xref: /plan9/sys/src/cmd/unix/drawterm/libc/runevsmprint.c (revision 0d601874851962e88c6c60fdd2e637bba04e13c2)
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 #include <u.h>
15 #include <libc.h>
16 #include "fmtdef.h"
17 
18 static int
19 runeFmtStrFlush(Fmt *f)
20 {
21 	Rune *s;
22 	int n;
23 
24 	if(f->start == nil)
25 		return 0;
26 	n = (uintptr)f->farg;
27 	n *= 2;
28 	s = (Rune*)f->start;
29 	f->start = realloc(s, sizeof(Rune)*n);
30 	if(f->start == nil){
31 		f->farg = nil;
32 		f->to = nil;
33 		f->stop = nil;
34 		free(s);
35 		return 0;
36 	}
37 	f->farg = (void*)(uintptr)n;
38 	f->to = (Rune*)f->start + ((Rune*)f->to - s);
39 	f->stop = (Rune*)f->start + n - 1;
40 	return 1;
41 }
42 
43 int
44 runefmtstrinit(Fmt *f)
45 {
46 	int n;
47 
48 	memset(f, 0, sizeof *f);
49 	f->runes = 1;
50 	n = 32;
51 	f->start = malloc(sizeof(Rune)*n);
52 	if(f->start == nil)
53 		return -1;
54 	f->to = f->start;
55 	f->stop = (Rune*)f->start + n - 1;
56 	f->flush = runeFmtStrFlush;
57 	f->farg = (void*)(uintptr)n;
58 	f->nfmt = 0;
59 	return 0;
60 }
61 
62 /*
63  * print into an allocated string buffer
64  */
65 Rune*
66 runevsmprint(char *fmt, va_list args)
67 {
68 	Fmt f;
69 	int n;
70 
71 	if(runefmtstrinit(&f) < 0)
72 		return nil;
73 	VA_COPY(f.args,args);
74 	n = dofmt(&f, fmt);
75 	VA_END(f.args);
76 	if(f.start == nil)
77 		return nil;
78 	if(n < 0){
79 		free(f.start);
80 		return nil;
81 	}
82 	*(Rune*)f.to = '\0';
83 	return (Rune*)f.start;
84 }
85