.\" hexer.1	01/12/1996
.\"
.\" Copyright (c) 1995,1996 Sascha Demetrio
.\" Copyright (c) 2009 - 2011, 2014 - 2016, 2018, 2020 Peter Pentchev
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\"    If you modify any part of HEXER and redistribute it, you must add
.\"    a notice to the `README' file and the modified source files containing
.\"    information about the  changes you made.  I do not want to take
.\"    credit or be blamed for your modifications.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"    If you modify any part of HEXER and redistribute it in binary form,
.\"    you must supply a `README' file containing information about the
.\"    changes you made.
.\" 3. The name of the developer may not be used to endorse or promote
.\"    products derived from this software without specific prior written
.\"    permission.
.\"
.\" HEXER WAS DEVELOPED BY SASCHA DEMETRIO.
.\" THIS SOFTWARE SHOULD NOT BE CONSIDERED TO BE A COMMERCIAL PRODUCT.
.\" THE DEVELOPER URGES THAT USERS WHO REQUIRE A COMMERCIAL PRODUCT
.\" NOT MAKE USE OF THIS WORK.
.\"
.\" DISCLAIMER:
.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPER ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE DEVELOPER BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\" 
.TH HEXER 1 "April 24, 2020" "Hexer 1.0.6"
.\"
.\" --- Section -- NAME -------------------------------------------------------
.\"
.SH NAME
hexer \- binary file editor
.\"
.\" --- Section -- SYNOPSIS ---------------------------------------------------
.\"
.SH SYNOPSIS
.B hexer
[options] [file [...]]
.\"
.\" --- Section -- DESCRIPTION ------------------------------------------------
.\"
.SH DESCRIPTION
.B hexer
is a multi-buffer editor for viewing and manipulating binary files.  It can't
(shouldn't) be used for editing block devices, because it tries to load the
whole file into a buffer (it should work for diskettes).  The most important
features of
.B hexer
are:  multi buffers, multi level undo, command line editing with completion,
binary regular expressions (see below).
The user interface is kept similar to
.BR vi ,
so if you know how to use
.BR vi ,
you'll get started easily.
.\"
.\" --- Section -- OPTIONS ----------------------------------------------------
.\"
.SH OPTIONS
.TP 4
.BI \-R,\ \-\-readonly
.TP
.BI \-v,\ \-\-view
Edit files in read only mode.
.TP
.BI \-r,\ \-\-recover " filename"
Recover the file
.I filename
after a crash. (not implemented)
.TP
.BI \-c,\ \-\-command " command"
Start the editing session by executing the editor command
.IR command .
If
.I command
contains spaces, it must be surrounded by double quotes.  It is possible to
specify multiple commands on the command line:
.br
.BI "hexer \-c " command1 " \-c " command2 " ..."
.TP
.B \-t,\ \-\-tite
Turn off the usage of the termcap/terminfo ti/te sequence.
.TP
.B \-h,\ \-\-help
Display a short help message and exit.
.TP
.B \-V,\ \-\-version
Display program version information and exit.
.TP
.B \-F,\ \-\-features
List the features supported by the program and exit.
.TP
.BI + command
This is equivalent to the
.B \-c
option.
.LP
.B Note:
The long options are not available on all systems.
.\"
.\" --- Section -- CUSTOMIZING ------------------------------------------------
.\"
.SH CUSTOMIZING
The editor reads its startup commands from the file
.B ~/.hexerrc
(another startup file may be specified by setting the environment variable
.BR HEXERRC ).
Empty lines and lines starting with a `"'\(hycharacter (double quote) are ignored.
It is not possible to have a command and a comment in the same line.
.\"
.\" --- Section -- EDITOR COMMANDS --------------------------------------------
.\"
.SH EDITOR COMMANDS
As in
.BR vi ,
there are several editing modes:
.\"
.\" --- Subsection -- Command Mode --------------------------------------------
.\"
.TP 4
.B Command Mode
Some commands in
.B Command Mode
can take a numeric argument.  To enter a numeric argument just type the
(decimal) number.  The number will be echoed at the bottom line of the screen
as you type.  To enter an octal number, type a `0' as the first digit.
To enter a hexadecimal number, type `0x' (this is not a problem, because the
.BR x -command
with a zero counter wouldn't make sense anyway).
Some of the commands can take a visually selected area as an argument
(see subsection
.BR "Visual Mode" ).
.RS
.TP
.B b
Move backwards to the beginning of a word.
.TP
.B e
Move to the end of a word.
.TP
.B G
If a numeric argument
.B n
is given, move the cursor to position
.BR n .
If no argument is specified, set the position to the end of the buffer.
The first byte in the buffer is at position `0', so the command to move
to the beginning of the buffer is `0G'.
.TP
.B Control-G
Display the buffer name, size, status and the current position at the
bottom line.
.TP
.B h j k l
Move the cursor.  The arrow keys work as well.  The numeric argument (if
specified) determines the number rows or columns the cursor will move.
Different from
.BR vi :
the cursor can be positioned
.B behind
the last byte in the buffer.
.TP
.B i
Enter
.B Insert Mode
(see below) at the current position of the point.  If a numeric argument
.B n
is given, the typed text will be inserted
.B n
times.
.B Note:
Moving the cursor (using the arrow keys) will discard the numeric argument.
.TP
.B n
Move to the next match using the current RE.  This is equivalent to typing
`/', <Return>.
.TP
.B N
Move to the previous match using the current RE.  This is equivalent to
typing `?', <Return>.
.TP
.B Control-O
Paste over.  Copy the kill buffer to the current position overwriting the
contents of the current buffer.  If a numeric argument
.B n
is given, the kill buffer is pasted
.B n
times.
.TP
.B p
Paste.  Insert the kill buffer at the current position.  If a numeric argument
.B n
is given, the kill buffer is pasted
.B n
times.
.TP
.B r
Replace a single byte using the
.BR "Replace Mode" .
If an area is selected, all bytes in the selected area are replaced.
If a numeric argument is given, the specified number of bytes is replaced.
.TP
.B R
Enter
.B Replace Mode
(see below).  If a numeric argument
.B n
is given, the replace command is repeated
.B n
times.
.B Note:
Moving the cursor (using the arrow keys) will discard the numeric argument.
.TP
.B Control-R
Redo the last undo.
.TP
.B u
Undo the last change to the current buffer.
.LP
Whenever possible
.B hexer
creates a file
.IB name .hexer
in the current directory (the
.BR swapfile )
for each buffer visited (where
.I name
is the name of the buffer).  All changes made to the buffer
.I name
are stored in that file, so it is possible to undo (and redo) all
changes made to the buffer.  If the
.B swapfile
can't be created, the undo list is stored in the memory.
.TP
.B v
Enter
.B Visual Mode
(see below).  Visual selection of areas.
.TP
.B w
Move forward to the beginning of a word.
.TP
.B x
Delete the byte under the cursor.  If a numeric argument
.B n
is given,
.B n
bytes are deleted.
In
.BR "Visual Mode" ,
the selected area is deleted.
.B Note:
The bytes deleted using the
.BR x -command
are not copied to the kill buffer.
.TP
.B Control-X
The same as the
.BR x -command,
but the bytes deleted are copied to the kill buffer.
.TP
.B y
Yank.  Yank the byte under the cursor into the kill buffer.  If a numeric
argument
.B n
is given,
.B n
bytes are yanked into the kill buffer.
In
.BR "Visual Mode" ,
the selected area is copied to the kill buffer.
.TP
.B zb
Place the cursor in the bottom line of the screen.
.TP
.B zt
Place the cursor in the top line of the screen.
.TP
.B zz
Place the cursor in the middle line of the screen.
.br
Note that the commands
.BR zb , " zt"
and
.B zz
don't change the position in the file - only the screen is scrolled
(if necessary).
.TP
.B :
Enter
.B Exh Mode
(see below).  The
.B Exh Mode
is similar to the
.BR ex -mode
in
.BR vi ,
but not compatible.  If an area is selected, the bounds of the
selection are copied to the command line.
.TP
.B /
Search forward through the buffer using a
.BR RE ( "regular expression" ).
If no
.B RE
is specified, the
.B RE
given in the previous
.BR / -
or
.BR ? -command
is reused.
.br
.B Note:
The
.BR RE s
in
.B hexer
are a little bit different from regular expressions in 
.B vi
(see section
.BR "REGULAR EXPRESSIONS" ).
.TP
.B ?
Search reverse using a regular expression.
.TP
.B .
Repeat the last change to the buffer
.BR "at the current position" .
This means that if the previous command deleted
.B n
bytes and replaced them by
.B m
other bytes
.RB ( n
or
.B m
may be zero), the
.BR . -command
will do
.B exactly
the same at the current position in the file.
.TP
.B <
Shift the hex column left
.B n
bytes, where
.B n
is the (optional) numeric argument.  Note that the
.BR < -command
only changes the way the buffer is displayed in the hex column, the buffer
itself is kept unchanged.
.TP
.B >
Shift the hex column right
.B n
bytes.
.TP
.B Control-^
Switch to the alternate buffer (see below).
.TP
.B %
Enter a calculator command (see section
.BR CALCULATOR ).
.LP
.RE
.\"
.\" --- Subsection -- Visual Mode ---------------------------------------------
.\"
.TP
.B Visual Mode
Select an area on the buffer.  You can enter the
.B Visual Mode
by using the
.BR v -command
or by specifying an area in
.BR "Exh Mode" .
The selection starts at the cursor position when entering the
.B Visual Mode
and ends at the current cursor position.  You can leave the
.B Visual Mode
without performing a command on the selected area by pressing
.B v
or
.BR Escape .
To perform a command on the selected area simply enter the command as if
you where in
.BR "Command Mode" .
Commands that can't use the selection will ignore it.
As in
.BR "Command Mode" ,
it is possible to specify a numeric argument.  Commands that can take the
selection as an argument will ignore the numeric argument.
.\"
.\" --- Subsection -- Insert Mode ---------------------------------------------
.\"
.TP
.B Insert Mode
In
.B Insert Mode
the bytes you type are inserted at the current position of the cursor.
At any time, you can toggle the active column (hex column or text column)
by pressing the
.BR TAB
key.
If the hex column is active the bytes are entered as two digit hex numbers,
if the text column is active, the bytes are entered as ASCII text.
The
.BR Delete
or
.BR BackSpace
key deletes the previously inserted byte.  If the hex column is active, the
previously inserted nibble (hex digit) is deleted.  It is not possible
to delete more bytes than have been inserted in the current insert command.
While in
.BR "Insert Mode" ,
you can move the cursor using the arrow keys.  Note that moving the cursor
discards the numeric argument given to the insert command.
To leave the
.BR "Insert Mode" ,
type
.BR Escape .
If a numeric argument
.B n
was given to the insert command and is hasn't been discarded by a cursor
movement, the typed bytes are inserted
.B n
times.
.\"
.\" --- Subsection -- Replace Mode --------------------------------------------
.\"
.TP
.B Replace Mode
In
.B Replace Mode
you replace the bytes under the cursor as you type.  Hitting
.B BackSpace
restores the original contents of the buffer.  The effect of a numeric
argument is similar to the
.BR "Insert Mode" :
the typed bytes are replaced
.B n
times.  As in
.BR "Insert Mode" ,
moving the cursor using the arrow keys discards the numeric argument.
.\"
.\" --- Subsection -- Exh Mode ------------------------------------------------
.TP
.B Exh Mode
The
.B Exh Mode
in
.B hexer
is kept similar to the
.BR ex -mode
in
.BR vi .
Typically, an
.B exh
command looks like:
.RS
.TP
.BI : "area command arguments"
Perform the command
.I command
on the area
.IR area .
.TP
.TP
.BI : "command arguments"
Perform the command
.B command
at the current position.
.TP
.BI : area
Select the area
.IR area .
.TP
.BI : position
Move the cursor to position
.IR position .
.LP
An area may be defined as:
.TP
.I position1,position2
The area starts at
.I position1
and ends at
.I position2
(inclusive).
.TP
.I position
The area selects one byte at
.I position
.TP
.I %
The area selects the entire buffer.
.LP
A position may be defined as:
.TP
.I offset
A decimal, octal (prefixed with `0') or hex (prefixed with `0x') number.
.TP
.I .
The beginning of the buffer.
.TP
.I $
The end of the buffer.
.TP
.RI / regexp /
A regular expression
(see section
.BR "REGULAR EXPRESSIONS" ).
The buffer is searched forward starting at the current
position.  If a match was found, the current position is set to the position
of the match.
.TP
.RI ? regexp ?
The buffer is searched reverse.
.LP
Commands may be abbreviated with a unique prefix of the command, some commands
may be abbreviated with a single character, even if that character isn't a
unique prefix of the command name.
Currently the following commands are supported:
.TP
.B s, substitute
.B Synopsis:
.I area
.B s
.RI / regexp / replace / flags
.br
Search for the regular expression
.I regexp
and replace it with
.I replace
(see section
.BR "REGULAR EXPRESSIONS" ).
.I replace
may contain `\\' references to subexpressions of 
.RI regexp .
.IR flags :
.RS
.TP
.BR g :
global, this flag is ignored (it doesn't make sense in a binary editor).
.TP
.BR c :
confirm, ask the user to confirm each substitution.
.LP
(Note that the `/' character used as separator could be any character,
it's just common practice to use `/'.) Trailing separators may be omitted.
If
.I area
is omitted, the whole buffer is searched.
.RE
.TP
.B w, write
.B Synopsis:
.I area
.B w
.I filename
.br
Write
.I area
to the file
.IR filename .
If
.I area
is omitted. the whole buffer is written to the file, if
.I filename
is omitted, the filename associated with the buffer is used.
.TP
.B r, read
.B Synopsis:
.I position
.B r
.I filename
.br
Insert the contents of the file
.I filename
at
.IR position .
If
.I position
is omitted, the current position is used.
.TP
.B e, edit
.B Synopsis: e
.I name
.B or: e #
.br
Change to buffer
.IR name .
If there is no such buffer,
.B hexer
tries to open a file named
.I name
and load it into a new buffer.  If
.I name
is a hash sign
.RB ( # ),
the alternate buffer is selected.  On success the current
buffer becomes the alternate buffer.
.TP
.B b, buffer
.B Synopsis: b
.I name
.br
.B or: b
.br
Change to buffer
.IR name .
On success the current buffer becomes the alternate buffer.  If
.I name
is omitted, a list of all buffers is displayed.
.TP
.B n, next
Select the next buffer in the buffer list.
.TP
.B N, previous
Select the previous buffer in th buffer list.
.TP
.B S, skip
Select the next unvisited buffer in the buffer list.
.TP
.B rewind
Select the first buffer in the buffer list.
.TP
.B wall
Write all unsaved buffers.
.TP
.B c, close
.B Synopsis: c
.I name
.br
.B or: c!
.I name
.br
.B or: c
.br
.B or: c!
.br
Close the buffer
.IR name .
If
.I name
is omitted, the current buffer is closed.  If the buffer has been modified,
but not saved, it can't be closed using a
.BR :c -command;
use
.B :c!
to override.
.TP
.B h, help
View an online help text.
.TP
.B q, quit
.B Synopsis: q
.I name
.br
.B or: q!
.I name
.br
.B or: q
.br
.B or: q!
.br
Close all buffers and exit the editor.  If an opened buffer has bee modified,
but not saved, the
.BR :q -command
can't be performed; use
.B :q!
to override.
.TP
.B map
.TP
.B imap
.TP
.B vmap
.B Synopsis: map
.I from
.I to
.br
.B or: imap
.I from
.I to
.br
.B or: vmap
.I from
.I to
.br
The key sequence
.I from
is mapped to
.IR to .
To enter special keys (e.g. function keys), mask them using
.BR "Control-V" .
.B :map
affects the
.B Command Mode
only,
.B :imap
affects the
.B Insert Mode
only and
.B :vmap
affects the
.B Visual Mode
only.  It is not possible to re-map key sequences on the command line editor.
.TP
.B unmap
.TP
.B iunmap
.TP
.B vunmap
.B Synopsis: unmap
.I from
.br
.B or: iunmap
.I from
.br
.B or: vunmap
.I from
.br
Delete a key mapping created with
.BR :map , " :imap"
or
.BR :vmap .
.TP
.B set
.B Synopsis: set
.I variable
[...]
.br
.B or: set
.IR variable = value
[...]
.br
.BI "or: set no" variable
[...]
.br
.B or: set
.br
There are not too many variables that could be modified, this might change
though.  The following variables can be used:
.B iso
(bool):  display the whole ISO-8859/1 character set;
.B ascii
(bool):  display ASCII characters only;
.B TERM
(string):  the name of the terminal;
.B maxmatch
(number),
.B specialnl
(bool): see section
.BR "REGULAR EXPRESSIONS" .
.B :set
called without an argument lists all variables and values.
.TP
.B d, delete
.B Synopsis:
.I area
.B d
.br
Delete all bytes in
.IR area .
The deleted bytes are copied to the kill buffer.
.TP
.B y, yank
.B Synopsis:
.I area
.B y
.br
Copy the bytes in
.I area
to the kill buffer.
.TP
.B version
Display the version number of
.BR hexer .
.TP
.B zz
Place the cursor in the middle line of the screen.  Note that the
screen is scrolled (if necessary); the cursor position is kept unchanged.
.TP
.B zt
Place the cursor in the top line of the screen.
.TP
.B zb
Place the cursor in the bottom line of the screen.
.TP
.B wq
The same as
.BR :x .
.TP
.B x, exit
Save all buffers and exit the editor.
.LP
If a command is called and can't use the given positions, areas or arguments,
the additional positions, areas, arguments are ignored.
.br
.B Conditional commands:
It is possible to specify a list of terminal names for which the given
command should be executed. The syntax is:
.RS
.BI : terminals : command
.RE
where
.I terminals
is a colon-separated list of terminal names.  The command is executed if and
only if the value of
.B TERM
is in the list.  I.e. you could have a command like
.RS
.B :xterm:set iso
.RE
in your
.BR .hexerrc -file
(use the ISO character set only if working on an xterm).
.RE
.\"
.\" --- Subsection -- Cursor Motion -------------------------------------------
.\"
.TP
.B Cursor Motion
In
.BR "Command Mode" , " Insert Mode" , " Replace Mode"
.RB and " Visual Mode" ,
you can use the following cursor motion commands:
.RS
.TP
.B Arrow Keys
Move the cursor.
.TP
.B Control-F
Move forward one page.
.TP
.B Control-B
Move back one page.
.TP
.B Control-D
Move forward half a page.
.TP
.B Control-U
Move back half a page.
.LP
.RE
.\"
.\" --- Section -- COMMAND LINE EDITING ---------------------------------------
.\"
.SH COMMAND LINE EDITING
On the command line you can use the following commands:
.TP
.B UpArrow DownArrow
Move up and down through the history of the current context.
.TP
.B LeftArrow RightArrow
Move the cursor.
.TP
.B Control-A
Move the cursor to the beginning of the line.
.TP
.B Control-E
Move the cursor to the end of the line.
.TP
.B Control-K
Delete all characters from the current cursor position up to the end of the
line.
.TP
.B Control-U
Delete all characters from the beginning of the line up to the current
cursor position.
.TP
.B Delete
.TP
.B BackSpace
Delete the character left of the cursor.
.TP
.B Control-D
Delete the character under the cursor.
.TP
.B Enter Return
Accept the line.
.TP
.B Escape
Discard the line.
.B Note:
This is different from
.BR vi .
.TP
.B TAB
Try to complete currently typed word.  If the completion is not unique,
the word is completed as far as unique.  If the
.BR TAB
key is hit twice on the same position,  a list of all possible completions is
displayed.
.\"
.\" --- Section -- REGULAR EXPRESSIONS ----------------------------------------
.\"
.SH REGULAR EXPRESSIONS
In this section it is assumed that you are familiar with REs (regular
expressions).
In most applications
.RB ( egrep ", " vi ", ...)"
REs work on lines, that means it is not possible to use a RE containing
a line break (newline character).
In
.BR hexer ,
the buffer is not split up into distinct lines and a newline character
is considered to be a `normal' character, now here's the problem:
imagine searching for "a.*b" in a 5 MB file, this would take very long
(might be up to several minutes on a slow machine).  That's why there's
a
.B maxmatch
limit (a repeat operator matches at most
.B maxmatch
occurrences of its operand).  The default value of
.B maxmatch
is 1024, but it may be customized using the
.BR :set -command.
For simple expressions (expressions for which the length of the match can
be determined from the expression) it is possible to override the
.B maxmatch
limit by doubling the `*' or `+' operator, e.g. "a.**b" or
"foo\\(bar\\)\\+\\+".
.br
Note that the context specifiers `^'/`$' (beginning/end of a line) and
`\\<'/`\\>' (beginning/end of a word) are available and actually do
what you expect.  If you don't want the atoms `.' and `[^...]' to match
the newline character you can set the
.B specialnl
option using the
.BR :set -command.
.br
To enter a special character, you can use the standard C `\\'\(hyescape
sequences.  To enter a character using its octal code, use a `\\o'\(hyprefix
followed by up to three octal digits.
(C-style octal escapes are not supported, because `\\0', ... `\\9' are
interpreted as back-references to subexpressions of the RE.)
To enter a character using it's hex code, type a `\\x'-prefix followed
by up to two hex digits; decimal codes can be entered using a `\\d'\(hyprefix
followed by up to three decimal digits.  It is possible to enter strings
of codes by doubling the base specifier, e.g. "\\xxfe ff 5a 7e" or
"\\oo276 277 132 176".  Note that such a string is treated as an atom, i.e.
the RE "\\xxff fe*" matches any number (<
.BR maxmatch )
of repetitions of
.BR "ff fe" .
.br
It is possible to use all kinds of character `\\'\(hyescapes (escapes
representing a single character) within `[]'\(hyranges.  Within a range,
the `o' selecting an octal base for the escape may be omitted, since
back-references within a range don't make sense.  When specifying a
minimum and/or maximum number of repetitions using the `\\{,}'\(hyoperator,
the numbers may be given in decimal (no prefix), octal (`0'-prefix) or
hex (`0x'-prefix).  If no maximum number is specified and the operand is
not a simple expression, at most
.B maxmatch
matches will be found.
.\"
.\" --- Section -- CALCULATOR -------------------------------------------------
.\"
.SH CALCULATOR
.B Hexer
provides a simple calculator
.RB ( myc )
capable of all operations available in C.
To enter a
.B myc
command just enter a
.B %
(percent) sign and an expression in infix notation.
It is possible to use parentheses.
.B myc
understands the following binary infix operators (from highest priority to
lowest):
.B **
(power),
.B *
(multiply),
.B /
(divide),
.B %
(modulo),
.B +
(add),
.B -
(subtract),
.B <<
(shift left),
.B >>
(shift right),
.B <
(less),
.B <=
(less or equal),
.B >
(greater),
.B >=
(greater or equal),
.B ==
(equal),
.B !=
(not equal),
.B &
(arithmetical and),
.B |
(arithmetical or),
.B ^
(arithmetical exclusive or),
.B &&
(logical and),
.B ||
(logical or),
.B =
(assign);  and the following unary prefix operators:
.B -
(negate, unary minus),
.B !
(logical not),
.B ~
(bitwise complement).
.B myc
knows three data types:
.BR boolean ,
.B integer
(32 bit),
.B float
(64 bit, equivalent to C double).
On some esoteric platforms the precision of integer and float may be
different.
As in C the result of a division depends on the data types of the operands.
An integer divided by an integer yields an integer.
If you want the result to be a float, make sure one of the operands is a
float, e.g. type
.I 4/7.
instead of
.I 4/7
or
.I a/(b+0.)
instead of
.IR a/b .
The power operation returns a float if the result is too large to fit in an
integer.
The result of a calculation is stored in the special variables
.B $$
and
.BI $ n
where
.I n
is the number of the command.
.\"
.\" --- Section -- BUGS -------------------------------------------------------
.\"
.SH BUGS
Probably.  Please report bugs to
.IR demetrio@cs.uni-sb.de .
.\"
.\" --- Section -- COPYRIGHT --------------------------------------------------
.\"
.SH COPYRIGHT
.B hexer
is
.BR "not in the public domain" ,
but freely distributable.  It may be used for any non-commercial purpose.
See file
.B COPYRIGHT
for details.
.\"
.\" --- Section -- AUTHOR -----------------------------------------------------
.\"
.SH AUTHOR
Sascha Demetrio
.br
.I demetrio@cs.uni-sb.de