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iflDatabase(3)    Image Format Library C++ Reference Manual     iflDatabase(3)



NAME
     iflDatabase - access to image file format database

INHERITS FROM
     This is a base class with no inheritance.


HEADER FILE
     #include <il/iflDatabase.h>


CLASS DESCRIPTION
     iflDatabase is a lightweight version of the iflFormat class, with
     abbreviated functionality.  Basically, the information here is what can
     be obtained from variables in the file format database without opening
     the specific DSO.  Looking up an object of this class will never cause a
     DSO to be opened.  The intended use is by apps who know they only need
     the restricted methods provided here.

     Refer to the iflFormat(3) man page for more detail on iflFormat
     functionality.

CLASS MEMBER FUNCTION SUMMARY
   Format lookup
          static iflDatabase* findNext(int& index)
          static iflDatabase* findByMagic(int fd)
          static iflDatabase* findByFormatName(const char* formatName)
          static iflDatabase* findByFileName(const char* fileName,
                                             int noMatchRule=TRUE)


   Attribute queries
          const char* getName()
          const char* getDefaultSuffix()
          const char* getDescription()
          int accessModeIsSupported(int mode)
          const char* getDSOName()
          const char* getInstSubSystem()


   Conversion to iflFormat
          iflFormat* getFormat(int openDSOifNecessary = TRUE)



FUNCTION DESCRIPTIONS
     accessModeIsSupported()

          int accessModeIsSupported(int mode)






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iflDatabase(3)    Image Format Library C++ Reference Manual     iflDatabase(3)



          This member function tells whether the given access mode (which must
          be one of O_RDONLY, O_WRONLY, or O_RDWR) is supported by the
          subclass.

     findByFileName()

          static iflDatabase* findByFileName(const char* fileName,
                                             int noMatchRule=TRUE)


          This static class member function is used to look up an image file
          format by file name, where the file name is given by the fileName
          argument.  This is accomplished by matching the tail end of fileName
          against each value of the suffixes variable given for each image
          file format in the FTR database.  The noMatchRule argument can be
          used to limit searching to those formats that have no match rule.

     findByFormatName()

          static iflDatabase* findByFormatName(const char* formatName)


          This static class member function is used to look up an image file
          format by name, where the name is given by the formatName argument.

     findByMagic()

          static iflDatabase* findByMagic(int fd)


          This static class member function is used to look up an image file
          format by magic number of a given file that is open for reading with
          the file descriptor, fd.

     findNext()

          static iflDatabase* findNext(int& index)


          This static class member function is used to step through the
          (static, lazily created) list of supported file formats.

     To start searching initialize the index paramter to zero.  It will be
     automatically updated by each call so that successive calls will iterate
     through all available formats.  If there are no more formats, the
     function returns NULL.

          The following example prints the names of all supported formats:

              iflDatabase *db;
              int index = 0;
              while ((db = iflDatabase::findNext(index)) != NULL)



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iflDatabase(3)    Image Format Library C++ Reference Manual     iflDatabase(3)



                  printf("%s0, db->getName());


     getDSOName()

          const char* getDSOName()


          This member function returns the 'soname' for the DSO that
          implements this format (used internally to pass to dlopen()).

     getDefaultSuffix()

          const char* getDefaultSuffix()


          This member function returns the default filename suffix (the first
          suffix listed in the "suffixes" declaration for a format in the IFL
          format database). The returned value is a pointer to a static string
          that is valid forever. Note that the returned value may be NULL.

     getDescription()

          const char* getDescription()


          This member function returns the format description, or NULL if
          there is none.

     getFormat()

          iflFormat* getFormat(int openDSOifNecessary = TRUE)


          This method returns the full iflFormat correspnding to this
          iflDatabase object.  This may involve some overhead the first time a
          particular format is accessed (opening the DSO and such).

     getInstSubSystem()

          const char* getInstSubSystem()


          This member function returns the inst sub-system that must be
          installed to use this format.  This is used internally to format
          error messages.

     getName()

          const char* getName()





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iflDatabase(3)    Image Format Library C++ Reference Manual     iflDatabase(3)



          This member function returns the format name, which is a pointer to
          a static string that is valid forever.

SEE ALSO
     iflFormat


















































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