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qpdf/examples/pdf-c-objects.c
2023-06-02 16:00:40 +01:00

93 lines
2.4 KiB
C

/* This is an example program to demonstrate use of object handle functions in the C API. */
#include <qpdf/qpdf-c.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
static char const* whoami = 0;
static void
usage()
{
fprintf(stderr, "Usage: %s infile infile-password outfile\n", whoami);
exit(2);
}
QPDF_BOOL
modify_file(qpdf_data qpdf)
{
/* This small example performs the following operation on the document catalog (a.k.a. root):
* - Remove PageLayout
* - Remove OpenAction
* - If there are outlines, set PageMode to UseOutlines; otherwise,
* remove it.
*/
qpdf_oh root = qpdf_get_root(qpdf);
qpdf_oh_remove_key(qpdf, root, "/PageLayout");
qpdf_oh_remove_key(qpdf, root, "/OpenAction");
/* 0 is never a valid qpdf_oh */
qpdf_oh pagemode = 0;
if (qpdf_oh_is_dictionary(qpdf, qpdf_oh_get_key(qpdf, root, "/PageLabels"))) {
pagemode = qpdf_oh_new_name(qpdf, "/UseOutlines");
} else {
pagemode = qpdf_oh_new_null(qpdf);
}
qpdf_oh_replace_or_remove_key(qpdf, root, "/PageMode", pagemode);
return QPDF_TRUE;
}
int
main(int argc, char* argv[])
{
char* infile = NULL;
char* password = NULL;
char* outfile = NULL;
qpdf_data qpdf = qpdf_init();
int warnings = 0;
int errors = 0;
char* p = 0;
if ((p = strrchr(argv[0], '/')) != NULL) {
whoami = p + 1;
} else if ((p = strrchr(argv[0], '\\')) != NULL) {
whoami = p + 1;
} else {
whoami = argv[0];
}
if (argc != 4) {
usage();
}
infile = argv[1];
password = argv[2];
outfile = argv[3];
if (((qpdf_read(qpdf, infile, password) & QPDF_ERRORS) == 0) && modify_file(qpdf) &&
((qpdf_init_write(qpdf, outfile) & QPDF_ERRORS) == 0)) {
/* Use static ID for testing only. For production, a non-static ID is used. See also
* qpdf_set_deterministic_ID. */
qpdf_set_static_ID(qpdf, QPDF_TRUE); /* for testing only */
qpdf_write(qpdf);
}
while (qpdf_more_warnings(qpdf)) {
warnings = 1;
printf("warning: %s\n", qpdf_get_error_full_text(qpdf, qpdf_next_warning(qpdf)));
}
if (qpdf_has_error(qpdf)) {
errors = 1;
printf("error: %s\n", qpdf_get_error_full_text(qpdf, qpdf_get_error(qpdf)));
}
qpdf_cleanup(&qpdf);
if (errors) {
return 2;
} else if (warnings) {
return 3;
}
return 0;
}