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ENVVARS Section

Overview:

ENVVARs are values used in text substitution elsewhere in the input. DSM2 attempts to replace any text that is preceded by a "$" and wrapped in curly braces: ${EXAMPLE}. By convention, these variables are always used in upper case. The substitution will be made from either system environmental variables or pseudo-environmental variables defined in this section. For instance, the SCALAR input section might indicate that run_start_time be set to ${START_TIME}. DSM2 will then search the system environmental variables and user-specified environmental variables for START_TIME and substitute the value (or print a warning if it finds nothing).

ENVVARs can be specified in text, or set by manipulating the command environmental variables. In production runs, many of the ENVVARs are set in a special file called the "configuration" file. Such a file is often included in the main input file using the CONFIGURATION include block.

Reference

Keyword Descriptions

NAME

Name of the envvar. This is the alias that will be used elsewhere in the input system where the substitution is desired. For instance, if the NAME is START_TIME, ${START_TIME} would be used elsewhere.

VALUE

Value assigned during substitution. For instance, for an ENVVAR with name START_TIME, a likely value would be "0000".

Table Info

Identifier:

NAME

Include Block:

CONFIGURATION

Examples:

Definition and use: The following example defines an ENVVAR section and then uses the variables later in a SCALAR section.

ENVVARS        
NAME    VALUE   
START_DATE  01JAN1990   # Runtime using envvars
END_DATE    01JAN2001   
START_TIME  0000    
END_TIME    0000    
END


SCALAR      
model_name  historical_hydro    
run_start_date  ${START_DATE}   
run_end_date    ${END_DATE} 
run_start_time  ${START_TIME}   
run_end_time    ${END_TIME} 
END

Identifier:Table Info

NAME

Parent Table:

Table is parent

Include Block:

CONFIGURATION

  • ENVVARs can also be used on each other -- in text input that occurs after the ENVVAR definition.

    ENVVARS
    NAME VALUE
    DSM2MODIFIER historical_v81 #Study name used for DSM2 output

    Output

    OUTPUTFILE ${DSM2MODIFIER}.dss

    hydro

    HYDROOUTDSSFILE ${DSM2OUTPUTDIR}/${OUTPUTFILE} END