python工具-c-struct-decode

示例

# 编译运行C代码
gcc c-struct.c
./a.out
# 生成 1.bin 文件， 内容是一个 demo_head+3*demo_info# 使用 python 解析
python c-struct-decode.py
# 输入结果如下：
1.txt
unpack requires a buffer of 4 bytes
type:1
version:0
path:12
indexs:4===========index: 0==============
timestamp:1886221359
flag:0
desc:===========index: 1==============
timestamp:256
flag:0
desc:hello===========index: 2==============
timestamp:558
flag:0
desc:hello===========index: 3==============
timestamp:814
flag:0
desc:hello

C 代码写入

#include <stdio.h>
#include <stdint.h>#pragma pack(4)  // 4字节对齐
typedef struct _head_ {uint32_t type;uint64_t version;char path[12];
}demo_head;#pragma pack(1)  // 1字节对齐
typedef struct _info_ {uint32_t timestamp;char  flag;char  desc[6];
}demo_info;
#pragma pack()int main(){FILE* f = fopen("1.bin", "wb");if (f == NULL) {printf("fopen file fail.\n");return -1;}demo_head h = {1,0,"/tmp"};fwrite(&h, sizeof(demo_head), 1, f);for (size_t i = 0; i < 3; i++) {demo_info info = {i+1, 1, "hello."};fwrite(&info, sizeof(demo_info), 1, f);}fclose(f);return 0;
}

python 代码读取

import argparse
import struct
import osdef get_unpack_info(f, size):if size == 4:return struct.unpack("I", f.read(size))[0]elif size == 1:return struct.unpack("B", f.read(size))[0]elif size == 8:return struct.unpack("Q", f.read(size))[0]class demo_info:sizes = [4,1,6]def __init__(self) -> None:self.timestamp = 0      # 4    self.flag = 0           # 1self.desc = 0           # 6    def __str__(self) -> str:ret =  "timestamp:" + str(self.timestamp) + "\n"ret +=  "flag:" + str(self.flag) + "\n"ret += "desc:" + str(self.desc) + "\n"return retclass demo_head:sizes = [4,8,12]def __init__(self) -> None:self.type = 0         # 4   self.version = 0      # 8   self.path = ""        # 12self.indexs = []def __str__(self) -> str:ret = "type:" + str(self.type) + "\n"ret += "version:" + str(self.version) + "\n"ret += "path:" + str(self.path) + "\n"ret += "indexs:" + str(len(self.indexs)) + "\n"return retdef read_demo_data(file_name):head = demo_head()with open(file_name, "rb") as f:head.type = get_unpack_info(f, demo_head.sizes[0])head.version = get_unpack_info(f, demo_head.sizes[1])head.path = demo_head.sizes[2]while(True):index = demo_info()try:index.timestamp = get_unpack_info(f, demo_info.sizes[0])index.flag = get_unpack_info(f, demo_info.sizes[1])index.desc = str(f.read(demo_info.sizes[2]).decode("utf-8"))head.indexs.append(index)except Exception as e:print(e)breakreturn headif __name__ == "__main__":parser = argparse.ArgumentParser()parser.add_argument('--path', type=str, default = "1.bin")args = parser.parse_args()print(args.path)head = read_demo_data(args.path)    if head:print(head)for i, index in enumerate(head.indexs):print(f"===========index: {i}==============")print(index)