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/* Utility functions for the PDF loaders.
*/
/*
This file is part of VIPS.
VIPS is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
*/
/*
These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <glib/gi18n-lib.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <vips/vips.h>
#include <vips/buf.h>
#include <vips/internal.h>
#include "pforeign.h"
#if defined(HAVE_POPPLER) || defined (HAVE_PDFIUM)
const char *vips__pdf_suffs[] = {
".pdf",
NULL
};
gboolean
vips__pdf_is_a_buffer(const void *buf, size_t len)
{
const char *str = (const char *) buf;
if (len < 4)
return FALSE;
for (size_t i = 0; i < len - 4; i++)
if (vips_isprefix("%PDF", str + i))
return TRUE;
return FALSE;
}
/* PDF v2 allows for offset headers, ie. there may be any number of
* characters of padding before the "%PDF" file marker. These can be
* arbitrary printer control characters, whitespace, etc.
*
* In practice, the amount of padding is usually small (less than 32
* bytes).
*
* Another strategy is to look for "%EOF" in the final 1k of the file, but of
* course that won't work well for streamed data.
*/
#define MAX_OFFSET (32)
gboolean
vips__pdf_is_a_file(const char *filename)
{
unsigned char buf[MAX_OFFSET];
if (vips__get_bytes(filename, buf, MAX_OFFSET) == MAX_OFFSET &&
vips__pdf_is_a_buffer(buf, MAX_OFFSET))
return TRUE;
return FALSE;
}
gboolean
vips__pdf_is_a_source(VipsSource *source)
{
const unsigned char *p;
return (p = vips_source_sniff(source, MAX_OFFSET)) &&
vips__pdf_is_a_buffer(p, MAX_OFFSET);
}
#endif /*defined(HAVE_POPPLER) || defined (HAVE_PDFIUM)*/
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