Computing is usually defined as the activity of using and improving computer hardware and software. It is the computer-specific part of information technology...
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
A computer terminal is an electronic or electromechanical hardware device that is used for entering data into, and displaying data from, a computer or a computing system...
Terminfo is a library and database that enables programs to use display terminals in a device-independent manner. This library has its origins in the UNIX System III operating system....
Termcap is a software library and database used on Unix-like computers. It enables programs to use display computer terminals in a device-independent manner, which greatly simplifies the process of writing portable text mode applications...
Environment variables are a set of dynamic named values that can affect the way running processes will behave on a computer.They can be said in some sense to create the operating environment in which a process runs...
Unix System V, commonly abbreviated SysV , is one of the first commercial versions of the Unix operating system. It was originally developed by American Telephone & Telegraph and first released in 1983. Four major versions of System V were released, termed Releases 1, 2, 3 and 4...
AT&T Inc. is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services...
tput was submitted to volume 7 of the mod.sources newsgroup (later comp.sources.unix) in September 1986. In contrast to the System V program, the clone used termcap rather than terminfo. It accepted command-line parameters for the cm (cursor addressing) capability, and recognized terminfo capability names.
System V Release 3 provided an improved version which combined the different initialization capabilities as a new option init, and the reset capabilities as reset, thereby simplifying use of tput for initializing or reinitializing the terminal. System V Release 3.2 added several printer-specific capabilities to the terminfo database, such as swidm (enter_doublewide_mode) which tput could use. It also added capabilities for color.
System V Release 4 defined additional terminfo capabilities including standardized ANSI color capabilities setaf and setab, which could be used by tput.
BSD platforms provided a different implementation of tput in 4.3BSD-Reno (June 1990). It used termcap, recognizing only termcap capability names, and did not accept command-line parameters for cursor-addressing. FreeBSD
FreeBSD
FreeBSD is a free Unix-like operating system descended from AT&T UNIX via BSD UNIX. Although for legal reasons FreeBSD cannot be called “UNIX”, as the direct descendant of BSD UNIX , FreeBSD’s internals and system APIs are UNIX-compliant...
used this in 1994, improving it by accepting one or two numeric command-line parameters.
Ross Ridge's mytinfo package in 1992 provided a tput which accepted either termcap or terminfo capability names. Like the Reno implementation, it did not pass command-line arguments to parameterized capabilities. ncurses
Ncurses
ncurses is a programming library that provides an API which allows the programmer to write text user interfaces in a terminal-independent manner. It is a toolkit for developing "GUI-like" application software that runs under a terminal emulator...
incorporated the mytinfo code in June 1995. The initial version added a -S option, and interpreted command-line parameters as described in the System V Release 4 documentation.
Portability
The Open Group defines one option (-T, to specify the terminal type) and three keywords (init, clear and reset).
Most implementations accept the name of a terminal capability together with any parameters that may be needed for that.
However, some implementations expect a termcap
Termcap
Termcap is a software library and database used on Unix-like computers. It enables programs to use display computer terminals in a device-independent manner, which greatly simplifies the process of writing portable text mode applications...
Terminfo is a library and database that enables programs to use display terminals in a device-independent manner. This library has its origins in the UNIX System III operating system....
name.
All System V Release 4 implementations, as well as those which are designed to be compatible, also recognize a -S option (to tell tput to read data from the standard input), and an additional keyword longname. They also accept command-line parameters, usually distinguishing numeric from string parameters by the form of the parameter, checking for all-numeric characters. That makes it impossible for example to set a function-key label to a string of digits. Using a different approach, ncurses determines the expected type of the parameters with a table of the terminfo capabilities which use string parameters, eliminating the ambiguity.
