/*
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% %
% %
% %
+ G e t M a g i c I n f o %
% %
% %
% %
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%
% GetMagicInfo() searches the magic list for the specified name and if found
% returns attributes for that magic.
%
% The format of the GetMagicInfo method is:
%
% const MagicInfo *GetMagicInfo(const unsigned char *magic,
% const size_t length,ExceptionInfo *exception)
%
% A description of each parameter follows:
%
% o magic: A binary string generally representing the first few characters
% of the image file or blob.
%
% o length: The length of the binary signature.
%
% o exception: Return any errors or warnings in this structure.
%
*/
MagickExport const MagicInfo *GetMagicInfo(const unsigned char *magic,
const size_t length,ExceptionInfo *exception)
{
register const MagicInfo
*p;
assert(exception != (ExceptionInfo *) NULL);
if ((magic_list == (LinkedListInfo *) NULL) ||
(instantiate_magic == MagickFalse))
if (InitializeMagicList(exception) == MagickFalse)
return((const MagicInfo *) NULL);
if ((magic_list == (LinkedListInfo *) NULL) ||
(IsLinkedListEmpty(magic_list) != MagickFalse))
return((const MagicInfo *) NULL);
if ((magic == (const unsigned char *) NULL) || (length == 0))
return((const MagicInfo *) GetValueFromLinkedList(magic_list,0));
if (length == 0)
return((const MagicInfo *) NULL);
/*
Search for requested magic.
*/
AcquireSemaphoreInfo(&magic_semaphore);
ResetLinkedListIterator(magic_list);
p=(const MagicInfo *) GetNextValueInLinkedList(magic_list);
while (p != (const MagicInfo *) NULL)
{
assert(p->offset >= 0);
if (((size_t) (p->offset+p->length) <= length) &&
(memcmp(magic+p->offset,p->magic,p->length) == 0))
break;
p=(const MagicInfo *) GetNextValueInLinkedList(magic_list);
}
RelinquishSemaphoreInfo(magic_semaphore);
return((const MagicInfo *) p);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
+ G e t M a g i c I n f o %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% GetMagicInfo() searches the magic list for the specified name and if found
% returns attributes for that magic.
%
% The format of the GetMagicInfo method is:
%
% const MagicInfo *GetMagicInfo(const unsigned char *magic,
% const size_t length,ExceptionInfo *exception)
%
% A description of each parameter follows:
%
% o magic: A binary string generally representing the first few characters
% of the image file or blob.
%
% o length: the length of the binary signature.
%
% o exception: return any errors or warnings in this structure.
%
*/
MagickExport const MagicInfo *GetMagicInfo(const unsigned char *magic,
const size_t length,ExceptionInfo *exception)
{
register const MagicInfo
*p;
assert(exception != (ExceptionInfo *) NULL);
if ((magic_list == (LinkedListInfo *) NULL) ||
(instantiate_magic == MagickFalse))
if (InitializeMagicList(exception) == MagickFalse)
return((const MagicInfo *) NULL);
if ((magic_list == (LinkedListInfo *) NULL) ||
(IsLinkedListEmpty(magic_list) != MagickFalse))
return((const MagicInfo *) NULL);
if (magic == (const unsigned char *) NULL)
return((const MagicInfo *) GetValueFromLinkedList(magic_list,0));
if (length == 0)
return((const MagicInfo *) NULL);
/*
Search for magic tag.
*/
LockSemaphoreInfo(magic_semaphore);
ResetLinkedListIterator(magic_list);
p=(const MagicInfo *) GetNextValueInLinkedList(magic_list);
while (p != (const MagicInfo *) NULL)
{
assert(p->offset >= 0);
if (((size_t) (p->offset+p->length) <= length) &&
(memcmp(magic+p->offset,p->magic,p->length) == 0))
break;
p=(const MagicInfo *) GetNextValueInLinkedList(magic_list);
}
if (p != (const MagicInfo *) NULL)
(void) InsertValueInLinkedList(magic_list,0,
RemoveElementByValueFromLinkedList(magic_list,p));
UnlockSemaphoreInfo(magic_semaphore);
return(p);
}
