ref: c8a7747659c6b8aa4989cfcccf518cbe18d9182d
dir: /sys/src/libc/fmt/vfprint.c/
#include <u.h> #include <libc.h> #include "fmtdef.h" /* * generic routine for flushing a formatting buffer * to a file descriptor */ int _fmtFdFlush(Fmt *f) { int n; n = (char*)f->to - (char*)f->start; if(n && write((int)(uintptr)f->farg, f->start, n) != n) return 0; f->to = f->start; return 1; } int vfprint(int fd, char *fmt, va_list args) { Fmt f; char buf[256]; int n; fmtfdinit(&f, fd, buf, sizeof(buf)); f.args = args; n = dofmt(&f, fmt); if(n > 0 && _fmtFdFlush(&f) == 0) return -1; return n; }