root/src/lib9/fmt/vsmprint.c

DEFINITIONS

1. fmtStrFlush
2. fmtstrinit
3. vsmprint

/*
 * The authors of this software are Rob Pike and Ken Thompson,
 * with contributions from Mike Burrows and Sean Dorward.
 *
 *     Copyright (c) 2002-2006 by Lucent Technologies.
 *     Portions Copyright (c) 2004 Google Inc.
 * 
 * Permission to use, copy, modify, and distribute this software for any
 * purpose without fee is hereby granted, provided that this entire notice
 * is included in all copies of any software which is or includes a copy
 * or modification of this software and in all copies of the supporting
 * documentation for such software.
 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTY.  IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES 
 * NOR GOOGLE INC MAKE ANY REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING 
 * THE MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
 */

#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 = (char*)f->start;
        f->start = realloc(s, (size_t)n);
        if(f->start == nil){
                f->farg = nil;
                f->to = nil;
                f->stop = nil;
                free(s);
                return 0;
        }
        f->farg = (void*)(uintptr)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((size_t)n);
        if(f->start == nil)
                return -1;
        f->to = f->start;
        f->stop = (char*)f->start + n - 1;
        f->flush = fmtStrFlush;
        f->farg = (void*)(uintptr)n;
        f->nfmt = 0;
        fmtlocaleinit(f, nil, nil, nil);
        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;
        VA_COPY(f.args,args);
        n = dofmt(&f, fmt);
        VA_END(f.args);
        if(n < 0){
                free(f.start);
                return nil;
        }
        return fmtstrflush(&f);
}