How to read one byte at a time?
When serialport.ReadByte() is called, it gets the ascii value for the character ‘a’, but doesn’t take the byte and doesn’t store it in the byte array. Can anyone tell me what is wrong in this code?
Table of Contents
How does the read function work in C?
read: From the file indicated by the file descriptor fd, the read() function reads cnt bytes of input into the area of memory indicated by buf. A successful read() updates the file access time. C language syntax size_t read (int fd, void* buf, size_t cnt); Parameters
Why does FD2 read the first byte of foobar.txt?
The fd1 and fd2 descriptors each have their own entry in the open files table, so each descriptor has its own file position for foobar.txt. Therefore, reading fd2 reads the first byte of foobar.txt and outputs c = f, not c = o.
If you want to read one byte at a time, call fread(&buffer, 1, 1, file); (See bread). But a simpler solution will be to declare an array of bytes, read them all together, and process them after that.
Is it possible to read byte by byte in Python?
Reading a file by bytes is a performance nightmare. This may not be the best solution available in python. This code should be used with care. – usr Jul 6 Not all scripts need optimal performance. — Skurme on Jul 08
How to iterate one byte at a time in Python?
In particular, you can iterate one byte at a time over a memory-mapped file just by using a simple for loop: mmap supports division notation. For example, mm [i:i+len] returns len bytes from the file starting at position i. The context manager protocol is not supported before Python 3.2; you need to call mm.close() explicitly in this case.
How to read a binary file and loop through each byte?
We will no longer be getting raw characters from the byte-mode stream, but byte objects, so we need to modify the condition: Or, as benhoyt says, omit what is not equal and take advantage of the fact that b”” evaluates to fake. This makes the code compatible between 2.6 and 3.x without any changes.
How are bytes represented as structures in Python?
This module performs conversions between Python values and C structures represented as Python byte objects. This can be used to handle binary data stored in files or from network connections, among other sources. It uses format strings as compact descriptions of the layout of C structures and the intended conversion to/from Python values.
How can I make a function that reads binary data into a structure?
How can I make a C++ function that reads a binary file, 128 bytes at a time, and loads each 128 bytes into a struct, and then makes a collection of those structs that can be used in a C# class? In other words, I want to be able to call this C++ function from C#.
How does struct interpret bytes as packed binary data?
The byte order character ‘=’ chooses to use big-endian or little-endian ordering depending on the host system. The struct module does not interpret this as a native sort, so the ‘P’ format is not available. The IEEE 754 binary16 “half-precision” type was introduced in the 2008 revision of the IEEE 754 standard.