frida native层操作读写文件

function main(){
    write_file1()
    write_File2()
}
function write_file1(){
    //使用firda的自带api
    var file = new File("/data/local/tmp/mytest.dat")
    file.write("1234");
    file.flush();
    file.close();
}

function removeFile(filePath) {
    var addr_remove = Module.findExportByName("libc.so", "remove");
    var remove = new NativeFunction(addr_remove, "int", ["pointer"]);

    var filename = Memory.allocUtf8String(filePath);
    var result = remove(filename);

    if (result === 0) {
        console.log("文件已删除");
    } else {
        console.log("无法删除文件");
    }
}

// 示例使用

function checkFileExist(filePath) {
    var addr_access = Module.findExportByName("libc.so", "access");
    var access = new NativeFunction(addr_access, "int", ["pointer", "int"]);

    var filename = Memory.allocUtf8String(filePath);
    var result = access(filename, 0); // 使用0作为第二个参数，表示仅检查文件是否存在

    if (result === 0) {
        console.log(`文件:${filePath}存在,准备删除`);
        removeFile(filePath);
    } else {
        console.log("文件不存在");
    }
}
function write_File2(){
    var addr_fopen = Module.findExportByName("libc.so","fopen")
    var addr_fputs = Module.findExportByName("libc.so","fputs")
    var addr_fclose= Module.findExportByName("libc.so","fclose")
    //NativeFunction 将地址创建为可调用的函数,第一个参数是函数地址，第二个参数是返回值类型，所有指针类型，包括string(char*),都是pointer
    //第三个参数就是原函数的参数列表

    var fopen = new NativeFunction(addr_fopen,"pointer",["pointer","pointer"])
    var fputs = new NativeFunction(addr_fputs,"int",["pointer","pointer"]);
    var fclose = new NativeFunction(addr_fclose,"int",["pointer"]);

    var filename = Memory.allocUtf8String("/data/local/tmp/mytest.dat"); //native层需要这样创建字符串，在java层就可以直接写字符串
    var open_mode = Memory.allocUtf8String("w+");
    var file = fopen(filename,open_mode);

    var buffer_str = Memory.allocUtf8String("1234")
    var ret = fputs(buffer_str,file);
    console.log("fputs ret:",ret);
    fclose(file);
}
setImmediate(main)