+</PRE><H2><a name="h2-HISTORY">HISTORY</a></H2><PRE>
+ The <STRONG>tput</STRONG> command was begun by Bill Joy in 1980. The ini-
+ tial version only cleared the screen.
+
+ AT&T System V provided a different <STRONG>tput</STRONG> command, whose
+ <STRONG>init</STRONG> and <STRONG>reset</STRONG> subcommands (more than half the program)
+ were incorporated from the <STRONG>reset</STRONG> feature of BSD <STRONG>tset</STRONG> writ-
+ ten by Eric Allman.
+
+ Keith Bostic replaced the BSD <STRONG>tput</STRONG> command in 1989 with a
+ new implementation based on the AT&T System V program
+ <STRONG>tput</STRONG>. Like the AT&T program, Bostic's version accepted
+ some parameters named for <EM>terminfo</EM> <EM>capabilities</EM> (<STRONG>clear</STRONG>,
+ <STRONG>init</STRONG>, <STRONG>longname</STRONG> and <STRONG>reset</STRONG>). However (because he had only
+ termcap available), it accepted <EM>termcap</EM> <EM>names</EM> for other
+ capabilities. Also, Bostic's BSD <STRONG>tput</STRONG> did not modify the
+ terminal I/O modes as the earlier BSD <STRONG>tset</STRONG> had done.
+
+ At the same time, Bostic added a shell script named
+ "clear", which used <STRONG>tput</STRONG> to clear the screen.
+
+ Both of these appeared in 4.4BSD, becoming the "modern"
+ BSD implementation of <STRONG>tput</STRONG>.
+
+ This implementation of <STRONG>tput</STRONG> began from a different source
+ than AT&T or BSD: Ross Ridge's <EM>mytinfo</EM> package, published
+ on <EM>comp.sources.unix</EM> in December 1992. Ridge's program
+ made more sophisticated use of the terminal capabilities
+ than the BSD program. Eric Raymond used the <STRONG>tput</STRONG> program
+ (and other parts of <EM>mytinfo</EM>) in ncurses in June 1995.
+ Using the portions dealing with terminal capabilities
+ almost without change, Raymond made improvements to the
+ way the command-line parameters were handled.
+
+
+</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
+ This implementation of <STRONG>tput</STRONG> differs from AT&T <STRONG>tput</STRONG> in two
+ important areas:
+
+ <STRONG>o</STRONG> <STRONG>tput</STRONG> <EM>capname</EM> writes to the standard output. That need
+ not be a regular terminal. However, the subcommands
+ which manipulate terminal modes may not use the stan-
+ dard output.
+
+ The AT&T implementation's <STRONG>init</STRONG> and <STRONG>reset</STRONG> commands use
+ the BSD (4.1c) <STRONG>tset</STRONG> source, which manipulates terminal
+ modes. It successively tries standard output, stan-
+ dard error, standard input before falling back to
+ "/dev/tty" and finally just assumes a 1200Bd terminal.
+ When updating terminal modes, it ignores errors.
+
+ Until changes made after ncurses 6.0, <STRONG>tput</STRONG> did not
+ modify terminal modes. <STRONG>tput</STRONG> now uses a similar
+ scheme, using functions shared with <STRONG>tset</STRONG> (and ulti-
+ mately based on the 4.4BSD <STRONG>tset</STRONG>). If it is not able
+ to open a terminal, e.g., when running in <STRONG>cron</STRONG>, <STRONG>tput</STRONG>
+ will return an error.
+
+ <STRONG>o</STRONG> AT&T <STRONG>tput</STRONG> guesses the type of its <EM>capname</EM> operands by
+ seeing if all of the characters are numeric, or not.
+
+ Most implementations which provide support for <EM>capname</EM>
+ operands use the <EM>tparm</EM> function to expand parameters
+ in it. That function expects a mixture of numeric and
+ string parameters, requiring <STRONG>tput</STRONG> to know which type
+ to use.
+
+ This implementation uses a table to determine the
+ parameter types for the standard <EM>capname</EM> operands, and
+ an internal library function to analyze nonstandard
+ <EM>capname</EM> operands.
+
+ This implementation (unlike others) can accept both <EM>term-</EM>
+ <EM>cap</EM> and <EM>terminfo</EM> names for the <EM>capname</EM> feature, if <EM>termcap</EM>
+ support is compiled in. However, the predefined <EM>termcap</EM>
+ and <EM>terminfo</EM> names have two ambiguities in this case (and
+ the <EM>terminfo</EM> name is assumed):
+
+ <STRONG>o</STRONG> The <EM>termcap</EM> name <STRONG>dl</STRONG> corresponds to the <EM>terminfo</EM> name
+ <STRONG>dl1</STRONG> (delete one line).
+ The <EM>terminfo</EM> name <STRONG>dl</STRONG> corresponds to the <EM>termcap</EM> name
+ <STRONG>DL</STRONG> (delete a given number of lines).
+
+ <STRONG>o</STRONG> The <EM>termcap</EM> name <STRONG>ed</STRONG> corresponds to the <EM>terminfo</EM> name
+ <STRONG>rmdc</STRONG> (end delete mode).
+ The <EM>terminfo</EM> name <STRONG>ed</STRONG> corresponds to the <EM>termcap</EM> name
+ <STRONG>cd</STRONG> (clear to end of screen).
+