Using Variable Parameters

The statements read from command files by the call command and the command strings associated with command aliases and event traps can contain references to variable parameters. Each command accepted by the debugger from command files, command aliases and event traps is scanned for the presence of equal signs (=) which mark the start of variable parameter references.

An equal sign followed by one or more digits is a reference to a parameter from the call command, alias command or event. An equal sign followed by an alphabetic character and zero or more alphanumeric characters is a reference to an operating system environment variable. The variable name in the command, including the equal sign and a trailing period if present, is replaced by the variable parameter’s value. If a variable parameter is not assigned a value, the variable name is replaced by the empty string, removing it from the command. If the SYSDIR environment variable is not set, a reference to the =SYSDIR variable is replaced by the name of the directory containing the j390 program.

Two consecutive equal signs are replaced by a single equal sign. This is important for set alias commands in command files since substitution of variable parameter names is performed twice. Substitution is performed once before the set alias command is processed using the parameters on the call command and it is performed again when the alias is used.

Any characters following the command file name on the call command are first separated into groups by blank characters and then assigned to the numbered variable parameters starting with =1. Double quotes may be used to delimit string parameters containing any characters, including blanks. The command file name is assigned to the variable named =0. For example:

Will cause the following variable assignments:

For alias commands, the number of parameters removed from the entered command and assigned to variables is defined in the set alias command. The name of the alias is assigned to the =0 variable. Any characters not removed from the entered command will be appended to the command string associated withe the alias. For example, if the command alias SETSTR is defined using:

Then the command Will result in the following commands being executed:

For load events, two parameters are defined:

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Last modified on November 30, 2005