Why C's standard integer parsing functions are broken

Summary

The article critiques the C standard library's integer parsing functions (atol(), strtol()/strtoul(), and sscanf()), arguing they are all fundamentally broken due to undefined behavior, inconsistent error handling, and ambiguous semantics. The author examines edge cases like overflow, invalid inputs, whitespace handling, and locale-dependent behavior, ultimately claiming there is no reliable, portable way to parse integers in C. A postscript update notes that C++'s std::from_chars() appears to be a useful alternative.