PC(1)                                                       PC(1)

     NAME
          pc - programmer's calculator

     SYNOPSIS
          pc [ -n ]

     DESCRIPTION
          Pc is an arbitrary precision calculator with a special
          emphasis on supporting two's complement bit operations and
          working with different number bases.

          Pc reads input statements which are either expressions or
          control statements.  Multiple statements in one line can be
          separated by semicolons.  Pc prints the value of all expres-
          sions that are not terminated by a semicolon.

          Pc can be run non-interactively by using the -n switch. In
          this case no input prompt is printed.

          Expressions can use the C-like operators

          + - * ** (exponentiation)

          / % (Euclidean division, by default)

          & | ^ ~ ! << >>

          && || (returning the second argument, if appropriate)

          < >= < <= == !=

          Variables can be defined using =.  The builtin variable @
          always refers to the last printed result.

          Numbers can use the prefixes 0b (binary), 0 (octal), 0d
          (decimal) and 0x (hexadecimal).  _ in numbers can be added
          for readability and is ignored.

        Builtin functions
          bin(n)                Display n in binary.
          oct(n)                Display n in octal.
          dec(n)                Display n in decimal.
          hex(n)                Display n in hexadecimal.
          pb(n, b)              Display n in base b (currently must be
                                one of 0, 2, 8, 10, 16; 0 uses the
                                defined output base).
          abs(n)                Absolute value of n.
          round(n,m)            n rounded to the nearest multiple of
                                m.  Numbers exactly halfway between
                                are rounded to the next even multiple.

     PC(1)                                                       PC(1)

          floor(n,m)            n rounded down to the next multiple of
                                m.
          ceil(n,m)             n rounded up to the next multiple of
                                m.
          trunc(n,m)            n truncated to m bits.
          xtend(n,m)            n truncated to m bits, with the high-
                                est bit interpreted as a sign bit.
          rev(n,m)              n truncated to m bits, with the order
                                of bits reversed.
          ubits(n)              The minimum number of bits required to
                                represent n as an unsigned number.
          sbits(n)              The minimum number of bits required to
                                represent n as an signed number.
          nsa(n)                The number of bits set in n.
          cat(a0,n0,...,aN,nN)  Truncate each of the ai arguments to
                                ni bits and concatenate their binary
                                representation.
          gcd(n,m)              The greatest common divisor of n and
                                m.
          minv(n,m)             The inverse of n mod m.
          rand(n)               A random number satisfying 0 ≤ rand(n)
                                < n.

        Control statements
          Control statements are always evaluated with default input
          base 10.

          _ n  If n ≠ 0, insert _ in all printed numbers, every n dig-
               its.

          < n  Set the default input base to n (default 10).  The
               input base can always be overriden by the base prefixes
               defined above.

          > n  Set the output base to n.  If n = 0 (default), print
               each number in the base it was input in.

          / 0  Use Euclidean division (default).  a / b is rounded
               towards ± (opposite sign as b).  a % b is always non-
               negative.

          / 1  Use truncating division (same as C).  a / b is rounded
               towards zero.  a % b can be negative.

          ' 1  Enable numbering bits (disable with 0).  If the base is
               a power of two, print the number of the corresponding
               bit above each digit.

     SOURCE
          /sys/src/cmd/pc.y

     SEE ALSO

     PC(1)                                                       PC(1)

          bc(1), hoc(1)

     BUGS
          With the input base set to 16, terms such as ABC are ambigu-
          ous.  They are interpreted as numbers only if there is no
          function or variable of the same name.  To force interpreta-
          tion as a number, use the 0x prefix.

          Arbitrary bases should be supported, but are not supported
          by the mp(2) string functions.

     HISTORY
          Pc first appeared in 9front (August, 2016).