File I/O

2 articles

Linux 04 Sep 2026 8 min read

Write Files Atomically on Linux with rename and fsync

Updating a small file looks simple: open it, truncate it, write the new contents, and close it. That works when nothing interrupts the write. The failure mode appears when a process crashes, the machine loses power, or another process reads the file while it is being rewritten. A reader can observe an empty or partially written file, and a crash can leave the pathname referring to incomplete data. For configuration files, state snapshots, generated metadata, and similar single-file updates, a better pattern is to write a complete replacement beside the original file and then rename it into place.

Linux Filesystems

Python 04 Sep 2026 10 min read

Use Callable-Sentinel Iteration for Chunked Reads in Python

Reading a file in chunks is a small problem that appears in many larger tasks: hashing uploads, copying large files, parsing binary records, compressing streams, and sending data without loading everything into memory. A common solution is a while loop that reads one chunk, checks for end-of-file, processes the chunk, and repeats. That loop is correct when written carefully, but Python has another standard-library pattern that expresses the same control flow as iteration:

Python Iterators