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 NAME     
 |  |  |  | bc – arbitrary-precision arithmetic language 
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 SYNOPSIS     
 |  |  |  | bc [ −c ] [ −l ] [ −s ] [ file ... ] 
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 DESCRIPTION     
 |  |  |  | Bc is an interactive processor for a language that resembles C
    but provides arithmetic on numbers of arbitrary length with up
    to 100 digits right of the decimal point. It takes input from
    any files given, then reads the standard input. The −l argument
    stands for the name of an arbitrary precision math library. The
    −s argument suppresses the automatic
    display of calculation results; all output is via the print command.
    
    
    
    The following syntax for bc programs is like that of C; L means
    letter a-z, E means expression, S means statement. Lexical
 
 Names|  |  |  | |  |  |  | comments are enclosed in /* */ newlines end statements
 
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 Other operands|  |  |  | |  |  |  | simple variables: L array elements: L[E]
 The words ibase, obase, and scale
 
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 Operators|  |  |  | |  |  |  | arbitrarily long numbers with optional sign and decimal point. (E)
 sqrt(E)
 length(E)
 number of significant decimal digits
 scale(E)
 number of digits right of decimal point
 L(E,...,E)
 function call
 
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 Statements|  |  |  | |  |  |  | +    −    *    /    %    ^  (% is remainder; ^ is power) ++    −−
 ==    <=    >=    !=    <    >
 =    +=    −=    *=    /=    %=    ^=
 
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 Function definitions|  |  |  | |  |  |  | E { S ; ... ; S }
 print E
 if ( E ) S
 while ( E ) S
 for ( E ; E ; E ) S
 null statement
 break
 quit
 "text"
 
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 Functions in   −l math library|  |  |  | |  |  |  | define L ( L , ... , L ){ auto L , ... , L
 S ; ... ; S
 return E 
            
            
            }
 
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 All function arguments are passed by value. 
    
    
    The value of an expression at the top level is printed unless
    the main operator is an assignment or the −s command line argument
    is given. Text in quotes, which may include newlines, is always
    printed. Either semicolons or newlines may separate statements.
    Assignment to scale influences the number of digits to be retained
    on arithmetic operations
    in the manner of dc(1). Assignments to ibase or obase set the
    input and output number radix respectively. 
    
    
    The same letter may be used as an array, a function, and a simple
    variable simultaneously. All variables are global to the program.
    Automatic variables are pushed down during function calls. In
    a declaration of an array as a function argument or automatic
    variable empty square brackets must follow the array name. 
    
    
    Bc is actually a preprocessor for dc(1), which it invokes automatically,
    unless the −c (compile only) option is present. In this case the
    dc input is sent to the standard output instead.|  |  |  | |  |  |  | s(x)   sine c(x)   cosine
 e(x)   exponential
 l(x)   log
 a(x)   arctangent
 j(n, x)
 Bessel function
 
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 EXAMPLE     
 |  |  |  | Define a function to compute an approximate value of the exponential.
    Use it to print 10 values. (The exponential function in the library
    gives better answers.) 
    
    
    scale = 20 define e(x) {
 
 }|  |  |  | auto a, b, c, i, s a = 1
 b = 1
 s = 1
 for(i=1; 1; i++) {
 
 }|  |  |  | a *= x b *= i
 c = a/b
 if(c == 0) return s
 s += c
 
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 for(i=1; i<=10; i++) print e(i)
 
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 FILES     
 SOURCE     
 SEE ALSO     
 BUGS     
 |  |  |  | No &&, ||, or ! operators. 
    
    
    A for statement must have all three Es. 
    
    
    A quit is interpreted when read, not when executed. 
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