OSF DCE Administration Guide--Core Components

Using the DCE Control Program Command Language

dcecp> expr ($x-8)*2

dcecp> expr $x-(8*2)

dcecp> expr $x-8*2

dcecp>

Be careful using variables in expressions; variables like $x must be numeric strings like

24, not nonnumeric strings like 4*6.

The DCE control program normally treats numbers as decimal integers, but can read

numbers in octal and hexadecimal formats too. Precede a number with 0 (zero) for octal

interpretation, as in 0477. Precede a number with 0x for hexadecimal interpretation, as in

0x9FF. You can also represent numbers in ﬂoating-point format by using any of the

forms speciﬁed by the ANSI C standard (with the exception of the f, F, l, and L sufﬁxes).

The DCE control program also supports numerous mathematical functions in expressions

such as cos, exp, log, tan, sin, and others, by invoking the C math library functions of the

same name.

Here’s a partial list of operators you can use with the expr command. The list order also

denotes precedence. This means, for instance, that expr multiplies before adding (2+2*4

equals 10).

- unary minus

~ bitwise NOT

! logical NOT

* multiply

/ divide

% remainder

+ add

- subtract

<< left shift

>> right shift

< Boolean less than

<= Boolean less than or equal

> Boolean greater than

>= Boolean greater than or equal

== Boolean equal

!= not equal

& bitwise AND

^ bitwise exclusive OR

| bitwise OR

&& logical AND

|| logical OR

a?b:c if-then-else (as in C).

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