap); + va_end(ap); + + if (arg.size >= 1) + *(arg.buf)++ = 0; + return retval; +} + void vsprintf(char *buf, const char *cfmt, va_list ap) { @@ -149,9 +196,9 @@ ksprintn(char *nbuf, uintmax_t num, int base, int *lenp, int upper) * ("%*D", len, ptr, " " -> XX XX XX XX ... */ static int -kvprintf(char const *fmt, void (*func)(int), void *arg, int radix, va_list ap) +kvprintf(char const *fmt, kvprintf_fn_t *func, void *arg, int radix, va_list ap) { -#define PCHAR(c) {int cc=(c); if (func) (*func)(cc); else *d++ = cc; retval++; } +#define PCHAR(c) {int cc=(c); if (func) (*func)(cc, arg); else *d++ = cc; retval++; } char nbuf[MAXNBUF]; char *d; const char *p, *percent, *q; diff --git a/lib/libstand/stand.h b/lib/libstand/stand.h index 2a1e9a993276..28087226a526 100644 --- a/lib/libstand/stand.h +++ b/lib/libstand/stand.h @@ -238,6 +238,7 @@ extern void mallocstats(void); extern int printf(const char *fmt, ...) __printflike(1, 2); extern void vprintf(const char *fmt, __va_list); extern int sprintf(char *buf, const char *cfmt, ...) __printflike(2, 3); +extern int snprintf(char *buf, size_t size, const char *cfmt, ...) __printflike(3, 4); extern void vsprintf(char *buf, const char *cfmt, __va_list); extern void twiddle(void);