blob: 529f6bdc19aaf5272cc0935f5f0543754ef2d5e6 (
plain) (
blame)
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
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
|
//
// This example illustrates the use of QPDFObjectHandle::TokenFilter
// with filterContents. See also pdf-filter-tokens.cc for an example
// that uses QPDFObjectHandle::TokenFilter with addContentTokenFilter.
//
#include <iostream>
#include <stdlib.h>
#include <string.h>
#include <qpdf/Pl_StdioFile.hh>
#include <qpdf/QPDF.hh>
#include <qpdf/QPDFObjectHandle.hh>
#include <qpdf/QPDFPageDocumentHelper.hh>
#include <qpdf/QPDFPageObjectHelper.hh>
#include <qpdf/QUtil.hh>
static char const* whoami = nullptr;
void
usage()
{
std::cerr << "Usage: " << whoami << " infile" << std::endl
<< "Applies token filters to infile" << std::endl;
exit(2);
}
class StringCounter: public QPDFObjectHandle::TokenFilter
{
public:
StringCounter() :
count(0)
{
}
virtual ~StringCounter() = default;
virtual void handleToken(QPDFTokenizer::Token const&);
virtual void handleEOF();
int getCount() const;
private:
int count;
};
void
StringCounter::handleToken(QPDFTokenizer::Token const& token)
{
// Count string tokens
if (token.getType() == QPDFTokenizer::tt_string) {
++this->count;
}
// Preserve input verbatim by passing each token to any specified
// downstream filter.
writeToken(token);
}
void
StringCounter::handleEOF()
{
// Write a comment at the end of the stream just to show how we
// can enhance the output if we want.
write("\n% strings found: ");
write(std::to_string(this->count));
}
int
StringCounter::getCount() const
{
return this->count;
}
int
main(int argc, char* argv[])
{
whoami = QUtil::getWhoami(argv[0]);
if (argc != 2) {
usage();
}
char const* infilename = argv[1];
try {
QPDF pdf;
pdf.processFile(infilename);
int pageno = 0;
for (auto& page: QPDFPageDocumentHelper(pdf).getAllPages()) {
++pageno;
// Pass the contents of a page through our string counter.
// If it's an even page, capture the output. This
// illustrates that you may capture any output generated
// by the filter, or you may ignore it.
StringCounter counter;
if (pageno % 2) {
// Ignore output for odd pages.
page.filterContents(&counter);
} else {
// Write output to stdout for even pages.
Pl_StdioFile out("stdout", stdout);
std::cout << "% Contents of page " << pageno << std::endl;
page.filterContents(&counter, &out);
std::cout << "\n% end " << pageno << std::endl;
}
std::cout << "Page " << pageno
<< ": strings = " << counter.getCount() << std::endl;
}
} catch (std::exception& e) {
std::cerr << whoami << ": " << e.what() << std::endl;
exit(2);
}
return 0;
}
|
