1 files changed, 213 insertions, 0 deletions

diff --git a/src/plugins/ps_extractor.c b/src/plugins/ps_extractor.c
new file mode 100644
index 0000000..bd99c94
--- /dev/null
+++ b/src/plugins/ps_extractor.c
@@ -0,0 +1,213 @@
+/*
+     This file is part of libextractor.
+     (C) 2002, 2003, 2009, 2012 Vidyut Samanta and Christian Grothoff
+
+     libextractor is free software; you can redistribute it and/or modify
+     it under the terms of the GNU General Public License as published
+     by the Free Software Foundation; either version 3, or (at your
+     option) any later version.
+
+     libextractor 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
+     General Public License for more details.
+
+     You should have received a copy of the GNU General Public License
+     along with libextractor; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+ */
+/**
+ * @file plugins/ps_extractor.c
+ * @brief plugin to support PostScript files
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "extractor.h"
+
+
+/**
+ * Maximum length of a single line in the PostScript file we're
+ * willing to look at.  While the body of the file can have longer
+ * lines, this should be a sane limit for the lines in the header with
+ * the meta data.
+ */
+#define MAX_LINE (1024)
+
+/**
+ * Header of a PostScript file.
+ */
+#define PS_HEADER "%!PS-Adobe"
+
+
+/**
+ * Pair with prefix in the PS header and corresponding LE type.
+ */
+struct Matches
+{
+  /**
+   * PS header prefix.
+   */
+  const char *prefix;
+  
+  /**
+   * Corresponding LE type.
+   */
+  enum EXTRACTOR_MetaType type;
+};
+
+
+/**
+ * Map of PS prefixes to LE types.
+ */
+static struct Matches tests[] = {
+  { "%%Title: ", EXTRACTOR_METATYPE_TITLE },
+  { "% Subject: ", EXTRACTOR_METATYPE_SUBJECT },
+  { "%%Author: ", EXTRACTOR_METATYPE_AUTHOR_NAME },
+  { "% From: ", EXTRACTOR_METATYPE_AUTHOR_NAME },
+  { "%%Version: ", EXTRACTOR_METATYPE_REVISION_NUMBER },
+  { "%%Creator: ", EXTRACTOR_METATYPE_CREATED_BY_SOFTWARE },
+  { "%%CreationDate: ", EXTRACTOR_METATYPE_CREATION_DATE },
+  { "% Date: ", EXTRACTOR_METATYPE_UNKNOWN_DATE },
+  { "%%Pages: ", EXTRACTOR_METATYPE_PAGE_COUNT },
+  { "%%Orientation: ", EXTRACTOR_METATYPE_PAGE_ORIENTATION },
+  { "%%DocumentPaperSizes: ", EXTRACTOR_METATYPE_PAPER_SIZE },
+  { "%%PageOrder: ", EXTRACTOR_METATYPE_PAGE_ORDER },
+  { "%%LanguageLevel: ", EXTRACTOR_METATYPE_FORMAT_VERSION },
+  { "%%Magnification: ", EXTRACTOR_METATYPE_MAGNIFICATION },
+
+  /* Also widely used but not supported since they
+     probably make no sense:
+     "%%BoundingBox: ",
+     "%%DocumentNeededResources: ",
+     "%%DocumentSuppliedResources: ",
+     "%%DocumentProcSets: ",
+     "%%DocumentData: ", */
+
+  { NULL, 0 }
+};
+
+
+/**
+ * Read a single ('\n'-terminated) line of input.
+ *
+ * @param ec context for IO
+ * @return NULL on end-of-file (or if next line exceeds limit)
+ */
+static char *
+readline (struct EXTRACTOR_ExtractContext *ec)
+{
+  int64_t pos;
+  ssize_t ret;
+  char *res;
+  void *data;
+  const char *cdata;
+  const char *eol;
+
+  pos = ec->seek (ec->cls, 0, SEEK_CUR);
+  if (0 >= (ret = ec->read (ec->cls, &data, MAX_LINE)))
+    return NULL; 
+  cdata = data;
+  if (NULL == (eol = memchr (cdata, '\n', ret)))
+    return NULL; /* no end-of-line found */
+  if (NULL == (res = malloc (eol - cdata + 1)))
+    return NULL;
+  memcpy (res, cdata, eol - cdata);
+  res[eol - cdata] = '\0';
+  ec->seek (ec->cls, pos + eol - cdata + 1, SEEK_SET);
+  return res;
+}
+
+
+/**
+ * Main entry method for the 'application/postscript' extraction plugin.  
+ *
+ * @param ec extraction context provided to the plugin
+ */
+void
+EXTRACTOR_ps_extract_method (struct EXTRACTOR_ExtractContext *ec)
+{
+  unsigned int i;
+  char *line;
+  char *next;
+  char *acc;
+  const char *match;
+
+  if (NULL == (line = readline (ec)))
+    return;
+  if ( (strlen (line) < strlen (PS_HEADER)) ||
+       (0 != memcmp (PS_HEADER,
+                     line,
+                     strlen (PS_HEADER))) )
+    {
+      free (line);
+      return;
+    }
+  free (line);
+  if (0 != ec->proc (ec->cls,
+                     "ps",
+                     EXTRACTOR_METATYPE_MIMETYPE,
+                     EXTRACTOR_METAFORMAT_UTF8,
+                     "text/plain",
+                     "application/postscript",
+                     strlen ("application/postscript") + 1))
+    return;
+  
+  line = NULL;
+  next = readline (ec);
+  while ( (NULL != next) &&
+          ('%' == next[0]) )
+    {
+      line = next;
+      next = readline (ec);
+      for (i = 0; NULL != tests[i].prefix; i++)
+        {
+          match = tests[i].prefix;
+          if ( (strlen (line) < strlen (match)) ||
+               (0 != strncmp (line, match, strlen (match))) )
+            continue;
+          /* %%+ continues previous meta-data type... */
+          while ( (NULL != next) &&
+                  (0 == strncmp (next, "%%+", strlen ("%%+"))) )
+            {
+              acc = malloc (strlen (line) + strlen (next) - 1);
+              strcpy (acc, line);
+              strcat (acc, " ");
+              strcat (acc, next + 3);
+              free (line);
+              line = acc;
+              next = readline (ec);
+            }
+          if ( (line[strlen (line) - 1] == ')') && 
+               (line[strlen (match)] == '(') )
+            {
+              acc = &line[strlen (match) + 1];
+              acc[strlen (acc) - 1] = '\0'; /* remove ")" */
+            }
+          else
+            {
+              acc = &line[strlen (match)];
+            }
+          while (isspace ((unsigned int) acc[0]))
+            acc++;
+          if ( (strlen (acc) > 0) &&
+               (0 != ec->proc (ec->cls,
+                               "ps",
+                               tests[i].type,
+                               EXTRACTOR_METAFORMAT_UTF8,
+                               "text/plain",
+                               acc,
+                               strlen (acc) + 1)) )
+            {
+              free (line);
+              if (NULL != next)
+                free (next);
+              return;
+            }
+          break;
+        }
+      free (line);
+    }
+}
+
+/* end of ps_extractor.c */