Concatenating Strings and String Substitution

You can concatenate a string with a pre￿x or su￿x. String substitution in a Command File or a UDC parameter tak es precedence over substitution of Command In terpreter-level variables. For example,

:SETVAR x 1 :WHILE x < 10 DO

:PURGE ACCT!x :SETVAR x x+1

:ENDWHILE :DELETEVAR x

purges ￿les ACCT1, ACCT2, . . . , ACCT9.Expression Evaluation

You can specify an expression in a Command File or a UDC parameter and an appropriate value will be assigned to it.

Using Job Control Words (JCWs)

A Job Control Word (JCW) is one t ype of prede￿ned variable. On MPE/iX, JCWs are a subset of session-lev el variables, restricted b y values and naming con ventions. MPE/iX stores JCWs as integers in the session-lev el variable table. You can manipulate JCWs with

JCW commands and in trinsics Variable commands and in trinsics IF command

The commands SETJCW and SHOWJCW correspond to the commands SETVAR and SHOWVAR used on standard variables. DELETEVAR is used to delete JCWs. The in trinsics GETJCW and PUTJCW correspond to the in trinsics HPCIGETVAR and HPCIPUTVAR used on CI variables. MPE/iX distinguishes bet ween the table entries created by the SETJCW command (or the PUTJCW intrinsic) and those created b y the SETVAR command (or the HPCIPUTVAR intrinsic).

JCW commands and in trinsics usually function like the corresponding v ariable commands and intrinsics, with a few exceptions, described belo w.

Job Control Word Name and Type

A JCW name can be a maximum of 255 c haracters long. The ￿rst c haracter must be alphabetic. Other c haracters can be alphabetic or n umeric. A JCW name cannot con tain the underscore (_) or the wildcard parameters (#, ?, [, and ]). A JCW m ust be of type integer, with a value in the range 0 to 65535. This is the only di￿erence bet ween JCW names and variable names. For detailed information on naming and dereferencing v ariables, refer to Command Interpreter Access and Variables Programmer's Guide (32650-90011).

Changing the Value of a JCW

Once created, you can change the value of a JCW by using variable or JCW commands and intrinsics. If you assign a value to a JCW that is outside the v alid JCW range, then MPE/iX reclassi￿es it as a standard v ariable when you assign suc h a string value to it. You can no longer use JCW commands and in trinsics on it; y ou must use variable commands and

2-2 Utilities and Tools