ref: eb1be5b4df533c4e5100296fb042e274da435b5b
dir: /sys/src/libc/fmt/vsmprint.c/
#include <u.h> #include <libc.h> #include "fmtdef.h" static int fmtStrFlush(Fmt *f) { char *s; int n; if(f->start == nil) return 0; n = (int)(uintptr)f->farg; n *= 2; s = f->start; f->start = realloc(s, n); if(f->start == nil){ f->farg = nil; f->to = nil; f->stop = nil; free(s); return 0; } f->farg = (void*)n; f->to = (char*)f->start + ((char*)f->to - s); f->stop = (char*)f->start + n - 1; return 1; } int fmtstrinit(Fmt *f) { int n; memset(f, 0, sizeof *f); f->runes = 0; n = 32; f->start = malloc(n); if(f->start == nil) return -1; f->to = f->start; f->stop = (char*)f->start + n - 1; f->flush = fmtStrFlush; f->farg = (void*)n; f->nfmt = 0; return 0; } /* * print into an allocated string buffer */ char* vsmprint(char *fmt, va_list args) { Fmt f; int n; if(fmtstrinit(&f) < 0) return nil; f.args = args; n = dofmt(&f, fmt); if(f.start == nil) return nil; if(n < 0){ free(f.start); return nil; } *(char*)f.to = '\0'; return f.start; }