Bufferput

Bufferput is a term used in programming to describe the operation of writing data into a pre-allocated memory buffer. It is not a standardized function in the sense of a language specification; instead, it appears in multiple codebases and libraries with similar semantics: place data into a buffer while respecting its size and the current write position.

Typically, a bufferput routine takes at least four elements: a destination buffer, a reference to the current write position (or an offset), the source data to write, and the length of data to write. The function writes up to the available space, updates the write position, and returns either the number of bytes actually written or an error code if there is insufficient space. The exact signature and return values vary by language and library, but the core idea is bounded, position-aware insertion into a buffer rather than unbounded copying.

Common usage patterns include building contiguous byte streams, serializing structures, or constructing messages in network or I/O code. Because the operation must respect bounds, bufferput implementations often perform explicit space checks before writing, and may provide safe wrappers to prevent buffer overruns. Some variants append to circular or ring buffers, where the write position wraps around after reaching the end.

Related terms include buffer_write, buffer_append, and similar helpers that provide controlled data insertion into buffers or streams. While the specifics of a bufferput function differ between projects, the core principle is consistent: append data into a fixed-size buffer while maintaining correct position tracking and error handling.