1 /* @(#)snprintf.c 1.16 19/10/19 Copyright 1985, 1996-2019 J. Schilling */
2 /*
3 * Copyright (c) 1985, 1996-2019 J. Schilling
4 */
5 /*
6 * The contents of this file are subject to the terms of the
7 * Common Development and Distribution License, Version 1.0 only
8 * (the "License"). You may not use this file except in compliance
9 * with the License.
10 *
11 * See the file CDDL.Schily.txt in this distribution for details.
12 * A copy of the CDDL is also available via the Internet at
13 * http://www.opensource.org/licenses/cddl1.txt
14 *
15 * When distributing Covered Code, include this CDDL HEADER in each
16 * file and include the License file CDDL.Schily.txt from this distribution.
17 */
18
19 #define snprintf __nothing__ /* prototype may be wrong (e.g. IRIX) */
20 #include <schily/mconfig.h>
21 #include <schily/unistd.h> /* include <sys/types.h> try to get size_t */
22 #include <schily/stdio.h> /* Try again for size_t */
23 #include <schily/stdlib.h> /* Try again for size_t */
24 #include <schily/varargs.h>
25 #include <schily/standard.h>
26 #include <schily/schily.h>
27 #undef snprintf
28
29 /*
30 * If PORT_ONLY is defined, snprintf() will only be compiled in if it is
31 * missing on the local platform. This is used by e.g. libschily.
32 */
33 #if !defined(HAVE_SNPRINTF) || !defined(PORT_ONLY)
34
35 EXPORT int snprintf __PR((char *, size_t maxcnt, const char *, ...));
36
37 typedef struct {
38 char *ptr;
39 int count;
40 } *BUF, _BUF;
41
42 #ifdef PROTOTYPES
43 static void
_cput(char c,void * l)44 _cput(char c, void *l)
45 #else
46 static void
47 _cput(c, l)
48 char c;
49 void *l;
50 #endif
51 {
52 register BUF bp = (BUF)l;
53
54 if (--bp->count > 0) {
55 *bp->ptr++ = c;
56 } else {
57 /*
58 * Make sure that there will never be a negative overflow.
59 */
60 bp->count++;
61 }
62 }
63
64 /* VARARGS2 */
65 #ifdef PROTOTYPES
66 EXPORT int
snprintf(char * buf,size_t maxcnt,const char * form,...)67 snprintf(char *buf, size_t maxcnt, const char *form, ...)
68 #else
69 EXPORT int
70 snprintf(buf, maxcnt, form, va_alist)
71 char *buf;
72 size_t maxcnt;
73 const char *form;
74 va_dcl
75 #endif
76 {
77 va_list args;
78 int cnt;
79 _BUF bb;
80
81 bb.ptr = buf;
82 bb.count = maxcnt;
83
84 #ifdef PROTOTYPES
85 va_start(args, form);
86 #else
87 va_start(args);
88 #endif
89 cnt = format(_cput, &bb, form, args);
90 va_end(args);
91 if (maxcnt > 0)
92 *(bb.ptr) = '\0';
93 if (bb.count < 0)
94 return (-1);
95
96 return (cnt);
97 }
98
99 #endif /* !defined(HAVE_SNPRINTF) || !defined(PORT_ONLY) */
100