Scripting variable not defined error during batch job

Question: I'm trying to execute a batch script which includes a SQLCMD

SQLCMD -E -d master -S %1 -i "SQL_AGENT_JOBS_INSTALL.sql"

The sql script includes a reference to a SQL AGENT token SQLLOGDIR. 

When I run the same script from SSMS it all work OK, but executing it through the batch\ SQLCMD route throws this error. 

How can I fix this issue?

Answer:   To pass a variable into SQLCMD use the -v switch. 

the format is : -v var = "value"

Extending the example used above : 

SQLCMD -E -d master -S %1 -v SQLLOGDIR="" JOBNAME="" STEPID="" STRTDT="" STRTTM="" -i "SQL_AGENT_JOBS_INSTALL.sql"
PAUSE

This is a workaround - and the problem suggests the sql script is attempting to capture values from within the SQL Server environment - but as this is running as a batch job the values are set prior to the interaction with SQL Server.

For more SQLCMD related reading 

How to capture errors from SQLCMD (SQL Server DBA)

SQLCMD and blank password

SQL Server - SQLCMD with screen output and output file