The Go Programming Language

Text file src/lib9/fmt/vsmprint.c

     1	/*
     2	 * The authors of this software are Rob Pike and Ken Thompson,
     3	 * with contributions from Mike Burrows and Sean Dorward.
     4	 *
     5	 *     Copyright (c) 2002-2006 by Lucent Technologies.
     6	 *     Portions Copyright (c) 2004 Google Inc.
     7	 * 
     8	 * Permission to use, copy, modify, and distribute this software for any
     9	 * purpose without fee is hereby granted, provided that this entire notice
    10	 * is included in all copies of any software which is or includes a copy
    11	 * or modification of this software and in all copies of the supporting
    12	 * documentation for such software.
    13	 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
    14	 * WARRANTY.  IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES 
    15	 * NOR GOOGLE INC MAKE ANY REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING 
    16	 * THE MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
    17	 */
    18	
    19	#include <u.h>
    20	#include <libc.h>
    21	#include "fmtdef.h"
    22	
    23	static int
    24	fmtStrFlush(Fmt *f)
    25	{
    26		char *s;
    27		int n;
    28	
    29		if(f->start == nil)
    30			return 0;
    31		n = (uintptr)f->farg;
    32		n *= 2;
    33		s = (char*)f->start;
    34		f->start = realloc(s, n);
    35		if(f->start == nil){
    36			f->farg = nil;
    37			f->to = nil;
    38			f->stop = nil;
    39			free(s);
    40			return 0;
    41		}
    42		f->farg = (void*)(uintptr)n;
    43		f->to = (char*)f->start + ((char*)f->to - s);
    44		f->stop = (char*)f->start + n - 1;
    45		return 1;
    46	}
    47	
    48	int
    49	fmtstrinit(Fmt *f)
    50	{
    51		int n;
    52	
    53		memset(f, 0, sizeof *f);
    54		f->runes = 0;
    55		n = 32;
    56		f->start = malloc(n);
    57		if(f->start == nil)
    58			return -1;
    59		f->to = f->start;
    60		f->stop = (char*)f->start + n - 1;
    61		f->flush = fmtStrFlush;
    62		f->farg = (void*)(uintptr)n;
    63		f->nfmt = 0;
    64		fmtlocaleinit(f, nil, nil, nil);
    65		return 0;
    66	}
    67	
    68	/*
    69	 * print into an allocated string buffer
    70	 */
    71	char*
    72	vsmprint(char *fmt, va_list args)
    73	{
    74		Fmt f;
    75		int n;
    76	
    77		if(fmtstrinit(&f) < 0)
    78			return nil;
    79		VA_COPY(f.args,args);
    80		n = dofmt(&f, fmt);
    81		VA_END(f.args);
    82		if(n < 0){
    83			free(f.start);
    84			return nil;
    85		}
    86		return fmtstrflush(&f);
    87	}

release.r60.3. Except as noted, this content is licensed under a Creative Commons Attribution 3.0 License.