+namespace {
+
+/** Guess the file format name (as in Format::name()) from contents.
+ * Normally you don't want to use this directly, but rather
+ * Formats::getFormatFromFile().
+ */
+string guessFormatFromContents(FileName const & fn)
+{
+ // the different filetypes and what they contain in one of the first lines
+ // (dots are any characters). (Herbert 20020131)
+ // AGR Grace...
+ // BMP BM...
+ // EPS %!PS-Adobe-3.0 EPSF...
+ // FIG #FIG...
+ // FITS ...BITPIX...
+ // GIF GIF...
+ // JPG JFIF
+ // PDF %PDF-...
+ // PNG .PNG...
+ // PBM P1... or P4 (B/W)
+ // PGM P2... or P5 (Grayscale)
+ // PPM P3... or P6 (color)
+ // PS %!PS-Adobe-2.0 or 1.0, no "EPSF"!
+ // SGI \001\332... (decimal 474)
+ // TGIF %TGIF...
+ // TIFF II... or MM...
+ // XBM ..._bits[]...
+ // XPM /* XPM */ sometimes missing (f.ex. tgif-export)
+ // ...static char *...
+ // XWD \000\000\000\151 (0x00006900) decimal 105
+ //
+ // GZIP \037\213 http://www.ietf.org/rfc/rfc1952.txt
+ // ZIP PK... http://www.halyava.ru/document/ind_arch.htm
+ // Z \037\235 UNIX compress
+
+ // paranoia check
+ if (fn.empty() || !fn.isReadableFile())
+ return string();
+
+ ifstream ifs(fn.toFilesystemEncoding().c_str());
+ if (!ifs)
+ // Couldn't open file...
+ return string();
+
+ // gnuzip
+ static string const gzipStamp = "\037\213";
+
+ // PKZIP
+ static string const zipStamp = "PK";
+
+ // ZIP containers (koffice, openoffice.org etc).
+ static string const nonzipStamp = "\008\0\0\0mimetypeapplication/";
+
+ // compress
+ static string const compressStamp = "\037\235";
+
+ // Maximum strings to read
+ int const max_count = 50;
+ int count = 0;
+
+ string str;
+ string format;
+ bool firstLine = true;
+ while ((count++ < max_count) && format.empty()) {
+ if (ifs.eof()) {
+ LYXERR(Debug::GRAPHICS, "filetools(getFormatFromContents)\n"
+ << "\tFile type not recognised before EOF!");
+ break;
+ }
+
+ getline(ifs, str);
+ string const stamp = str.substr(0, 2);
+ if (firstLine && str.size() >= 2) {
+ // at first we check for a zipped file, because this
+ // information is saved in the first bytes of the file!
+ // also some graphic formats which save the information
+ // in the first line, too.
+ if (prefixIs(str, gzipStamp)) {
+ format = "gzip";
+
+ } else if (stamp == zipStamp &&
+ !contains(str, nonzipStamp)) {
+ format = "zip";
+
+ } else if (stamp == compressStamp) {
+ format = "compress";
+
+ // the graphics part
+ } else if (stamp == "BM") {
+ format = "bmp";
+
+ } else if (stamp == "\001\332") {
+ format = "sgi";
+
+ // PBM family
+ // Don't need to use str.at(0), str.at(1) because
+ // we already know that str.size() >= 2
+ } else if (str[0] == 'P') {
+ switch (str[1]) {
+ case '1':
+ case '4':
+ format = "pbm";
+ break;
+ case '2':
+ case '5':
+ format = "pgm";
+ break;
+ case '3':
+ case '6':
+ format = "ppm";
+ }
+ break;
+
+ } else if ((stamp == "II") || (stamp == "MM")) {
+ format = "tiff";
+
+ } else if (prefixIs(str,"%TGIF")) {
+ format = "tgif";
+
+ } else if (prefixIs(str,"#FIG")) {
+ format = "fig";
+
+ } else if (prefixIs(str,"GIF")) {
+ format = "gif";
+
+ } else if (str.size() > 3) {
+ int const c = ((str[0] << 24) & (str[1] << 16) &
+ (str[2] << 8) & str[3]);
+ if (c == 105) {
+ format = "xwd";
+ }
+ }
+
+ firstLine = false;
+ }
+
+ if (!format.empty())
+ break;
+ else if (contains(str,"EPSF"))
+ // dummy, if we have wrong file description like
+ // %!PS-Adobe-2.0EPSF"
+ format = "eps";
+
+ else if (contains(str, "Grace"))
+ format = "agr";
+
+ else if (contains(str, "JFIF"))
+ format = "jpg";
+
+ else if (contains(str, "%PDF"))
+ format = "pdf";
+
+ else if (contains(str, "PNG"))
+ format = "png";
+
+ else if (contains(str, "%!PS-Adobe")) {
+ // eps or ps
+ ifs >> str;
+ if (contains(str,"EPSF"))
+ format = "eps";
+ else
+ format = "ps";
+ }
+
+ else if (contains(str, "_bits[]"))
+ format = "xbm";
+
+ else if (contains(str, "XPM") || contains(str, "static char *"))
+ format = "xpm";
+
+ else if (contains(str, "BITPIX"))
+ format = "fits";
+ }
+
+ if (!format.empty()) {
+ LYXERR(Debug::GRAPHICS, "Recognised Fileformat: " << format);
+ return format;
+ }
+
+ LYXERR(Debug::GRAPHICS, "filetools(getFormatFromContents)\n"
+ << "\tCouldn't find a known format!");
+ return string();
+}
+
+}
+
+
projects / features.git / commitdiff