python中buf函数 python buf

如何用python解析获取C源文件的函数名

class stdata(Structure):

_fields_ = [('pBuf', c_char_p), ('buflen', c_int)]

N=100

buf = create_string_buffer(N)

d = stdata()

d.buflen = N

d.pBuf = cast(buf, c_char_p)

n = CallMyCFunc_GetData(byref(d))

关键在于create_string_buffer创建可写buffer；cast转换为char*类型。

相关问答

Q1: 如何使用Python中的buffer

1.需要安装Protocol Buffer

直接：apt-get install protobuf-compiler

安装完毕后，进入解压目录的Python目录，执行python setup.py install；安装python的protobuf库即可。

2.可以查询到它的大致用法

pijing@ubuntu:~/protobuffer$ protoc -h

Usage: protoc [OPTION] PROTO_FILES

Parse PROTO_FILES and generate output based on the options given:

-IPATH, --proto_path=PATH Specify the directory in which to search for

imports. May be specified multiple times;

directories will be searched in order. If not

given, the current working directory is used.

--version Show version info and exit.

-h, --help Show this text and exit.

--encode=MESSAGE_TYPE Read a text-format message of the given type

from standard input and write it in binary

to standard output. The message type must

be defined in PROTO_FILES or their imports.

--decode=MESSAGE_TYPE Read a binary message of the given type from

standard input and write it in text format

to standard output. The message type must

be defined in PROTO_FILES or their imports.

--decode_raw Read an arbitrary protocol message from

standard input and write the raw tag/value

pairs in text format to standard output. No

PROTO_FILES should be given when using this

flag.

-oFILE, Writes a FileDescriptorSet (a protocol buffer,

--descriptor_set_out=FILE defined in descriptor.proto) containing all of

the input files to FILE.

--include_imports When using --descriptor_set_out, also include

all dependencies of the input files in the

set, so that the set is self-contained.

--include_source_info When using --descriptor_set_out, do not strip

SourceCodeInfo from the FileDescriptorProto.

This results in vastly larger descriptors that

include information about the original

location of each decl in the source file as

well as surrounding comments.

--error_format=FORMAT Set the format in which to print errors.

FORMAT may be 'gcc' (the default) or 'msvs'

(Microsoft Visual Studio format).

--plugin=EXECUTABLE Specifies a plugin executable to use.

Normally, protoc searches the PATH for

plugins, but you may specify additional

executables not in the path using this flag.

Additionally, EXECUTABLE may be of the form

NAME=PATH, in which case the given plugin name

is mapped to the given executable even if

the executable's own name differs.

--cpp_out=OUT_DIR Generate C++ header and source.

--java_out=OUT_DIR Generate Java source file.

--python_out=OUT_DIR Generate Python source file.

3.简单使用一下

首先定义proto文件，my.proto

{

optional int32 id=1;

optional string testname=2;

}

然后，执行命令：

protoc --python_out=./ ./my.proto

得到my_pb2.py文件

最后，在当前目录下新建一个test.py文件夹，写入测试的脚本，包括序列化和反序列化代码：

Q2: python里使用socket编程时的buf一般怎么实现的

用缓冲区我觉得可以这样。

import array

import struct

buf=array.array('c',struct.pack('1024s',1024*''))

buf[0]='s'