tparm

tparm is a function in the terminfo library used to expand parameterized terminal capability strings into concrete sequences for a terminal. It processes a string that encodes parameterized operations and substitutes provided numeric arguments to produce a terminal control sequence. The function is part of the terminfo API and is commonly used by terminal handling libraries such as ncurses. In practice, applications obtain a parameterized capability string (for example with tigetstr or tgetstr in termcap environments) and then apply tparm to it with numeric arguments corresponding to things like cursor positions or dimensions.

The typical signature in C is: char *tparm(char *str, long p1, long p2, long p3, long p4, long p5, long p6, long p7, long p8, long p9); It expands str using up to nine parameters and returns a pointer to a string containing the resulting sequence. The parameterized string uses the terminfo small programming language, which allows arithmetic, conditionals, and formatting to generate the final control sequence based on the supplied arguments.

Implementation details: tparm generally returns a pointer to a static buffer containing the expanded string. Because the buffer is shared across calls, callers should copy the result if they need to retain it beyond the next tparm invocation. This also means the function is not inherently thread-safe on many platforms.

See also: terminfo, ncurses, tigetstr, tgetstr, and tgoto. These facilities together enable portable generation of terminal control sequences from the terminfo database.