X-Git-Url: http://ncurses.scripts.mit.edu/?p=ncurses.git;a=blobdiff_plain;f=doc%2Fhtml%2Fman%2Ftput.1.html;h=fcdaf71619ee4363a6e984769c972258ca8f5be4;hp=bbc22a4eeed642b453410eeb6c2c370ad3f71e57;hb=61790aa3ac9e0dff2b443ac567b174fc4d235b86;hpb=5606eb48618dde18a593793e2e5dafadf18d345b diff --git a/doc/html/man/tput.1.html b/doc/html/man/tput.1.html index bbc22a4e..fcdaf716 100644 --- a/doc/html/man/tput.1.html +++ b/doc/html/man/tput.1.html @@ -1,7 +1,8 @@ - + tput 1 - +

tput 1

-tput(1)                                                         tput(1)
+tput(1)                     General Commands Manual                    tput(1)
 
 
 
 
 

NAME

-       tput,  reset  -  initialize  a  terminal or query terminfo
-       database
+       tput, reset - initialize a terminal or query terminfo database
 
 
 

SYNOPSIS

        tput [-Ttype] capname [parameters]
-       tput [-Ttype] clear
+       tput [-Ttype] [-x] clear
        tput [-Ttype] init
        tput [-Ttype] reset
        tput [-Ttype] longname
@@ -62,164 +62,229 @@
 
 
 

DESCRIPTION

-       The tput utility uses the terminfo database  to  make  the
-       values  of terminal-dependent capabilities and information
-       available to the shell (see sh(1)), to initialize or reset
-       the  terminal,  or  return  the long name of the requested
-       terminal type.  The result depends upon  the  capability's
-       type:
+       The  tput  utility  uses  the  terminfo  database to make the values of
+       terminal-dependent capabilities and information available to the  shell
+       (see  sh(1)),  to  initialize or reset the terminal, or return the long
+       name of the requested terminal  type.   The  result  depends  upon  the
+       capability's type:
 
           string
-               tput writes the string to the standard output.  No
-               trailing newline is supplied.
+               tput  writes  the  string  to the standard output.  No trailing
+               newline is supplied.
 
           integer
-               tput writes the decimal value to the standard out-
-               put, with a trailing newline.
+               tput writes the decimal value to the standard  output,  with  a
+               trailing newline.
 
           boolean
-               tput  simply sets the exit code (0 for TRUE if the
-               terminal has the capability, 1  for  FALSE  if  it
-               does not), and writes nothing to the standard out-
-               put.
+               tput  simply sets the exit code (0 for TRUE if the terminal has
+               the capability, 1 for FALSE if it does not), and writes nothing
+               to the standard output.
 
-       Before using a value returned on the standard output,  the
-       application  should  test  the  exit  code  (e.g., $?, see
-       sh(1)) to be sure it is 0.  (See the EXIT CODES and  DIAG-
-       NOSTICS  sections.)   For  a complete list of capabilities
-       and the capname associated with each, see terminfo(5).
+       Before  using  a value returned on the standard output, the application
+       should test the exit code (e.g., $?, see sh(1)) to be  sure  it  is  0.
+       (See  the EXIT CODES and DIAGNOSTICS sections.)  For a complete list of
+       capabilities and the capname associated with each, see terminfo(5).
 
 
 

Options

-       -Ttype indicates the  type  of  terminal.   Normally  this
-              option is unnecessary, because the default is taken
-              from the environment variable TERM.  If -T is spec-
-              ified,  then  the shell variables LINES and COLUMNS
-              will also be ignored.
+       -S     allows more than one capability per  invocation  of  tput.   The
+              capabilities  must  be  passed  to  tput from the standard input
+              instead of from  the  command  line  (see  example).   Only  one
+              capname  is allowed per line.  The -S option changes the meaning
+              of the 0 and 1 boolean and string exit codes (see the EXIT CODES
+              section).
 
-       -S     allows more than one capability per  invocation  of
-              tput.  The capabilities must be passed to tput from
-              the standard input instead of from the command line
-              (see  example).   Only  one  capname is allowed per
-              line.  The -S option changes the meaning of  the  0
-              and  1  boolean and string exit codes (see the EXIT
-              CODES section).
+              Because  some capabilities may use string parameters rather than
+              numbers, tput uses a table and the presence of parameters in its
+              input  to  decide whether to use tparm(3x), and how to interpret
+              the parameters.
 
-              Again, tput uses a table and the presence of param-
-              eters  in  its  input  to  decide  whether  to  use
-              tparm(3x), and how to interpret the parameters.
+       -Ttype indicates  the  type  of  terminal.   Normally  this  option  is
+              unnecessary,  because  the default is taken from the environment
+              variable TERM.  If -T is specified,  then  the  shell  variables
+              LINES and COLUMNS will also be ignored.
 
-       -V     reports the version of ncurses which  was  used  in
-              this program, and exits.
+       -V     reports  the  version of ncurses which was used in this program,
+              and exits.
+
+       -x     do not attempt to clear the terminal's scrollback  buffer  using
+              the extended "E3" capability.
 
 
 

Commands

+       A few commands (init, reset and longname) are special; they are defined
+       by the tput program.  The others are the names of capabilities from the
+       terminal  database  (see  terminfo(5)  for  a list).  Although init and
+       reset resemble capability names,  tput  uses  several  capabilities  to
+       perform these special functions.
+
        capname
-              indicates  the  capability  from the terminfo data-
-              base.  When termcap support  is  compiled  in,  the
-              termcap name for the capability is also accepted.
-
-              If  the  capability  is a string that takes parame-
-              ters, the arguments following the  capability  will
-              be used as parameters for the string.
-
-              Most  parameters  are numbers.  Only a few terminfo
-              capabilities require string parameters; tput uses a
-              table to decide which to pass as strings.  Normally
-              tput uses tparm(3x) to  perform  the  substitution.
-              If no parameters are given for the capability, tput
-              writes the string without performing the  substitu-
-              tion.
-
-       init   If  the  terminfo  database is present and an entry
-              for the user's terminal exists (see -Ttype, above),
-              the following will occur:
-
-              (1)  if   present,  the  terminal's  initialization
-                   strings will be output as detailed in the ter-
-                   minfo(5) section on Tabs and Initialization,
-
-              (2)  any  delays  (e.g.,  newline) specified in the
-                   entry will be set in the tty driver,
-
-              (3)  tabs  expansion  will  be  turned  on  or  off
-                   according  to  the specification in the entry,
-                   and
-
-              (4)  if tabs are not expanded, standard  tabs  will
-                   be set (every 8 spaces).
-
-              If an entry does not contain the information needed
-              for any of these  activities,  that  activity  will
-              silently be skipped.
-
-       reset  Instead  of putting out initialization strings, the
-              terminal's reset strings will be output if  present
-              (rs1,  rs2, rs3, rf).  If the reset strings are not
-              present, but initialization strings are,  the  ini-
-              tialization  strings  will  be  output.  Otherwise,
-              reset acts identically to init.
+              indicates the capability from the terminal database.
+
+              If  the  capability  is  a  string  that  takes  parameters, the
+              arguments following the capability will be  used  as  parameters
+              for the string.
+
+              Most  parameters  are numbers.  Only a few terminal capabilities
+              require string parameters; tput uses a table to decide which  to
+              pass  as  strings.   Normally tput uses tparm(3x) to perform the
+              substitution.  If no parameters are given  for  the  capability,
+              tput writes the string without performing the substitution.
+
+       init   If  the terminal database is present and an entry for the user's
+              terminal exists (see -Ttype, above), the following will occur:
+
+              (1)  first, tput retrieves the current  terminal  mode  settings
+                   for your terminal.  It does this by successively testing
+
+                   o   the standard error,
+
+                   o   standard output,
+
+                   o   standard input and
+
+                   o   ultimately "/dev/tty"
+
+                   to   obtain  terminal  settings.   Having  retrieved  these
+                   settings, tput remembers which file descriptor to use  when
+                   updating settings.
+
+              (2)  if  the  window  size cannot be obtained from the operating
+                   system, but the terminal description (or environment, e.g.,
+                   LINES  and  COLUMNS  variables  specify  this),  update the
+                   operating system's notion of the window size.
+
+              (3)  the terminal modes will be updated:
+
+                   o   any delays (e.g., newline) specified in the entry  will
+                       be set in the tty driver,
+
+                   o   tabs  expansion  will  be turned on or off according to
+                       the specification in the entry, and
+
+                   o   if tabs are not expanded, standard  tabs  will  be  set
+                       (every 8 spaces).
+
+              (4)  if  present,  the terminal's initialization strings will be
+                   output as detailed in the terminfo(5) section on  Tabs  and
+                   Initialization,
+
+              (5)  output is flushed.
+
+              If  an  entry does not contain the information needed for any of
+              these activities, that activity will silently be skipped.
+
+       reset  This is similar to init, with two differences:
+
+              (1)  before any other initialization, the terminal modes will be
+                   reset to a "sane" state:
+
+                   o   set cooked and echo modes,
+
+                   o   turn off cbreak and raw modes,
+
+                   o   turn on newline translation and
+
+                   o   reset  any  unset  special  characters to their default
+                       values
+
+              (2)  Instead  of  putting  out   initialization   strings,   the
+                   terminal's  reset  strings  will be output if present (rs1,
+                   rs2, rs3, rf).  If the reset strings are not  present,  but
+                   initialization strings are, the initialization strings will
+                   be output.
+
+              Otherwise, reset acts identically to init.
 
        longname
-              If the terminfo database is present  and  an  entry
-              for  the user's terminal exists (see -Ttype above),
-              then the long name of the terminal will be put out.
-              The long name is the last name in the first line of
-              the terminal's description in the terminfo database
-              [see term(5)].
+              If the terminal database is present and an entry for the  user's
+              terminal  exists  (see  -Ttype above), then the long name of the
+              terminal will be put out.  The long name is the last name in the
+              first  line  of  the  terminal's  description  in  the  terminfo
+              database [see term(5)].
 
 
 

Aliases

-       tput handles the clear, init and reset commands specially:
-       it allows for the possibility that it is invoked by a link
-       with those names.
+       tput handles the clear, init and reset commands  specially:  it  allows
+       for the possibility that it is invoked by a link with those names.
+
+       If  tput  is invoked by a link named reset, this has the same effect as
+       tput reset.  The  tset(1)  utility  also  treats  a  link  named  reset
+       specially.
+
+       Before ncurses 6.1, the two utilities were different from each other:
 
-       If  tput  is  invoked  by a link named reset, this has the
-       same effect as  tput  reset.   The  tset(1)  utility  also
-       treats a link named reset specially.
+       o   tset  utility  reset the terminal modes and special characters (not
+           done with tput).
 
-       Before  ncurses 6.1, the two utilities were different from
-       each other:
+       o   On the other hand, tset's repertoire of terminal  capabilities  for
+           resetting  the terminal was more limited, i.e., only reset_1string,
+           reset_2string and reset_file  in  contrast  to  the  tab-stops  and
+           margins which are set by this utility.
 
-       o   tset utility reset  the  terminal  modes  and  special
-           characters (not done with tput).
+       o   The  reset  program  is  usually an alias for tset, because of this
+           difference with resetting terminal modes and special characters.
 
-       o   On the other hand, tset's repertoire of terminal capa-
-           bilities for resetting the terminal was more  limited,
-           i.e., only reset_1string, reset_2string and reset_file
-           in contrast to the tab-stops and margins which are set
-           by this utility.
+       With the changes made for ncurses 6.1, the reset  feature  of  the  two
+       programs is (mostly) the same.  A few differences remain:
 
-       o   The  reset  program  is  usually  an  alias  for tset,
-           because of this  difference  with  resetting  terminal
-           modes and special characters.
+       o   The  tset  program  waits  one  second  when  resetting, in case it
+           happens to be a hardware terminal.
 
-       If tput is invoked by a link named init, this has the same
-       effect as tput init.  Again, you are less  likely  to  use
-       that  link  because  another program named init has a more
-       well-established use.
+       o   The two programs  write  the  terminal  initialization  strings  to
+           different  streams  (i.e.,  the  standard  error  for  tset and the
+           standard output for tput).
+
+           Note:  although  these  programs  write   to   different   streams,
+           redirecting  their output to a file will capture only part of their
+           actions.  The changes to the terminal modes  are  not  affected  by
+           redirecting the output.
+
+       If  tput  is  invoked by a link named init, this has the same effect as
+       tput init.  Again, you are less likely to use that link because another
+       program named init has a more well-established use.
+
+
+

Terminal Size

+       Besides  the  special  commands  (e.g.,  clear),  tput  treats  certain
+       terminfo  capabilities  specially:  lines   and   cols.    tput   calls
+       setupterm(3x) to obtain the terminal size:
+
+       o   first, it gets the size from the terminal database (which generally
+           is not provided for terminal emulators which do not  have  a  fixed
+           window size)
+
+       o   then  it  asks  the operating system for the terminal's size (which
+           generally works, unless connecting via a serial line which does not
+           support NAWS: negotiations about window size).
+
+       o   finally,  it  inspects  the environment variables LINES and COLUMNS
+           which may override the terminal size.
+
+       If the -T option is given tput ignores  the  environment  variables  by
+       calling   use_tioctl(TRUE),  relying  upon  the  operating  system  (or
+       finally, the terminal database).
 
 
 

EXAMPLES

        tput init
-            Initialize the terminal according to the type of ter-
-            minal  in the environmental variable TERM.  This com-
-            mand should be included in everyone's .profile  after
-            the environmental variable TERM has been exported, as
-            illustrated on the profile(5) manual page.
+            Initialize the terminal according to the type of terminal  in  the
+            environmental  variable  TERM.  This command should be included in
+            everyone's .profile after the environmental variable TERM has been
+            exported, as illustrated on the profile(5) manual page.
 
        tput -T5620 reset
-            Reset an AT&T 5620 terminal, overriding the  type  of
-            terminal in the environmental variable TERM.
+            Reset  an  AT&T  5620 terminal, overriding the type of terminal in
+            the environmental variable TERM.
 
        tput cup 0 0
-            Send the sequence to move the cursor to row 0, column
-            0 (the upper left corner of the screen, usually known
-            as the "home" cursor position).
+            Send the sequence to move the cursor to row 0, column 0 (the upper
+            left  corner  of  the  screen,  usually known as the "home" cursor
+            position).
 
        tput clear
-            Echo the clear-screen sequence for the current termi-
-            nal.
+            Echo the clear-screen sequence for the current terminal.
 
        tput cols
             Print the number of columns for the current terminal.
@@ -228,28 +293,25 @@
             Print the number of columns for the 450 terminal.
 
        bold=`tput smso` offbold=`tput rmso`
-            Set the shell variables bold, to begin stand-out mode
-            sequence, and offbold, to end standout mode sequence,
-            for the current terminal.  This might be followed  by
-            a  prompt:  echo  "${bold}Please  type  in your name:
-            ${offbold}\c"
+            Set the shell variables bold, to begin  stand-out  mode  sequence,
+            and  offbold,  to  end  standout  mode  sequence,  for the current
+            terminal.  This might be followed by a prompt: echo "${bold}Please
+            type in your name: ${offbold}\c"
 
        tput hc
-            Set exit code to indicate if the current terminal  is
-            a hard copy terminal.
+            Set  exit  code to indicate if the current terminal is a hard copy
+            terminal.
 
        tput cup 23 4
-            Send  the sequence to move the cursor to row 23, col-
-            umn 4.
+            Send the sequence to move the cursor to row 23, column 4.
 
        tput cup
-            Send the terminfo string for cursor-movement, with no
-            parameters substituted.
+            Send the terminfo string for cursor-movement, with  no  parameters
+            substituted.
 
        tput longname
-            Print  the  long  name from the terminfo database for
-            the type of terminal specified in  the  environmental
-            variable TERM.
+            Print  the  long  name  from the terminfo database for the type of
+            terminal specified in the environmental variable TERM.
 
             tput -S <<!
             > clear
@@ -257,11 +319,10 @@
             > bold
             > !
 
-            This  example shows tput processing several capabili-
-            ties in one invocation.  It clears the screen,  moves
-            the  cursor  to  position  10,  10  and turns on bold
-            (extra bright) mode.  The list is  terminated  by  an
-            exclamation mark (!) on a line by itself.
+            This example shows tput processing  several  capabilities  in  one
+            invocation.   It  clears  the screen, moves the cursor to position
+            10, 10 and turns  on  bold  (extra  bright)  mode.   The  list  is
+            terminated by an exclamation mark (!) on a line by itself.
 
 
 

FILES

@@ -269,51 +330,45 @@
               compiled terminal description database
 
        /usr/share/tabset/*
-              tab settings for some terminals, in a format appro-
-              priate  to  be  output  to  the  terminal   (escape
-              sequences  that  set  margins  and  tabs); for more
-              information, see the Tabs and Initialization,  sec-
-              tion of terminfo(5)
+              tab  settings  for some terminals, in a format appropriate to be
+              output to the terminal (escape sequences that  set  margins  and
+              tabs);  for  more  information, see the Tabs and Initialization,
+              section of terminfo(5)
 
 
 

EXIT CODES

-       If the -S option is used, tput checks for errors from each
-       line, and if any errors are found, will set the exit  code
-       to  4  plus the number of lines with errors.  If no errors
-       are found, the exit code is 0.   No  indication  of  which
-       line failed can be given so exit code 1 will never appear.
-       Exit codes 2, 3, and 4 retain their usual  interpretation.
-       If the -S option is not used, the exit code depends on the
-       type of capname:
+       If the -S option is used, tput checks for errors from each line, and if
+       any  errors  are  found, will set the exit code to 4 plus the number of
+       lines with errors.  If no errors are found, the exit  code  is  0.   No
+       indication  of which line failed can be given so exit code 1 will never
+       appear.  Exit codes 2, 3, and 4 retain their usual interpretation.   If
+       the  -S  option  is  not  used,  the  exit  code depends on the type of
+       capname:
 
           boolean
                  a value of 0 is set for TRUE and 1 for FALSE.
 
-          string a value of 0 is set if the  capname  is  defined
-                 for  this terminal type (the value of capname is
-                 returned on standard output); a value  of  1  is
-                 set  if capname is not defined for this terminal
-                 type (nothing is written to standard output).
+          string a value of 0 is set  if  the  capname  is  defined  for  this
+                 terminal  type  (the value of capname is returned on standard
+                 output); a value of 1 is set if capname is  not  defined  for
+                 this terminal type (nothing is written to standard output).
 
           integer
-                 a value of 0 is always set, whether or not  cap-
-                 name  is  defined  for  this  terminal type.  To
-                 determine if capname is defined for this  termi-
-                 nal  type,  the user must test the value written
-                 to standard output.  A value of  -1  means  that
-                 capname is not defined for this terminal type.
+                 a value of 0 is always set, whether or not capname is defined
+                 for this terminal type.  To determine if capname  is  defined
+                 for  this terminal type, the user must test the value written
+                 to standard output.  A value of -1 means that capname is  not
+                 defined for this terminal type.
 
-          other  reset  or init may fail to find their respective
-                 files.  In that case, the exit code is set to  4
-                 + errno.
+          other  reset  or  init  may fail to find their respective files.  In
+                 that case, the exit code is set to 4 + errno.
 
-       Any  other  exit code indicates an error; see the DIAGNOS-
-       TICS section.
+       Any other exit code indicates an error; see the DIAGNOSTICS section.
 
 
 

DIAGNOSTICS

-       tput prints the following error messages and sets the cor-
-       responding exit codes.
+       tput prints the following error messages  and  sets  the  corresponding
+       exit codes.
 
        exit code   error message
        ---------------------------------------------------------------------
@@ -329,123 +384,150 @@
 
 
 

HISTORY

-       The  tput command was begun by Bill Joy in 1980.  The ini-
-       tial version only cleared the screen.
+       The  tput  command  was begun by Bill Joy in 1980.  The initial version
+       only cleared the screen.
+
+       AT&T System V provided a different tput command, whose init  and  reset
+       subcommands  (more  than  half  the program) were incorporated from the
+       reset feature of BSD tset written by Eric Allman.
 
-       AT&T System V provided a  different  tput  command,  whose
-       init  and  reset  subcommands (more than half the program)
-       were incorporated from the reset feature of BSD tset writ-
-       ten  by  Eric Allman.  Later the corresponding source code
-       for reset was removed from the BSD  tset  (in  June  1993,
-       released in 4.4BSD-Lite a year later).
+       Keith Bostic  replaced  the  BSD  tput  command  in  1989  with  a  new
+       implementation  based on the AT&T System V program tput.  Like the AT&T
+       program, Bostic's version accepted some parameters named  for  terminfo
+       capabilities  (clear,  init,  longname and reset).  However (because he
+       had only termcap  available),  it  accepted  termcap  names  for  other
+       capabilities.   Also, Bostic's BSD tput did not modify the terminal I/O
+       modes as the earlier BSD tset had done.
 
-       Keith  Bostic replaced the BSD tput command in 1989 with a
-       new implementation based on  the  AT&T  System  V  program
-       tput.   Like  the  AT&T program, Bostic's version accepted
-       some parameters named for  terminfo  capabilities  (clear,
-       init,  longname  and reset).  However (because he had only
-       termcap available), it accepted termcap  names  for  other
-       capabilities.   Also, Bostic's BSD tput did not modify the
-       terminal I/O modes as the earlier BSD tset had done.
+       At the same time, Bostic added a shell script named "clear", which used
+       tput to clear the screen.
 
-       At the same  time,  Bostic  added  a  shell  script  named
-       "clear", which used tput to clear the screen.
+       Both   of   these   appeared  in  4.4BSD,  becoming  the  "modern"  BSD
+       implementation of tput.
 
-       Both  of  these  appeared in 4.4BSD, becoming the "modern"
-       BSD implementation of tput.
+       This implementation of tput began from a different source than AT&T  or
+       BSD:  Ross  Ridge's  mytinfo package, published on comp.sources.unix in
+       December 1992.  Ridge's program made  more  sophisticated  use  of  the
+       terminal  capabilities  than  the  BSD program.  Eric Raymond used that
+       tput program (and other parts of mytinfo)  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.
 
 
 

PORTABILITY

-       This implementation of tput differs from AT&T tput in  two
-       important areas:
-
-       o   tput capname 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 init and reset commands  use
-           the BSD (4.1c) tset 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, tput did not
-           modify  terminal  modes.   tput  now  uses  a  similar
-           scheme,  using  functions  shared with tset (and ulti-
-           mately based on the 4.4BSD tset).  If it is  not  able
-           to  open  a terminal, e.g., when running in cron, tput
-           will return an error.
-
-       o   AT&T tput guesses the type of its capname operands  by
-           seeing if all of the characters are numeric, or not.
-
-           Most implementations which provide support for capname
-           operands use the tparm function to  expand  parameters
-           in it.  That function expects a mixture of numeric and
-           string parameters, requiring tput to know  which  type
-           to use.
-
-           This  implementation  uses  a  table  to determine the
-           parameter types for the standard capname operands, and
-           an  internal  library  function to analyze nonstandard
-           capname operands.
-
-       The longname and -S options, and  the  parameter-substitu-
-       tion  features used in the cup example, were not supported
-       in BSD curses before 4.3reno (1989) or in AT&T/USL  curses
-       before SVr4 (1988).
-
-       IEEE  Std 1003.1/The Open Group  Base Specifications Issue
-       7 (POSIX.1-2008) documents only the  operands  for  clear,
-       init  and reset.  There are a few interesting observations
-       to make regarding that:
-
-       o   In this implementation, clear is part of  the  capname
-           support.  The others (init and longname) do not corre-
-           spond to terminal capabilities.
-
-       o   Other implementations of tput  on  SVr4-based  systems
-           such  as  Solaris,  IRIX64  and HPUX as well as others
-           such as AIX and Tru64 provide support for capname  op-
-           erands.
-
-       o   A  few  platforms  such  as  FreeBSD recognize termcap
-           names rather than terminfo capability names  in  their
-           respective  tput  commands.  Since 2010, NetBSD's tput
-           uses terminfo names.  Before that, it  (like  FreeBSD)
-           recognized termcap names.
-
-       Because  (apparently)  all  of  the certified Unix systems
-       support the full set of capability  names,  the  reasoning
-       for documenting only a few may not be apparent.
-
-       o   X/Open Curses Issue 7 documents tput differently, with
-           capname and the other features used in this  implemen-
-           tation.
-
-       o   That  is,  there  are two standards for tput: POSIX (a
-           subset) and X/Open Curses (the  full  implementation).
-           POSIX  documents a subset to avoid the complication of
-           including X/Open Curses and the terminal  capabilities
-           database.
-
-       o   While it is certainly possible to write a tput program
-           without using curses, none of the systems which have a
-           curses  implementation  provide  a  tput utility which
-           does not provide the capname feature.
+       This  implementation  of  tput  differs from AT&T tput in two important
+       areas:
+
+       o   tput capname writes to the standard output.  That  need  not  be  a
+           regular   terminal.   However,  the  subcommands  which  manipulate
+           terminal modes may not use the standard output.
+
+           The AT&T implementation's init  and  reset  commands  use  the  BSD
+           (4.1c)   tset   source,   which  manipulates  terminal  modes.   It
+           successively tries standard output, standard 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, tput did not modify  terminal
+           modes.  tput now uses a similar scheme, using functions shared with
+           tset (and ultimately based on the 4.4BSD tset).  If it is not  able
+           to open a terminal, e.g., when running in cron, tput will return an
+           error.
+
+       o   AT&T tput guesses the type of its capname operands by seeing if all
+           of the characters are numeric, or not.
+
+           Most implementations which provide support for capname operands use
+           the tparm function to  expand  parameters  in  it.   That  function
+           expects  a mixture of numeric and string parameters, requiring tput
+           to know which type to use.
+
+           This implementation uses a table to determine the  parameter  types
+           for the standard capname operands, and an internal library function
+           to analyze nonstandard capname operands.
+
+       This  implementation  (unlike  others)  can  accept  both  termcap  and
+       terminfo  names for the capname feature, if termcap support is compiled
+       in.  However, the  predefined  termcap  and  terminfo  names  have  two
+       ambiguities in this case (and the terminfo name is assumed):
+
+       o   The  termcap  name  dl corresponds to the terminfo name dl1 (delete
+           one line).
+           The terminfo name dl corresponds to the termcap name DL  (delete  a
+           given number of lines).
+
+       o   The  termcap  name  ed  corresponds  to the terminfo name rmdc (end
+           delete mode).
+           The terminfo name ed corresponds to the termcap name cd  (clear  to
+           end of screen).
+
+       The  longname  and  -S options, and the parameter-substitution features
+       used in the cup example,  were  not  supported  in  BSD  curses  before
+       4.3reno (1989) or in AT&T/USL curses before SVr4 (1988).
+
+       IEEE   Std   1003.1/The   Open   Group   Base  Specifications  Issue  7
+       (POSIX.1-2008) documents only the operands for clear, init  and  reset.
+       There are a few interesting observations to make regarding that:
+
+       o   In  this implementation, clear is part of the capname support.  The
+           others  (init  and  longname)  do  not   correspond   to   terminal
+           capabilities.
+
+       o   Other  implementations  of  tput  on  SVr4-based  systems  such  as
+           Solaris, IRIX64 and HPUX as well as others such as  AIX  and  Tru64
+           provide support for capname operands.
+
+       o   A few platforms such as FreeBSD recognize termcap names rather than
+           terminfo capability names in their respective tput commands.  Since
+           2010,  NetBSD's  tput  uses  terminfo names.  Before that, it (like
+           FreeBSD) recognized termcap names.
+
+       Because (apparently) all of the certified Unix systems support the full
+       set  of  capability names, the reasoning for documenting only a few may
+       not be apparent.
+
+       o   X/Open Curses Issue 7 documents tput differently, with capname  and
+           the other features used in this implementation.
+
+       o   That  is,  there  are  two standards for tput: POSIX (a subset) and
+           X/Open Curses (the full implementation).  POSIX documents a  subset
+           to  avoid  the  complication  of  including  X/Open  Curses and the
+           terminal capabilities database.
+
+       o   While it is certainly possible to  write  a  tput  program  without
+           using   curses,   none   of   the   systems  which  have  a  curses
+           implementation provide a tput utility which does  not  provide  the
+           capname feature.
+
+       X/Open  Curses  Issue  7  (2009)  is  the  first  version  to  document
+       utilities.  However that part of X/Open Curses does not follow existing
+       practice (i.e., Unix features documented in SVID 3):
+
+       o   It  assigns exit code 4 to "invalid operand", which may be the same
+           as unknown capability.  For instance, the source code for  Solaris'
+           xcurses uses the term "invalid" in this case.
+
+       o   It  assigns  exit  code  255  to  a  numeric  variable  that is not
+           specified in the terminfo database.  That likely is a documentation
+           error,  confusing  the  -1  written  to  the standard output for an
+           absent or cancelled numeric value versus an (unsigned) exit code.
+
+       The various Unix systems (AIX, HPUX, Solaris) use the  same  exit-codes
+       as ncurses.
+
+       NetBSD curses documents different exit codes which do not correspond to
+       either ncurses or X/Open.
 
 
 

SEE ALSO

-       clear(1),   stty(1),   tabs(1),   tset(1),    terminfo(5),
-       curs_termcap(3x).
+       clear(1), stty(1), tabs(1), tset(1), curs_termcap(3x), terminfo(5).
 
-       This describes ncurses version 6.0 (patch 20161119).
+       This describes ncurses version 6.2 (patch 20210102).
 
 
 
-                                                                tput(1)
+                                                                       tput(1)