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qpdf/examples/pdf-double-page-size.cc
Jay Berkenbilt d71f05ca07 Fix sign and conversion warnings (major)
This makes all integer type conversions that have potential data loss
explicit with calls that do range checks and raise an exception. After
this commit, qpdf builds with no warnings when -Wsign-conversion
-Wconversion is used with gcc or clang or when -W3 -Wd4800 is used
with MSVC. This significantly reduces the likelihood of potential
crashes from bogus integer values.

There are some parts of the code that take int when they should take
size_t or an offset. Such places would make qpdf not support files
with more than 2^31 of something that usually wouldn't be so large. In
the event that such a file shows up and is valid, at least qpdf would
raise an error in the right spot so the issue could be legitimately
addressed rather than failing in some weird way because of a silent
overflow condition.
2019-06-21 13:17:21 -04:00

125 lines
3.1 KiB
C++

#include <iostream>
#include <string.h>
#include <stdlib.h>
#include <qpdf/QPDF.hh>
#include <qpdf/QPDFPageDocumentHelper.hh>
#include <qpdf/QPDFPageObjectHelper.hh>
#include <qpdf/QUtil.hh>
#include <qpdf/Buffer.hh>
#include <qpdf/QPDFWriter.hh>
static char const* whoami = 0;
void usage()
{
std::cerr << "Usage: " << whoami << " infile.pdf outfile.pdf [in-password]"
<< std::endl
<< "Double size of all pages in infile.pdf;"
<< " write output to outfile.pdf" << std::endl;
exit(2);
}
static void doubleBoxSize(QPDFObjectHandle& page, char const* box_name)
{
// If there is a box of this name, replace it with a new box whose
// elements are double the values of the original box.
QPDFObjectHandle box = page.getKey(box_name);
if (box.isNull())
{
return;
}
if (! (box.isArray() && (box.getArrayNItems() == 4)))
{
throw std::runtime_error(std::string("box ") + box_name +
" is not an array of four elements");
}
std::vector<QPDFObjectHandle> doubled;
for (int i = 0; i < 4; ++i)
{
doubled.push_back(
QPDFObjectHandle::newReal(
box.getArrayItem(i).getNumericValue() * 2.0, 2));
}
page.replaceKey(box_name, QPDFObjectHandle::newArray(doubled));
}
int main(int argc, char* argv[])
{
whoami = QUtil::getWhoami(argv[0]);
// For libtool's sake....
if (strncmp(whoami, "lt-", 3) == 0)
{
whoami += 3;
}
// For test suite
bool static_id = false;
if ((argc > 1) && (strcmp(argv[1], " --static-id") == 0))
{
static_id = true;
--argc;
++argv;
}
if (! ((argc == 3) || (argc == 4)))
{
usage();
}
char const* infilename = argv[1];
char const* outfilename = argv[2];
char const* password = (argc == 4) ? argv[3] : "";
// Text to prepend to each page's contents
std::string content = "2 0 0 2 0 0 cm\n";
try
{
QPDF qpdf;
qpdf.processFile(infilename, password);
std::vector<QPDFPageObjectHelper> pages =
QPDFPageDocumentHelper(qpdf).getAllPages();
for (std::vector<QPDFPageObjectHelper>::iterator iter =
pages.begin();
iter != pages.end(); ++iter)
{
QPDFPageObjectHelper& ph(*iter);
QPDFObjectHandle page = ph.getObjectHandle();
// Prepend the buffer to the page's contents
ph.addPageContents(
QPDFObjectHandle::newStream(&qpdf, content), true);
// Double the size of each of the content boxes
doubleBoxSize(page, "/MediaBox");
doubleBoxSize(page, "/CropBox");
doubleBoxSize(page, "/BleedBox");
doubleBoxSize(page, "/TrimBox");
doubleBoxSize(page, "/ArtBox");
}
// Write out a new file
QPDFWriter w(qpdf, outfilename);
if (static_id)
{
// For the test suite, uncompress streams and use static
// IDs.
w.setStaticID(true); // for testing only
w.setStreamDataMode(qpdf_s_uncompress);
}
w.write();
std::cout << whoami << ": new file written to " << outfilename
<< std::endl;
}
catch (std::exception &e)
{
std::cerr << whoami << " processing file " << infilename << ": "
<< e.what() << std::endl;
exit(2);
}
return 0;
}