![](/img/trans.png)
[英]how to append unsigned short after char buffer array containing hex byte
[英]How to write a unsigned char* array containing hex values to file in python
我有一个C dll,它以不带符号的char *形式返回PDF文件,其中包含十六进制值。 如何使用ctypes检索此数组并将其保存到“挖掘” PDF文件中?
例如,在CI中执行以下操作:
unsigned char* manual = getPluginManualAsPDF(mPlugin);
long nrOfBytes = getPluginManualNrOfBytes(mPlugin);
string tempFile(mtk::JoinPath(getTempFolder(getRRHandleFromPlugin(mPlugin)), "AddNoisePluginDoc.pdf"));
ofstream temp(tempFile.c_str(), std::ios::binary);
long byteNr = 0;
while (byteNr < nrOfBytes)
{
temp<< manual[byteNr];
byteNr++;
}
temp.close();
//Spanw an external pdf reader
ShellExecute(Handle, "open", tempFile.c_str(), NULL, NULL,SW_SHOWNORMAL) ;
}
我正在尝试通过CTypes访问相同的函数(getPluginManualAsPDF和getPluginManualNrOfBytes),即
rrpLib.getPluginManualAsPDF.restype = c_buffer
def getPluginManualAsPDF(pluginHandle):
return rrpLib.getPluginManualAsPDF(pluginHandle)
def getPluginManualNrOfBytes(pluginHandle):
return rrpLib.getPluginManualNrOfBytes(pluginHandle)
但是有返回getPluginManualAsPDF()函数的问题。任何帮助表示赞赏。
假设您的getPluginManualAsPDF
和getPluginManualNrOfBytes
具有以下原型:
/* FIXME: the type of `mPlugin` isn't clear, is it void * ? */
unsigned char * getPluginManualAsPDF(void *mPlugin) {
static unsigned char manual[] = {1, 2, 3};
return manual;
}
long getPluginManualNrOfBytes(void *mPlugin) {
return 12345;
}
您可以使用以下命令调用这两个函数:
from ctypes import *
rrpLib = cdll.rrpLib # or windll if it use STDCALL
getPluginManualAsPDF = rrpLib.getPluginManualAsPDF
getPluginManualAsPDF.restype = POINTER(c_ubyte)
getPluginManualAsPDF.argtypes = [c_void_p]
getPluginManualNrOfBytes = rrpLib.getPluginManualNrOfBytes
getPluginManualNrOfBytes.restype = c_long
getPluginManualNrOfBytes.argtypes = [c_void_p]
例如:
# gcc -Wall rrpLib.c -shared -o rrpLib.dll
# python
>>> from ctypes import *
>>>
>>> rrpLib = cdll.rrpLib # or windll if it uses STDCALL
>>>
>>> getPluginManualAsPDF = rrpLib.getPluginManualAsPDF
>>> getPluginManualAsPDF.restype = POINTER(c_ubyte)
>>> getPluginManualAsPDF.argtypes = [c_void_p]
>>>
>>> getPluginManualNrOfBytes = rrpLib.getPluginManualNrOfBytes
>>> getPluginManualNrOfBytes.restype = c_long
>>> getPluginManualNrOfBytes.argtypes = [c_void_p]
>>>
>>> getPluginManualAsPDF(None)[0]
1
>>> getPluginManualAsPDF(None)[1]
2
>>> getPluginManualAsPDF(None)[2]
3
>>>
>>>
>>> ptr = getPluginManualAsPDF(None)
>>> manual = cast(ptr, POINTER(c_ubyte * 3))[0]
>>> manual
<__main__.c_ubyte_Array_3 object at 0x017801C0>
>>> open('out.txt', 'wb').write(bytearray(manual))
>>> open('out.txt').read()
'\x01\x02\x03'
>>>
>>>
>>> getPluginManualNrOfBytes(None)
12345
>>>
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.