The Fn tgetent function extracts the entry for terminal Fa name into the buffer at Fa bp . The Fa bp argument should be a character buffer of size 1024 and must be retained through all subsequent calls to Fn tgetnum , Fn tgetflag , and Fn tgetstr . The Fn tgetent function returns -1 if none of the termcap data base files could be opened, 0 if the terminal name given does not have an entry, and 1 if all goes well. It will look in the environment for a TERMCAP variable. If found, and the value does not begin with a slash, and the terminal type Fa name is the same as the environment string TERM the TERMCAP string is used instead of reading a termcap file. If it does begin with a slash, the string is used as a path name of the termcap file to search. If TERMCAP does not begin with a slash and Fa name is different from TERM Fn tgetent searches the files $HOME/.termcap and /usr/share/misc/termcap in that order, unless the environment variable TERMPATH exists, in which case it specifies a list of file pathnames (separated by spaces or colons) to be searched instead. Whenever multiple files are searched and a tc field occurs in the requested entry, the entry it names must be found in the same file or one of the succeeding files. This can speed up entry into programs that call Fn tgetent , as well as help debug new terminal descriptions or make one for your terminal if you can't write the file /usr/share/misc/termcap
The Fn tgetnum function gets the numeric value of capability Fa id , returning -1 if it is not given for the terminal. The Fn tgetflag function returns 1 if the specified capability is present in the terminal's entry, 0 if it is not. The Fn tgetstr function returns the string value of the capability Fa id , places it in the buffer at Fa area , and advances the Fa area pointer. It decodes the abbreviations for this field described in termcap(5), except for cursor addressing and padding information. The Fn tgetstr function returns NULL if the capability was not found.
The Fn tgoto function returns a cursor addressing string decoded from Fa cm to go to column Fa destcol in line Fa destline . It uses the external variables UP (from the up capability) and BC (if bc is given rather than bs if necessary to avoid placing \n ^D or ^@ in the returned string. (Programs which call Fn tgoto should be sure to turn off the XTABS bit(s), since Fn tgoto may now output a tab. Note that programs using termcap should in general turn off XTABS anyway since some terminals use control-I for other functions, such as nondestructive space.) If a % sequence is given which is not understood, then Fn tgoto returns (OOPS )
The Fn tputs function decodes the leading padding information of the string Fa cp ; Fa affcnt gives the number of lines affected by the operation, or 1 if this is not applicable, Fa outc is a routine which is called with each character in turn. The external variable ospeed should contain the output speed of the terminal as encoded by stty(3). The external variable PC should contain a pad character to be used (from the capability) if a null (^@ ) is inappropriate.