1 /*
2  * The authors of this software are Rob Pike and Ken Thompson.
3  *              Copyright (c) 2002 by Lucent Technologies.
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose without fee is hereby granted, provided that this entire notice
6  * is included in all copies of any software which is or includes a copy
7  * or modification of this software and in all copies of the supporting
8  * documentation for such software.
9  * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
10  * WARRANTY.  IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE
11  * ANY REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
12  * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
13  */
14 /*
15  * Plan 9 port version must include libc.h in order to 
16  * get Plan 9 debugging malloc, which sometimes returns
17  * different pointers than the standard malloc. 
18  */
19 #ifdef PLAN9PORT
20 #include <u.h>
21 #include <libc.h>
22 #include "fmtdef.h"
23 #else
24 #include <stdlib.h>
25 #include <string.h>
26 #include "plan9.h"
27 #include "fmt.h"
28 #include "fmtdef.h"
29 #endif
30 
31 static int
32 fmtStrFlush(Fmt *f)
33 {
34 	char *s;
35 	int n;
36 
37 	if(f->start == nil)
38 		return 0;
39 	n = (int)f->farg;
40 	n *= 2;
41 	s = (char*)f->start;
42 	f->start = realloc(s, n);
43 	if(f->start == nil){
44 		f->farg = nil;
45 		f->to = nil;
46 		f->stop = nil;
47 		free(s);
48 		return 0;
49 	}
50 	f->farg = (void*)n;
51 	f->to = (char*)f->start + ((char*)f->to - s);
52 	f->stop = (char*)f->start + n - 1;
53 	return 1;
54 }
55 
56 int
57 fmtstrinit(Fmt *f)
58 {
59 	int n;
60 
61 	memset(f, 0, sizeof *f);
62 	f->runes = 0;
63 	n = 32;
64 	f->start = malloc(n);
65 	if(f->start == nil)
66 		return -1;
67 	f->to = f->start;
68 	f->stop = (char*)f->start + n - 1;
69 	f->flush = fmtStrFlush;
70 	f->farg = (void*)n;
71 	f->nfmt = 0;
72 	return 0;
73 }
74 
75 /*
76  * print into an allocated string buffer
77  */
78 char*
79 vsmprint(char *fmt, va_list args)
80 {
81 	Fmt f;
82 	int n;
83 
84 	if(fmtstrinit(&f) < 0)
85 		return nil;
86 	VA_COPY(f.args,args);
87 	n = dofmt(&f, fmt);
88 	VA_END(f.args);
89 	if(n < 0){
90 		free(f.start);
91 		return nil;
92 	}
93 	return fmtstrflush(&f);
94 }