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39
40#include "qplatformdefs.h"
41
42#include "qbytearray.h"
43#include "qstring.h"
44
45#include "string.h"
46
47QT_BEGIN_NAMESPACE
48
49#if !defined(QT_VSNPRINTF) || defined(Q_CLANG_QDOC)
50
51/*!
52 \relates QByteArray
53
54 A portable \c vsnprintf() function. Will call \c ::vsnprintf(), \c
55 ::_vsnprintf(), or \c ::vsnprintf_s depending on the system, or
56 fall back to an internal version.
57
58 \a fmt is the \c printf() format string. The result is put into
59 \a str, which is a buffer of at least \a n bytes.
60
61 The caller is responsible to call \c va_end() on \a ap.
62
63 \warning Since vsnprintf() shows different behavior on certain
64 platforms, you should not rely on the return value or on the fact
65 that you will always get a 0 terminated string back.
66
67 Ideally, you should never call this function but use QString::asprintf()
68 instead.
69
70 \sa qsnprintf(), QString::asprintf()
71*/
72
73int qvsnprintf(char *str, size_t n, const char *fmt, va_list ap)
74{
75 if (!str || !fmt)
76 return -1;
77
78 const QByteArray ba = QString::vasprintf(fmt, ap).toLocal8Bit();
79
80 if (n > 0) {
81 size_t blen = qMin(size_t(ba.length()), size_t(n - 1));
82 memcpy(str, ba.constData(), blen);
83 str[blen] = '\0'; // make sure str is always 0 terminated
84 }
85
86 return ba.length();
87}
88
89#else
90
91QT_BEGIN_INCLUDE_NAMESPACE
92#include <stdio.h>
93QT_END_INCLUDE_NAMESPACE
94
95int qvsnprintf(char *str, size_t n, const char *fmt, va_list ap)
96{
97 return QT_VSNPRINTF(s: str, maxlen: n, format: fmt, arg: ap);
98}
99
100#endif
101
102/*!
103 \target bytearray-qsnprintf
104 \relates QByteArray
105
106 A portable snprintf() function, calls qvsnprintf.
107
108 \a fmt is the \c printf() format string. The result is put into
109 \a str, which is a buffer of at least \a n bytes.
110
111 \warning Call this function only when you know what you are doing
112 since it shows different behavior on certain platforms.
113 Use QString::asprintf() to format a string instead.
114
115 \sa qvsnprintf(), QString::asprintf()
116*/
117
118int qsnprintf(char *str, size_t n, const char *fmt, ...)
119{
120 va_list ap;
121 va_start(ap, fmt);
122
123 int ret = qvsnprintf(str, n, fmt, ap);
124 va_end(ap);
125
126 return ret;
127}
128
129QT_END_NAMESPACE
130

source code of qtbase/src/corelib/text/qvsnprintf.cpp