b
bs(1) | bs(1) |
++ name | Increments the value of the variable (or array reference). The result is the new value. |
- - name | Decrements the value of the variable. The result is the new value. |
!expression | The logical negation of the expression. Watch out for the shell escape command. |
expression | operator expression Common functions of two arguments are abbreviated by the two argu- |
| ments separated by an operator denoting the function. Except for the assignment, concate- |
| nation, and relational operators, both operands are converted to numeric form before the |
| function is applied. |
Binary Operators (in increasing precedence):
== is the assignment operator. The left operand must be a name or an array element. The result is the right operand. Assignment binds right to left, all other operators bind left to right.
_ | _ (underscore) is the concatenation operator. |
& | & (logical AND) has result zero if either of its arguments are zero. It has result one if both |
| of its arguments are |
| zero. It has result one if either of its arguments is |
| string as a zero. |
< <= | > >= == != |
| The relational operators (<: less than, <=: less than or equal, >: greater than, >=: |
| greater than or equal, ==: equal to, !=: not equal to) return one if their arguments are in |
| the speci®ed relation, or return zero otherwise. Relational operators at the same level |
| extend as follows: a>b>c is equivalent to a>b & b>c. A string comparison is made if |
| both operands are strings. |
+ - | Add and subtract. |
* / % | Multiply, divide, and remainder. |
ÃExponentiation.
Dealing with arguments
arg(i) is the value of the
narg( ) returns the number of arguments passed. At level zero, the command argument count is returned.
Mathematical
abs(x) is the absolute value of x.
atan(x) is the arctangent of x. Its value is between −π/2 and π/2.
ceil(x) returns the smallest integer not less than x.
cos(x) is the cosine of x (radians).
exp(x) is the exponential function of x.
floor(x) returns the largest integer not greater than x.
log(x) | is the natural logarithm of x. |
rand( ) is a uniformly distributed random number between zero and one.
sin(x) is the sine of x (radians).
sqrt(x) is the square root of x.
String operations
size(s) the size (length in bytes) of s is returned.
format(f, a)
| returns the formatted value of a. f is assumed to be a format speci®cation in the style of | |
| printf(3S). Only the % ... f, % ... e, and | % ... s types are safe. Since it is not always |
Section 1−52 | − 4 − |