How to use frida to hook a native function's arguments in Android?

[bxl0608]

Hello,Recent,I learn to use the frida framework，but i met a problem.
I have a native function, i know it has three argumens,fisrt is a Int, the second is String,i can print the first argument,but the second argument .i don't konw how to print it. code like this:

Interceptor.attach(Module.findExportByName("libuserinfo.so", "getString"),{
onEnter: function (args) {
send(args[2].toInt32()); // this is first argument.
// this.buf = args[3]; how can i print the second argument?
},
onLeave: function (retval) {

    }

});

[don1001]

is it ASCII string ? try

log(Memory.readUtf8String(args[3])); //log 4th argument

[oleavr]

Use Memory.readCString() if you're uncertain about the encoding. Use Memory.readUtf8String() if you're certain it's valid UTF-8 – otherwise it will throw a JS exception, whereas Memory.readCString() will try to decode as UTF-8, where bytes that can't be interpreted as valid Unicode are replaced with the Unicode replacement character. (Frida uses g_utf8_make_valid() behind the scenes.)