ref: 1213937bfa73b0303bd50faafcc99bf759716b4e
dir: /lib/c/src/vfprintf.c/
#include <stdarg.h> #include <stdio.h> #undef vfprintf static int printn2(FILE * restrict fp, unsigned n, int base) { unsigned t; int cnt = 0; static char digits[] = "0123456789ABCDEF"; if ((t = n / base) != 0) cnt += printn2(fp, t, base); putc(digits[n % base], fp); return cnt + 1; } static int printn(FILE * restrict fp, int n, int b, int sign) { int cnt = 0; if (sign && n < 0) { n = -n; putc('-', fp); ++cnt; } cnt += printn2(fp, n, b); return cnt; } int vfprintf(FILE * restrict fp, const char *fmt, va_list va) { int c, base, sign, cnt = 0; char *s; while ((c = *fmt++) != '\0') { if (c == '%') { sign = 0; switch (*fmt++) { case '%': c = '%'; break; case 'c': c = va_arg(va, int); break; case 'o': base = 8; goto numeric; case 'd': sign = 1; base = 10; goto numeric; case 'x': base = 16; numeric: c = va_arg(va, int); cnt += printn(fp, c, base, sign); continue; case 's': s = va_arg(va, char *); while ((c = *s++) != '\0') putc(c, fp); default: continue; } } putc(c, fp); ++cnt; } return cnt; }