express17 - Man Page

express17 [Options] EXPRESSION [TYPE NAME VALUE]...

express17 prints the value of EXPRESSION to standard output.  EXPRESSION may refer variables defined as a TYPE NAME VALUE triplet.  TYPE may be one of cardinal (integral, positive), integer (integral), real (real) and text (string).

-P,  --print

Print the parsed expression instead its value.

-t,  --type

Print the expression type instead its value.

--list

List functions and exit.

--list-1

List unary operators and exit.

--list-2

List binary operators and exit.

--list-2h

List binary operators and exit.

--list-3

List ternary operators and exit.

--list-3h

List ternary operators and exit.

--help

Print a usage message and exit with a status code indicating success.

--version

Print version information on standard output then exit.

The allowed expression syntax is similar to that of C expressions.  It allows for prefix unary and common syntax binary operators, functions and variables.  There are four supported types: cardinal (integral, positive), integer (integral), real (real) and text (string).

The available functions are mathematical or text generalities, among which:

real Gacos(real x);

is the in degrees specified arc cosine of x

real Gadiff(real x, real y);

is the in degrees specified smallest angle between degrees x and degrees y (or something)

real Garccos(real x);

is same as Gacos(x)

real Garcctg2(real x, real y);

is the in degrees specified arc tangent of y / x, signs of both x and y being used to determine the quadrant of the result (same as Gatan2(y, x))

real Garcdiff(real x, real y);

is same as Gadiff(x, y)

real Garcsin(real x);

is same as Gasin(x)

real Garctg(real x);

is same as Gatan(x)

real Garctg2(real y, real x);

is same as Gatan2(y, x)

real Gasin(real x);

is the in degrees specified arc sine of x

real Gatan(real x);

is the in degrees specified arc tangent of x

real Gatan2(real y, real x);

is the in degrees specified arc tangent of y / x, signs of both x and y being used to determine the quadrant of the result

real Gcos(real x);

is the cosine of degrees x

real Gparcctg2(real x, real y);

is the positively defined, in radians specified arc tangent of y / x, signs of both x and y being used to determine the quadrant of the result (same as Gpatan2(y, x))

real Gparctg2(real y, real x);

is same as Gpatan2(y, x)

real Gpatan2(real y, real x);

is the positively defined, in degrees specified arc tangent of y / x, signs of both x and y being used to determine the quadrant of the result

real Gsin(real x);

is the sine of degrees x

real Gtan(real x);

is the tangent of degrees x

real Gtg(real x);

is same as Gtan(x)

integer abs(integer m);

is the absolute value of m

real acos(real x);

is the in radians specified arc cosine of x

real adiff(real x, real y);

is the in radians specified smallest angle between radians x and radians y (or something)

real arccos(real x);

is same as acos(x)

real arcctg2(real x, real y);

is the in radians specified arc tangent of y / x, signs of both x and y being used to determine the quadrant of the result (same as atan2(y, x))

real arcdiff(real x, real y);

is same as adiff(x, y)

real arcsin(real x);

is same as asin(x)

real arctg(real x);

is same as atan(x)

real arctg2(real y, real x);

is same as atan2(y, x)

real asin(real x);

is the in radians specified arc sine of x

real atan(real x);

is the in radians specified arc tangent of x

real atan2(real y, real x);

is the in radians specified arc tangent of y / x, signs of both x and y being used to determine the quadrant of the result

integer base2(integer m);

is the greatest power of 2 less than or equal to m if m is not less than zero, some undefined value otherwise

integer bcount(integer m);

is the m bit count (i.e. the number of bits set in m)

real ceil(real x);

is the up rounded value of x

cardinal cardinal(cardinal z);

is z

integer character(text s, integer m);

is the (positively defined value of the) mth character of s, if such character exists, 0 otherwise (negative position indications are interpreted with respect to the end of string)

integer compare(text s, text t);

is 0 if s is (case sensitive) same as t, less than 0 if s is less than t and greater than 0 if s is greater than t

real cos(real x);

is the cosine of radians x

integer deck2(integer m);

is the lesser power of 2 greater than or equal to m if m is not less than zero, some undefined value otherwise

integer drand(integer m);

is a pseudo-random integer between inclusive 0 and m

text echo(text s);

is s

real exp(real x);

is the value of e (the base of natural logarithms) raised to the power of x

real exp2(real x);

is the value of 2 raised to the power of x

real fabs(real x);

is the absolute value of x

real fclip(real min, real x, real max);

is the minimum between max and the maximum between x and min

integer ffs(integer m);

is the 1 based position of the first (least significant) bit set in m if any, 0 otherwise

real floor(real x);

is the down rounded value of x

integer fls(integer m);

is the 1 based position of the last (most significant) bit set in m if any, 0 otherwise

real fmax(real x, real y);

is the maximum of x and y

real fmin(real x, real y);

is the minimum of x and y

real fmod(real x, real y);

is the remainder of dividing x by y, more specifically x - n * y, where n is the quotient of x / y, rounded toward zero to an integer

real fmodf(real x);

is the same sign as x fractional part of x

integer frame(text s, integer c);

is the position of the last occurrence of the c non zero character in the s string if any, -1 otherwise

real frand(void);

is a pseudo-random real between 0 and 1

real frexp(real x, integer &e);

is the (-1; -0.5], [0.5; 1) normalized fraction that multiplied by the power of two to which e is set retrieves x

real fsign(real x);

is -1 if x is negative, 0 of x is zero, 1 otherwise

integer gcd(integer m, integer n);

is the greatest common denominator of m and n

real gclip(real x, real min, real max);

is the minimum between max and the maximum between x and min

integer iclip(integer min, integer m, integer max);

is the minimum between max and the maximum between m and min

real imodf(real x);

is the same sign as x integral part of x

integer integer(integer m);

is m

integer irand(integer m, integer n);

is a pseudo-random integer between inclusive m and n

integer jclip(integer m, integer min, integer max);

is the minimum between max and the maximum between m and min

integer kfs(integer m, integer k);

is the 0 based position of the first kth (least significant) bit set in m if any, the number of bits in m otherwise (kfs(m, 0) is equivalent with xfs(m))

integer kls(integer m, integer k);

is the 0 based position of the last kth (most significant) bit set in m if any, the number of bits in m otherwise (kls(m, 0) is equivalent with xls(m))

integer length(text s);

is the length of s

real limit(real x);

is the away from zero rounded value of x

real ln(real x);

is same as log(x)

real log(real x);

is the natural logarithm of x

real log10(real x);

is the base 10 logarithm of x

real log2(real x);

is the base 2 logarithm of x

real lrand(void);

is a pseudo-random real between -1 and 1

integer lz(integer m);

is the m leading zero bits count, same as xls(m)

integer match(text s, text t);

is 0 if t wild card (case sensitive) matches the s pattern (the * and ? literal sign are interpreted as for their shell pattern equivalents), non 0 otherwise

integer max(integer m, integer n);

is the maximum of m and n

integer min(integer m, integer n);

is the minimum of m and n

real modf(real x, real &y);

is the same sign as x fractional part of x, y is the same sign as x integral part of x

real parcctg2(real x, real y);

is the positively defined, in radians specified arc tangent of y / x, signs of both x and y being used to determine the quadrant of the result (same as patan2(y, x))

real parctg2(real y, real y);

is same as patan2(y, x)

real patan2(real y, real x);

is the positively defined, in radians specified arc tangent of y / x, signs of both x and y being used to determine the quadrant of the result

integer place(text s, integer c);

is the position of the first occurrence of the c non zero character in the s string if any, -1 otherwise

real pow(real x, real y);

is the value of x raised to the power of y

text project(text s, integer m);

is s after position m (negative position indications are interpreted with respect to the end of string)

real real(real x);

is x

real round(real x);

is the towards nearest integer, half cases away from zero rounded value of x

integer sign(integer m);

is -1 if m is negative, 0 of m is zero, 1 otherwise

integer signed(cardinal z);

is z

real sin(real x);

is the sine of radians x

real sq(real x);

is the square of x

real sqrt(real x);

is the square root of x

real tan(real x);

is the tangent of radians x

real tg(real x);

is same as tan(x)

real track(real x);

is the towards zero rounded value of x

integer tz(integer m);

is the m trailing zero bits count, same as xfs(m)

cardinal unsigned(integer m);

is m

integer xfs(integer m);

is the 0 based position of the first (least significant) bit set in m if any, the number of bits in m otherwise (same as tz(m))

integer xls(integer m);

is the 0 based position of the last (most significant) bit set in m if any, the number of bits in m otherwise (same as lz(m))

Most of prefix unary and common syntax binary C operators are supported (including unary !, +, - and ~ and binary *, /, %, +, -, <<, >>, <, >, <=, >=, !=, ==, &, ^, |, &&, ||, =, +=, -=, *=, /=, %=, &=, ^=, |=, <<= and >>=), the semantics and precedence being the same or at least very close to those of their C counterparts.

Ciprian Niculescu

aime(1), logique44(1), logique48(1), logique49(1).