YAP(1)							      General Commands Manual							    YAP(1)

NAME

       yap, more - yet another pager

SYNOPSIS

       yap [ -cnuq ] [ -n ] [ +command ] [ name ...  ]

DESCRIPTION

       Yap is a program allowing the user to examine a continuous text one screenful at a time on a video display terminal.  It does so by pausing
       after each screenful, waiting for the user to type a command.  The commands are enumerated later.  Yap's main feature is, that it can  page
       both forwards and backwards, even when reading from standard input.

       The command line options are:

       -n     An integer which is the size (in lines) of a page (the initial page-size.

       -c     Normally,  yap  will display each page by beginning at the top of the screen and erasing each line just before it displays on it. If
	      your terminal cannot erase a line, yap will clear the screen before it displays a page.
	      This avoids scrolling the screen, making it easier to read while yap is writing.	The -c option causes  yap  to  scroll  the  screen
	      instead of beginning at the top of the screen.  This is also done if your terminal cannot either erase a line or clear the screen.

       -u     Normally,  yap handles underlining such as produced by nroff in a manner appropriate to the particular terminal: if the terminal can
	      perform underlining well (t.i., the escape sequences for underlining do not occupy space on the screen), yap will  underline  under-
	      lined information in the input. The -u option supresses this underlining.

       -n     Normally,  yap  also recognises escape sequences for stand-out mode or underlining mode in the input, and knows how much space these
	      escape sequences will occupy on the screen, so that yap will not fold lines erroneously.	 The  -n  option  supresses  this  pattern
	      matching.

       -q     This option will cause yap to exit only on the "quit" command.

       +command
	      command is taken to be an initial command to yap.

       Yap uses the termcap(5) database to determine the terminal capabilities and the default page-size.  It examines the $TERM environment vari-
       able to identify the terminal type.  If $TERM is not set, it defaults to dumb.  Yap Also examines  the  $TERMCAP  environment  variable	to
       locate the termcap(5) database.	If $TERMCAP is not set, it defaults to /etc/termcap.

       Yap looks in the $YAP environment variable to pre-set flags.  For instance, if you prefer the -c mode of operation, just set the $YAP envi-
       ronment variable to -c.

       The commands of yap can be bound to sequences of keystrokes.  The environment variable $YAPKEYS may contain the bindings in the form  of  a
       list of colon-separated `name=sequence' pairs.  The name is a short mnemonic for the command, the sequence is the sequence of keystrokes to
       be typed to invoke the command.	This sequence may contain a ^X escape, which means control-X, and a X escape, which means X.  The  latter
       can  be	used  to get the characters `^', `' and `:' in the sequence.  There are two keymaps available, the default one and a user-defined
       one.  You can switch between one and the other with the change keymap command.

       The yap commands are described below.  The mnemonics for the commands are given in parentheses. The default  key  sequences  (if  any)  are
       given  after  the  mnemonic.   Every  command takes an optional integer argument, which may be typed before the command. Some commands just
       ignore it. The integer argument is referred to as i.  Usually, if i is not given, it defaults to 1.

       visit previous file (bf) P
	      Visit the i-th previous file given in the command line.

       scroll one line up or go to line (bl) ^K or k
	      If i is not given, scroll one line up. Otherwise, i will be interpreted as a line number. A page starting with  the  line  indicated
	      will then be displayed.

       bottom (bot) l or $
	      Go to the last line of the input.

       display previous page (bp) -
	      Display the previous page, consisting of i lines, (or page-size lines if no argument is given).

       display previous page and set pagesize (bps) Z
	      Display the previous page, consisting of i lines, (or page-size lines if no argument is given).  If i is given, the page-size is set
	      to i.

       scroll up (bs) ^B
	      Scroll up i lines (or scroll-size lines if i is not given. Initially, the scroll-size is 11).

       search backwards for pattern (bse) ?
	      Search backwards for the i-th occurrence of a regular expression which will be prompted for.  If there are less than  i  occurrences
	      of  the expression, the position in the file remains unchanged.  Otherwise, a page is displayed, starting two lines before the place
	      where the expression was found. The user's erase and kill characters may be used to edit the  expression.   Erasing  back  past  the
	      first character cancels the search command.
	      Note: Some systems do not have regex(3).	On those systems, searches are still supported, but regular expressions are not.

       skip lines backwards (bsl) S
	      Skip i lines backwards and display a page.

       skip pages backwards (bsp) F
	      Skip i pages backwards and display a page.

       scroll up and set scrollsize (bss) b
	      Scroll up i lines (or scroll-size lines if i is not given.  If i is given, the scroll-size is set to i.

       change key map (chm) ^[
	      Change from the current key map to the other (if there is one).

       exchange current page and mark (exg) x
	      Set the mark to the current page, and display the previously marked page.

       visit next file (ff) N
	      Visit the i-th next file given in the command line.

       scroll one line down or go to line (fl) ^J or ^M or j
	      If  i is not given, scroll one line down. Otherwise, i will be interpreted as a line number. A page starting with the line indicated
	      will then be displayed.

       display next page (fp) <space>
	      Display the next page, consisting of i lines, (or page-size lines if no argument is given).

       display next page and set pagesize (fps) z
	      Display the next page, consisting of i lines, (or page-size lines if no argument is given).  If i is given, the page-size is set	to
	      i.

       scroll down (fs) ^D
	      Scroll down i lines (or scroll-size lines if no argument is given).

       search forwards for pattern (fse) /
	      Search forwards for the i-th occurrence of a regular expression which will be prompted for.  If there are less than i occurrences of
	      the expression, the position in the file remains unchanged.  Otherwise, a page is displayed, starting two  lines	before	the  place
	      where  the  expression  was  found.  The user's erase and kill characters may be used to edit the expression.  Erasing back past the
	      first character cancels the search command.
	      Note: Some systems do not have regex(3).	On those systems, searches are still supported, but regular expressions are not.

       skip lines forwards (fsl) s
	      Skip i lines and display a page.

       skip pages forwards (fsp) f
	      Skip i pages and display a page.

       scroll down and set scrollsize (fss) d
	      Scroll down i lines (or scroll-size lines if i is not given.  If i is given, the scroll-size is set to i.

       help (hlp) h
	      Give a short description of all commands that are bound to a key sequence.

       set a mark (mar) m
	      Set a mark on the current page.

       repeat last search (nse) n
	      Search for the i-th occurrence of the last regular expression entered, in the direction of the last search.

       repeat last search in other direction (nsr) r
	      Search for the i-th occurrence of the last regular expression entered, but in the other direction.

       quit (qui) Q or q
	      Exit from yap.

       redraw (red) ^L
	      Redraw the current page.

       repeat (rep) .
	      Repeat the last command. This does not always make sense, so not all commands can be repeated.

       shell escape (shl) !
	      Invoke the shell with a command that will be prompted for.  In the command, the characters `%' and `!' are replaced with the current
	      file  name  and the previous shell command respectively.	The sequences `\%' and `!' are replaced by `%' and `!' respectively.  The
	      user's erase and kill characters can be used to edit the command.  Erasing back past the first character cancels the command.

       pipe to shell command (pip) |
	      Pipe the current input file into a shell command that will be prompted for.  The comments given in  the  description  of	the  shell
	      escape command apply here too.

       go to mark (tom) '
	      Display the marked page.

       top (top) ^^
	      Display a page starting with the first line of the input.

       visit file (vis) e
	      Visit a new file. The filename will be prompted for. If you just type a return, the current file is revisited.

       write input to a file (wrf) w
	      Write the input to a file, whose name will be prompted for.

       The commands take effect immediately, i.e., it is not necessary to type a carriage return.  Up to the time when the command sequence itself
       is given, the user may give an interrupt to cancel the command being formed.

AUTHOR

       Ceriel J.H. Jacobs

FILES

       /etc/termcap		Terminal capabilities data base

SEE ALSO

       termcap(5), regex(3).

BUGS

       Yap will find your terminal very stupid and act like it, if it has no way of placing the cursor on the  home  position,	or  cannot  either
       erase a line or insert one.

       In lines longer than about 2000 characters, a linefeed is silently inserted.

       The percentage, given in the prompt when yap reads from a file (and knows it), is not always very accurate.

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