tigetstr

tigetstr is a function from the terminfo library used by terminal handling in Unix-like systems. It retrieves the value of a string capability for the currently active terminal description, allowing programs to obtain control sequences defined in the terminfo database. The function is commonly used in conjunction with setupterm or curses-based applications to query terminal capabilities after the terminal database has been initialized.

The function takes a single argument, the name of the string capability to look up, such as "cup" (cursor movement), "clear" (screen clearing), or other terminal control sequences defined in the terminfo entry for the terminal. tigetstr returns a pointer to a string representing that capability for the current terminal. If the capability is not defined for the terminal, or if the terminfo data cannot be accessed, tigetstr returns NULL.

The string returned by tigetstr is typically a template that may require parameter substitution before use. For capabilities that require parameters, a separate function such as tparm is used to perform the substitution, producing a concrete sequence to send to the terminal. The returned string should not be modified or freed by the caller; it resides in a static area managed by the terminfo library and may be overwritten by subsequent calls.

tigetstr is part of the terminfo suite, and is related to other accessors such as tigetflag and tigetnum. It is available in environments using the ncurses library or other terminfo-compatible implementations. Proper use relies on an initial terminal database setup, typically via setupterm or an equivalent initialization routine, to ensure the terminal’s capabilities are loaded.