svn commit: r202719 - in head: . gnu/usr.bin usr.bin usr.bin/bc
usr.bin/bc/USD.doc usr.bin/dc usr.bin/dc/USD.doc
Gabor Kovesdan
gabor at FreeBSD.org
Wed Jan 20 21:30:53 UTC 2010
Author: gabor (doc,ports committer)
Date: Wed Jan 20 21:30:52 2010
New Revision: 202719
URL: http://svn.freebsd.org/changeset/base/202719
Log:
Replace GNU bc/dc with BSDL versions ported from OpenBSD. They have a good
compatibility level with the GNU counterparts and have shown to be mature
enough. For now, the GNU versions aren't removed from the tree, just detached
from the build.
Sponsored by: Google Summer of Code 2008
Portbuild run by: erwin
Approved by: delphij
Added:
head/usr.bin/bc/
head/usr.bin/bc/Makefile (contents, props changed)
head/usr.bin/bc/USD.doc/
head/usr.bin/bc/USD.doc/Makefile (contents, props changed)
head/usr.bin/bc/USD.doc/bc (contents, props changed)
head/usr.bin/bc/bc.1 (contents, props changed)
head/usr.bin/bc/bc.library (contents, props changed)
head/usr.bin/bc/bc.y (contents, props changed)
head/usr.bin/bc/extern.h (contents, props changed)
head/usr.bin/bc/pathnames.h (contents, props changed)
head/usr.bin/bc/scan.l (contents, props changed)
head/usr.bin/dc/
head/usr.bin/dc/Makefile (contents, props changed)
head/usr.bin/dc/USD.doc/
head/usr.bin/dc/USD.doc/Makefile (contents, props changed)
head/usr.bin/dc/USD.doc/dc (contents, props changed)
head/usr.bin/dc/bcode.c (contents, props changed)
head/usr.bin/dc/bcode.h (contents, props changed)
head/usr.bin/dc/dc.1 (contents, props changed)
head/usr.bin/dc/dc.c (contents, props changed)
head/usr.bin/dc/extern.h (contents, props changed)
head/usr.bin/dc/inout.c (contents, props changed)
head/usr.bin/dc/mem.c (contents, props changed)
head/usr.bin/dc/stack.c (contents, props changed)
Modified:
head/ObsoleteFiles.inc
head/gnu/usr.bin/Makefile
head/usr.bin/Makefile
Modified: head/ObsoleteFiles.inc
==============================================================================
--- head/ObsoleteFiles.inc Wed Jan 20 21:12:30 2010 (r202718)
+++ head/ObsoleteFiles.inc Wed Jan 20 21:30:52 2010 (r202719)
@@ -14,6 +14,13 @@
# The file is partitioned: OLD_FILES first, then OLD_LIBS and OLD_DIRS last.
#
+# 20100120: replacing GNU bc/dc with BSDL versions
+OLD_FILES+=usr/share/examples/bc/ckbook.b
+OLD_FILES+=usr/share/examples/bc/pi.b
+OLD_FILES+=usr/share/examples/bc/primes.b
+OLD_FILES+=usr/share/examples/bc/twins.b
+OLD_FILES+=usr/share/info/dc.info.gz
+OLD_DIRS+=usr/share/examples/bc
# 20100114: removal of ttyslot(3)
OLD_FILES+=usr/share/man/man3/ttyslot.3.gz
# 20100113: remove utmp.h, replace it by utmpx.h
Modified: head/gnu/usr.bin/Makefile
==============================================================================
--- head/gnu/usr.bin/Makefile Wed Jan 20 21:12:30 2010 (r202718)
+++ head/gnu/usr.bin/Makefile Wed Jan 20 21:30:52 2010 (r202719)
@@ -2,12 +2,10 @@
.include <bsd.own.mk>
-SUBDIR= bc \
- ${_binutils} \
+SUBDIR= ${_binutils} \
${_cc} \
${_cpio} \
${_cvs} \
- dc \
dialog \
diff \
diff3 \
Modified: head/usr.bin/Makefile
==============================================================================
--- head/usr.bin/Makefile Wed Jan 20 21:12:30 2010 (r202718)
+++ head/usr.bin/Makefile Wed Jan 20 21:30:52 2010 (r202719)
@@ -18,6 +18,7 @@ SUBDIR= alias \
awk \
banner \
basename \
+ bc \
${_biff} \
${_bluetooth} \
brandelf \
@@ -49,6 +50,7 @@ SUBDIR= alias \
${_csup} \
${_ctags} \
cut \
+ dc \
${_dig} \
dirname \
du \
Added: head/usr.bin/bc/Makefile
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ head/usr.bin/bc/Makefile Wed Jan 20 21:30:52 2010 (r202719)
@@ -0,0 +1,17 @@
+# $FreeBSD$
+# $OpenBSD: Makefile,v 1.4 2006/06/30 19:02:28 otto Exp $
+
+PROG= bc
+SRCS= bc.y scan.l
+CFLAGS+= -I. -I${.CURDIR}
+WARNS?= 6
+#SUBDIR+= USD.doc
+
+FILES+= bc.library
+FILESDIR= ${SHAREDIR}/misc
+
+#beforeinstall:
+# install -c -o ${BINOWN} -g ${BINGRP} -m 444 ${.CURDIR}/bc.library \
+# ${DESTDIR}/usr/share/misc
+
+.include <bsd.prog.mk>
Added: head/usr.bin/bc/USD.doc/Makefile
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ head/usr.bin/bc/USD.doc/Makefile Wed Jan 20 21:30:52 2010 (r202719)
@@ -0,0 +1,13 @@
+# $FreeBSD$
+# $OpenBSD: Makefile,v 1.3 2004/02/01 15:18:01 jmc Exp $
+
+DOC= bc
+DIR= usd/06.bc
+SRCS= bc
+MACROS= -ms
+BINDIR= /usr/share/doc/papers
+
+paper.txt: ${SRCS}
+ ${ROFF} -Tascii ${SRCS} > ${.TARGET}
+
+.include <bsd.doc.mk>
Added: head/usr.bin/bc/USD.doc/bc
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ head/usr.bin/bc/USD.doc/bc Wed Jan 20 21:30:52 2010 (r202719)
@@ -0,0 +1,1241 @@
+.\" $FreeBSD$
+.\" $OpenBSD: bc,v 1.9 2004/07/09 10:23:05 jmc Exp $
+.\"
+.\" Copyright (C) Caldera International Inc. 2001-2002.
+.\" 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 and documentation must retain the above
+.\" copyright notice, this list of conditions and the following disclaimer.
+.\" 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.
+.\" 3. All advertising materials mentioning features or use of this software
+.\" must display the following acknowledgement:
+.\" This product includes software developed or owned by Caldera
+.\" International, Inc.
+.\" 4. Neither the name of Caldera International, Inc. nor the names of other
+.\" contributors may be used to endorse or promote products derived from
+.\" this software without specific prior written permission.
+.\"
+.\" USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA
+.\" INTERNATIONAL, INC. AND CONTRIBUTORS ``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 CALDERA INTERNATIONAL, INC. 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.
+.\"
+.\" @(#)bc 6.2 (Berkeley) 4/17/91
+.\"
+.if n \{\
+.po 5n
+.ll 70n
+.\}
+.EH 'USD:6-%''BC \- An Arbitrary Precision Desk-Calculator Language'
+.OH 'BC \- An Arbitrary Precision Desk-Calculator Language''USD:6-%'
+.\".RP
+.TL
+BC \- An Arbitrary Precision Desk-Calculator Language
+.AU
+Lorinda Cherry
+.AU
+Robert Morris
+.AI
+.\" .MH
+.AB
+BC is a language and a compiler for doing arbitrary precision arithmetic
+on the PDP-11 under the
+.UX
+time-sharing
+system. The output of the compiler is interpreted and executed by
+a collection of routines which can input, output, and do
+arithmetic on indefinitely large integers and on scaled fixed-point
+numbers.
+.PP
+These routines are themselves based on a dynamic storage allocator.
+Overflow does not occur until all available core storage
+is exhausted.
+.PP
+The language has a complete control structure as well as immediate-mode
+operation. Functions can be defined and saved for later execution.
+.PP
+Two five hundred-digit numbers can be multiplied to give a
+thousand digit result in about ten seconds.
+.PP
+A small collection of library functions is also available,
+including sin, cos, arctan, log, exponential, and Bessel functions of
+integer order.
+.PP
+Some of the uses of this compiler are
+.IP \-
+to do computation with large integers,
+.IP \-
+to do computation accurate to many decimal places,
+.IP \-
+conversion of numbers from one base to another base.
+.AE
+.PP
+.SH
+Introduction
+.PP
+BC is a language and a compiler for doing arbitrary precision
+arithmetic on the
+.UX
+time-sharing system [1].
+The compiler was written to make conveniently available a
+collection of routines (called DC [5]) which are capable of doing
+arithmetic on integers of arbitrary size. The compiler
+is by no means intended to provide a complete programming
+language.
+It is a minimal language facility.
+.PP
+There is a scaling provision that permits the
+use of decimal point notation.
+Provision is made for input and output in bases other than
+decimal. Numbers can be converted from decimal to octal by
+simply setting the output base to equal 8.
+.PP
+The actual limit on the number of digits that can
+be handled depends on the amount of storage available on the machine.
+Manipulation of numbers with many hundreds of digits
+is possible even on the smallest versions of
+.UX .
+.PP
+The syntax of BC has been deliberately selected to agree
+substantially with the C language [2]. Those who
+are familiar with C will find few surprises in this language.
+.SH
+Simple Computations with Integers
+.PP
+The simplest kind of statement is an arithmetic expression
+on a line by itself.
+For instance, if you type in the line:
+.DS
+.ft B
+142857 + 285714
+.ft P
+.DE
+the program responds immediately with the line
+.DS
+.ft B
+428571
+.ft P
+.DE
+The operators \-, *, /, %, and ^ can also be used; they
+indicate subtraction, multiplication, division, remaindering, and
+exponentiation, respectively. Division of integers produces an
+integer result truncated toward zero.
+Division by zero produces an error
+comment.
+.PP
+Any term in an expression may be prefixed by a minus sign to
+indicate that it is to be negated (the `unary' minus sign).
+The expression
+.DS
+.ft B
+7+\-3
+.ft P
+.DE
+is interpreted to mean that \-3 is to be added to 7.
+.PP
+More complex expressions with several operators and with
+parentheses are interpreted just as in
+Fortran, with ^ having the greatest binding
+power, then * and % and /, and finally + and \-.
+Contents of parentheses are evaluated before material
+outside the parentheses.
+Exponentiations are
+performed from right to left and the other operators
+from left to right.
+The two expressions
+.DS
+.ft B
+a^b^c and a^(b^c)
+.ft P
+.DE
+are equivalent, as are the two expressions
+.DS
+.ft B
+a*b*c and (a*b)*c
+.ft P
+.DE
+BC shares with Fortran and C the undesirable convention that
+.DS
+\fBa/b*c\fP is equivalent to \fB(a/b)*c\fP
+.ft P
+.DE
+.PP
+Internal storage registers to hold numbers have single lower-case
+letter names. The value of an expression can be assigned to
+a register in the usual way. The statement
+.DS
+.ft B
+x = x + 3
+.ft P
+.DE
+has the effect of increasing by three the value of the contents of the
+register named x.
+When, as in this case, the outermost operator is an =, the
+assignment is performed but the result is not printed.
+Only 26 of these named storage registers are available.
+.PP
+There is a built-in square root function whose
+result is truncated to an integer (but see scaling below).
+The lines
+.DS
+.ft B
+x = sqrt(191)
+x
+.ft P
+.DE
+produce the printed result
+.DS
+.ft B
+13
+.ft P
+.DE
+.SH
+Bases
+.PP
+There are special internal quantities, called `ibase' and `obase'.
+The contents of `ibase', initially set to 10,
+determines the base used for interpreting numbers read in.
+For example, the lines
+.DS
+.ft B
+ibase = 8
+11
+.ft P
+.DE
+will produce the output line
+.DS
+.ft B
+9
+.ft P
+.DE
+and you are all set up to do octal to decimal conversions.
+Beware, however of trying to change the input base back
+to decimal by typing
+.DS
+.ft B
+ibase = 10
+.ft P
+.DE
+Because the number 10 is interpreted as octal, this statement will
+have no effect.
+For those who deal in hexadecimal notation,
+the characters A\-F are permitted in numbers
+(no matter what base is in effect)
+and are
+interpreted as digits having values 10\-15 respectively.
+The statement
+.DS
+.ft B
+ibase = A
+.ft P
+.DE
+will change you back to decimal input base no matter what the
+current input base is.
+Negative and large positive input bases are
+permitted but useless.
+No mechanism has been provided for the input of arbitrary
+numbers in bases less than 1 and greater than 16.
+.PP
+The contents of `obase', initially set to 10, are used as the base for output
+numbers. The lines
+.DS
+.ft B
+obase = 16
+1000
+.ft P
+.DE
+will produce the output line
+.DS
+.ft B
+3E8
+.ft P
+.DE
+which is to be interpreted as a 3-digit hexadecimal number.
+Very large output bases are permitted, and they are sometimes useful.
+For example, large numbers can be output in groups of five digits
+by setting `obase' to 100000.
+Strange (i.e. 1, 0, or negative) output bases are
+handled appropriately.
+.PP
+Very large numbers are split across lines with 70 characters per line.
+Lines which are continued end with \\.
+Decimal output conversion is practically instantaneous, but output
+of very large numbers (i.e., more than 100 digits) with other bases
+is rather slow.
+Non-decimal output conversion of
+a one hundred digit number takes about
+three seconds.
+.PP
+It is best to remember that `ibase' and `obase' have no effect
+whatever on the course of internal computation or
+on the evaluation of expressions, but only affect input and
+output conversion, respectively.
+.SH
+Scaling
+.PP
+A third special internal quantity called `scale' is
+used to determine the scale of calculated
+quantities.
+Numbers may have
+up to a specific number of decimal digits after the decimal point.
+This fractional part is retained in further computations.
+We refer to the number of digits after the decimal point of
+a number as its scale.
+The current implementation allows scales to be as large as can be
+represented by a 32-bit unsigned number minus one.
+This is a non-portable extension.
+The original implementation allowed for a maximum scale of 99.
+.PP
+When two scaled numbers are combined by
+means of one of the arithmetic operations, the result
+has a scale determined by the following rules. For
+addition and subtraction, the scale of the result is the larger
+of the scales of the two operands. In this case,
+there is never any truncation of the result.
+For multiplications, the scale of the result is never
+less than the maximum of the two scales of the operands,
+never more than the sum of the scales of the operands
+and, subject to those two restrictions,
+the scale of the result is set equal to the contents of the internal
+quantity `scale'.
+The scale of a quotient is the contents of the internal
+quantity `scale'. The scale of a remainder is
+the sum of the scales of the quotient and the divisor.
+The result of an exponentiation is scaled as if
+the implied multiplications were performed.
+An exponent must be an integer.
+The scale of a square root is set to the maximum of the scale
+of the argument and the contents of `scale'.
+.PP
+All of the internal operations are actually carried out in terms
+of integers, with digits being discarded when necessary.
+In every case where digits are discarded, truncation and
+not rounding is performed.
+.PP
+The contents of
+`scale' must be no greater than
+4294967294 and no less than 0. It is initially set to 0.
+.PP
+The internal quantities `scale', `ibase', and `obase' can be
+used in expressions just like other variables.
+The line
+.DS
+.ft B
+scale = scale + 1
+.ft P
+.DE
+increases the value of `scale' by one, and the line
+.DS
+.ft B
+scale
+.ft P
+.DE
+causes the current value of `scale' to be printed.
+.PP
+The value of `scale' retains its meaning as a
+number of decimal digits to be retained in internal
+computation even when `ibase' or `obase' are not equal to 10.
+The internal computations (which are still conducted in decimal,
+regardless of the bases) are performed to the specified number
+of decimal digits, never hexadecimal or octal or any
+other kind of digits.
+.SH
+Functions
+.PP
+The name of a function is a single lower-case letter.
+Function names are permitted to collide with simple
+variable names.
+Twenty-six different defined functions are permitted
+in addition to the twenty-six variable names.
+The line
+.DS
+.ft B
+ define a(x){
+.ft P
+.DE
+begins the definition of a function with one argument.
+This line must be followed by one or more statements,
+which make up the body of the function, ending
+with a right brace }.
+Return of control from a function occurs when a return
+statement is executed or when the end of the function is reached.
+The return statement can take either
+of the two forms
+.DS
+.ft B
+return
+return(x)
+.ft P
+.DE
+In the first case, the value of the function is 0, and in
+the second, the value of the expression in parentheses.
+.PP
+Variables used in the function can be declared as automatic
+by a statement of the form
+.DS
+.ft B
+auto x,y,z
+.ft P
+.DE
+There can be only one `auto' statement in a function and it must
+be the first statement in the definition.
+These automatic variables are allocated space and initialized
+to zero on entry to the function and thrown away on return. The
+values of any variables with the same names outside the function
+are not disturbed.
+Functions may be called recursively and the automatic variables
+at each level of call are protected.
+The parameters named in a function definition are treated in
+the same way as the automatic variables of that function
+with the single exception that they are given a value
+on entry to the function.
+An example of a function definition is
+.DS
+.ft B
+ define a(x,y){
+ auto z
+ z = x*y
+ return(z)
+ }
+.ft P
+.DE
+The value of this function, when called, will be the
+product of its
+two arguments.
+.PP
+A function is called by the appearance of its name
+followed by a string of arguments enclosed in
+parentheses and separated by commas.
+The result
+is unpredictable if the wrong number of arguments is used.
+.PP
+Functions with no arguments are defined and called using
+parentheses with nothing between them: b().
+.PP
+If the function
+.ft I
+a
+.ft
+above has been defined, then the line
+.DS
+.ft B
+a(7,3.14)
+.ft P
+.DE
+would cause the result 21.98 to be printed and the line
+.DS
+.ft B
+x = a(a(3,4),5)
+.ft P
+.DE
+would cause the value of x to become 60.
+.SH
+Subscripted Variables
+.PP
+A single lower-case letter variable name
+followed by an expression in brackets is called a subscripted
+variable (an array element).
+The variable name is called the array name and the expression
+in brackets is called the subscript.
+Only one-dimensional arrays are
+permitted. The names of arrays are permitted to
+collide with the names of simple variables and function names.
+Any fractional
+part of a subscript is discarded before use.
+Subscripts must be greater than or equal to zero and
+less than or equal to 2047.
+.PP
+Subscripted variables may be freely used in expressions, in
+function calls, and in return statements.
+.PP
+An array name may be used as an argument to a function,
+or may be declared as automatic in
+a function definition by the use of empty brackets:
+.DS
+.ft B
+f(a[\|])
+define f(a[\|])
+auto a[\|]
+.ft P
+.DE
+When an array name is so used, the whole contents of the array
+are copied for the use of the function, and thrown away on exit
+from the function.
+Array names which refer to whole arrays cannot be used
+in any other contexts.
+.SH
+Control Statements
+.PP
+The `if', the `while', and the `for' statements
+may be used to alter the flow within programs or to cause iteration.
+The range of each of them is a statement or
+a compound statement consisting of a collection of
+statements enclosed in braces.
+They are written in the following way
+.DS
+.ft B
+if(relation) statement
+if(relation) statement else statement
+while(relation) statement
+for(expression1; relation; expression2) statement
+.ft P
+.DE
+or
+.DS
+.ft B
+if(relation) {statements}
+if(relation) {statements} else {statements}
+while(relation) {statements}
+for(expression1; relation; expression2) {statements}
+.ft P
+.DE
+.PP
+A relation in one of the control statements is an expression of the form
+.DS
+.ft B
+x>y
+.ft P
+.DE
+where two expressions are related by one of the six relational
+operators `<', `>', `<=', `>=', `==', or `!='.
+The relation `=='
+stands for `equal to' and `!=' stands for `not equal to'.
+The meaning of the remaining relational operators is
+clear.
+.PP
+BEWARE of using `=' instead of `==' in a relational. Unfortunately,
+both of them are legal, so you will not get a diagnostic
+message, but `=' really will not do a comparison.
+.PP
+The `if' statement causes execution of its range
+if and only if the relation is true.
+Then control passes to the next statement in sequence.
+If an `else' branch is present, the statements in this branch are
+executed if the relation is false.
+The `else' keyword is a non-portable extension.
+.PP
+The `while' statement causes execution of its range
+repeatedly as long as the relation
+is true. The relation is tested before each execution
+of its range and if the relation
+is false, control passes to the next statement beyond the range
+of the while.
+.PP
+The `for' statement begins
+by executing `expression1'. Then the relation is tested
+and, if true, the statements in the range of the `for' are executed.
+Then `expression2' is executed. The relation is tested, and so on.
+The typical use of the `for' statement is for a controlled iteration,
+as in the statement
+.DS
+.ft B
+for(i=1; i<=10; i=i+1) i
+.ft P
+.DE
+which will print the integers from 1 to 10.
+Here are some examples of the use of the control statements.
+.DS
+.ft B
+define f(n){
+auto i, x
+x=1
+for(i=1; i<=n; i=i+1) x=x*i
+return(x)
+}
+.ft P
+.DE
+The line
+.DS
+.ft B
+ f(a)
+.ft P
+.DE
+will print
+.ft I
+a
+.ft
+factorial if
+.ft I
+a
+.ft
+is a positive integer.
+Here is the definition of a function which will
+compute values of the binomial coefficient
+(m and n are assumed to be positive integers).
+.DS
+.ft B
+define b(n,m){
+auto x, j
+x=1
+for(j=1; j<=m; j=j+1) x=x*(n\-j+1)/j
+return(x)
+}
+.ft P
+.DE
+The following function computes values of the exponential function
+by summing the appropriate series
+without regard for possible truncation errors:
+.DS
+.ft B
+scale = 20
+define e(x){
+ auto a, b, c, d, n
+ a = 1
+ b = 1
+ c = 1
+ d = 0
+ n = 1
+ while(1==1){
+ a = a*x
+ b = b*n
+ c = c + a/b
+ n = n + 1
+ if(c==d) return(c)
+ d = c
+ }
+}
+.ft P
+.DE
+.SH
+Some Details
+.PP
+There are some language features that every user should know
+about even if he will not use them.
+.PP
+Normally statements are typed one to a line. It is also permissible
+to type several statements on a line separated by semicolons.
+.PP
+If an assignment statement is parenthesized, it then has
+a value and it can be used anywhere that an expression can.
+For example, the line
+.DS
+.ft B
+(x=y+17)
+.ft P
+.DE
+not only makes the indicated assignment, but also prints the
+resulting value.
+.PP
+Here is an example of a use of the value of an
+assignment statement even when it is not parenthesized.
+.DS
+.ft B
+x = a[i=i+1]
+.ft P
+.DE
+causes a value to be assigned to x and also increments i
+before it is used as a subscript.
+.PP
+The following constructs work in BC in exactly the same manner
+as they do in the C language. Consult the appendix or the
+C manuals [2] for their exact workings.
+.DS
+.ft B
+.ta 2i
+x=y=z is the same as x=(y=z)
+x += y x = x+y
+x \-= y x = x\-y
+x *= y x = x*y
+x /= y x = x/y
+x %= y x = x%y
+x ^= y x = x^y
+x++ (x=x+1)\-1
+x\-\- (x=x\-1)+1
+++x x = x+1
+\-\-x x = x\-1
+.ft P
+.DE
+Even if you don't intend to use the constructs,
+if you type one inadvertently, something correct but unexpected
+may happen.
+.SH
+Three Important Things
+.PP
+1. To exit a BC program, type `quit'.
+.PP
+2. There is a comment convention identical to that of C and
+of PL/I. Comments begin with `/*' and end with `*/'.
+As a non-portable extension, comments may also start with a `#' and end with
+a newline.
+The newline is not part of the comment.
+.PP
+3. There is a library of math functions which may be obtained by
+typing at command level
+.DS
+.ft B
+bc \-l
+.ft P
+.DE
+This command will load a set of library functions
+which, at the time of writing, consists of sine (named `s'),
+cosine (`c'), arctangent (`a'), natural logarithm (`l'),
+exponential (`e') and Bessel functions of integer order (`j(n,x)'). Doubtless more functions will be added
+in time.
+The library sets the scale to 20. You can reset it to something
+else if you like.
+The design of these mathematical library routines
+is discussed elsewhere [3].
+.PP
+If you type
+.DS
+.ft B
+bc file ...
+.ft P
+.DE
+BC will read and execute the named file or files before accepting
+commands from the keyboard. In this way, you may load your
+favorite programs and function definitions.
+.SH
+Acknowledgement
+.PP
+The compiler is written in YACC [4]; its original
+version was written by S. C. Johnson.
+.SH
+References
+.IP [1]
+K. Thompson and D. M. Ritchie,
+.ft I
+UNIX Programmer's Manual,
+.ft
+Bell Laboratories,
+1978.
+.IP [2]
+B. W. Kernighan and
+D. M. Ritchie,
+.ft I
+The C Programming Language,
+.ft
+Prentice-Hall, 1978.
+.IP [3]
+R. Morris,
+.ft I
+A Library of Reference Standard Mathematical Subroutines,
+.ft
+Bell Laboratories internal memorandum, 1975.
+.IP [4]
+S. C. Johnson,
+.ft I
+YACC \(em Yet Another Compiler-Compiler.
+.ft
+Bell Laboratories Computing Science Technical Report #32, 1978.
+.IP [5]
+R. Morris and L. L. Cherry,
+.ft I
+DC \- An Interactive Desk Calculator.
+.ft
+.LP
+.bp
+.ft B
+.DS C
+Appendix
+.DE
+.ft
+.NH
+Notation
+.PP
+In the following pages syntactic categories are in \fIitalics\fP;
+literals are in \fBbold\fP; material in brackets [\|] is optional.
+.NH
+Tokens
+.PP
+Tokens consist of keywords, identifiers, constants, operators,
+and separators.
+Token separators may be blanks, tabs or comments.
+Newline characters or semicolons separate statements.
+.NH 2
+Comments
+.PP
+Comments are introduced by the characters /* and terminated by
+*/.
+As a non-portable extension, comments may also start with a # and
+end with a newline.
+The newline is not part of the comment.
+.NH 2
+Identifiers
+.PP
+There are three kinds of identifiers \- ordinary identifiers, array identifiers
+and function identifiers.
+All three types consist of single lower-case letters.
+Array identifiers are followed by square brackets, possibly
+enclosing an expression describing a subscript.
+Arrays are singly dimensioned and may contain up to 2048
+elements.
+Indexing begins at zero so an array may be indexed from 0 to 2047.
+Subscripts are truncated to integers.
+Function identifiers are followed by parentheses, possibly enclosing arguments.
+The three types of identifiers do not conflict;
+a program can have a variable named \fBx\fP,
+an array named \fBx\fP and a function named \fBx\fP, all of which are separate and
+distinct.
+.NH 2
+Keywords
+.PP
+The following are reserved keywords:
+.ft B
+.ta .5i 1.0i
+.nf
+ ibase if
+ obase break
+ scale define
+ sqrt auto
+ length return
+ while quit
+ for continue
+ else last
+ print
+.fi
+.ft
+.NH 2
+Constants
+.PP
+Constants consist of arbitrarily long numbers
+with an optional decimal point.
+The hexadecimal digits \fBA\fP\-\fBF\fP are also recognized as digits with
+values 10\-15, respectively.
+.NH 1
+Expressions
+.PP
+The value of an expression is printed unless the main
+operator is an assignment.
+The value printed is assigned to the special variable \fBlast\fP.
+A single dot may be used as a synonym for \fBlast\fP.
+This is a non-portable extension.
+Precedence is the same as the order
+of presentation here, with highest appearing first.
+Left or right associativity, where applicable, is
+discussed with each operator.
+.bp
+.NH 2
+Primitive expressions
+.NH 3
+Named expressions
+.PP
+Named expressions are
+places where values are stored.
+Simply stated,
+named expressions are legal on the left
+side of an assignment.
+The value of a named expression is the value stored in the place named.
+.NH 4
+\fIidentifiers\fR
+.PP
+Simple identifiers are named expressions.
+They have an initial value of zero.
+.NH 4
+\fIarray-name\fP\|[\|\fIexpression\fP\|]
+.PP
+Array elements are named expressions.
+They have an initial value of zero.
+.NH 4
+\fBscale\fR, \fBibase\fR and \fBobase\fR
+.PP
+The internal registers
+\fBscale\fP, \fBibase\fP and \fBobase\fP are all named expressions.
+\fBscale\fP is the number of digits after the decimal point to be
+retained in arithmetic operations.
+\fBscale\fR has an initial value of zero.
+\fBibase\fP and \fBobase\fP are the input and output number
+radix respectively.
+Both \fBibase\fR and \fBobase\fR have initial values of 10.
+.NH 3
+Function calls
+.NH 4
+\fIfunction-name\fB\|(\fR[\fIexpression\fR\|[\fB,\|\fIexpression\|\fR.\|.\|.\|]\|]\fB)
+.PP
+A function call consists of a function name followed by parentheses
+containing a comma-separated list of
+expressions, which are the function arguments.
+A whole array passed as an argument is specified by the
+array name followed by empty square brackets.
+All function arguments are passed by
+value.
+As a result, changes made to the formal parameters have
+no effect on the actual arguments.
+If the function terminates by executing a return
+statement, the value of the function is
+the value of the expression in the parentheses of the return
+statement or is zero if no expression is provided
+or if there is no return statement.
+.NH 4
+sqrt\|(\|\fIexpression\fP\|)
+.PP
+The result is the square root of the expression.
+The result is truncated in the least significant decimal place.
+The scale of the result is
+the scale of the expression or the
+value of
+.ft B
+scale,
+.ft
+whichever is larger.
+.NH 4
+length\|(\|\fIexpression\fP\|)
+.PP
+The result is the total number of significant decimal digits in the expression.
+The scale of the result is zero.
+.NH 4
+scale\|(\|\fIexpression\fP\|)
+.PP
+The result is the scale of the expression.
+The scale of the result is zero.
+.NH 3
+Constants
+.PP
+Constants are primitive expressions.
+.NH 3
+Parentheses
+.PP
+An expression surrounded by parentheses is
+a primitive expression.
+The parentheses are used to alter the
+normal precedence.
+.NH 2
+Unary operators
+.PP
+The unary operators
+bind right to left.
+.NH 3
+\-\|\fIexpression\fP
*** DIFF OUTPUT TRUNCATED AT 1000 LINES ***
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