summaryrefslogtreecommitdiffstats
path: root/src/corelib/doc/snippets/file/file.cpp
blob: d1244f4bf24a7a89fa86560b2edc609f3f47a0dd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause

#include <QFile>
#include <QTextStream>

static void process_line(const QByteArray &)
{
}

static void process_line(const QString &)
{
}

static void noStream_snippet()
{
//! [0]
    QFile file("in.txt");
    if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
        return;

    while (!file.atEnd()) {
        QByteArray line = file.readLine();
        process_line(line);
    }
//! [0]
}

static void readTextStream_snippet()
{
//! [1]
    QFile file("in.txt");
    if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
        return;

    QTextStream in(&file);
    while (!in.atEnd()) {
        QString line = in.readLine();
        process_line(line);
    }
//! [1]
}

static void writeTextStream_snippet()
{
//! [2]
    QFile file("out.txt");
    if (!file.open(QIODevice::WriteOnly | QIODevice::Text))
        return;

    QTextStream out(&file);
    out << "The magic number is: " << 49 << "\n";
//! [2]
}

static void writeDataStream_snippet()
{
    QFile file("out.dat");
    if (!file.open(QIODevice::WriteOnly))
        return;

    QDataStream out(&file);
    out << "The magic number is: " << 49 << "\n";
}

static void readRegularEmptyFile_snippet()
{
//! [3]
    QFile file("/proc/modules");
    if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
        return;

    QTextStream in(&file);
    QString line = in.readLine();
    while (!line.isNull()) {
        process_line(line);
        line = in.readLine();
    }
//! [3]
}

int main()
{
    lineByLine_snippet();
    writeStream_snippet();
}