Expressions and operators in REXX EXECs
An expression combines variables, whole numbers, and character strings with operators. For example, the following EXEC statement uses the comparative operator = in an expression with the REXX IF conditional statement to compare the first character of the character string in the Z1 symbol to the value in the CMD symbol:
IF CMD = SUBSTR(Z1,1,1) THEN ...
The function SUBSTR is a built-in REXX function that replaces the function call with specific characters from a character string. The actual characters are selected by specifying a starting position and a length for the portion of the character string to be used.
In this example, SUBSTR is replaced with the first character of the character string substituted for the Z1 symbol.
Tip: For faster searching, add an asterisk to the end of your partial query. Example: cert*