OSF DCE Administration Guide--Core Components

Using the DCE Control Program Command Language

Here we ﬁrst set variable a to 7. In line 2, we use the expr command to add 2 to the

value of a (7). The dollar sign triggers dcecp to insert the value 7. The last line shows

the return value from the expr command.

A more relevant example might be

dcecp> set a /.:/sec

/.:/sec

dcecp> object show $a

{RPC_ClassVersion

{01 00}}

{RPC_ObjectUUIDs

{06 3b 23 00 72 e5 e0 1d 8c b4 00 00 c0 8a df 56}}

{RPC_Group

{2f 2e 2e 2e 2f 77 61 72 64 5f 63 65 6c 2e 6f 73 66 2e 6f 72

67 2f 73 75 62 73 79 73 2f 64 63 65 2f 73 65 63 2f 6d 61 73 74

65 72 00}}

{CDS_CTS 1994-05-23-17:21:37.481+00:00I0.000/00-00-c0-8a-df-56}

{CDS_UTS 1994-05-23-17:22:36.607+00:00I0.000/00-00-c0-8a-df-56}

{CDS_Class RPC_Group}

{CDS_ClassVersion 1.0}

dcecp>

Remove (undeﬁne) a variable by using the unset command as in the following example:

dcecp> unset a

dcecp> set a

Error: can’t read "a": no such variable

dcecp>

2.3 Command Substitution

Command substitution provides a convenient way to express the return value of one

command within another command. This is useful when you want to use the return value

of one command as input to another command. Use brackets to invoke command

substitution. The following example uses the expr command, which we’ll discuss

shortly. Generally, expr performs a math function, returning the computed value

expressed by its arguments, as shown:

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