Caché ObjectScript Reference - InterSystems Documentation

A single-character read accepts a single input character and stores its ASCII decimalequivalent in the specified variable. It stores the character itself in the $ZB and $KEYspecial variables. Input concludes automatically when a single character is input. A terminatorcharacter is considered a single-character input, and is stored as such. A timeoutsets variable to –1.ArgumentspcAn optional postconditional expression. Caché executes the command if the postconditionalexpression is true (evaluates to a non-zero numeric value). Caché does not execute the commandif the postconditional expression is false (evaluates to zero). For further details, referto Command Postconditional Expressions in Using Caché ObjectScript.variableThe local variable, process-private global, or global that is to receive the input data. It canbe either unsubscripted or subscripted. If a specified variable does not already exist, Cachédefines it at the beginning of the READ operation. If a specified variable is defined and hasa value, Caché clears this value at the beginning of the READ operation. When you inputcharacters, they are stored in variable as they are input; therefore if a read operation is interruptedby a timeout, the characters typed up to that point are stored in variable. (However,note the behavior of variable upon a encountered a interrupt, as described below.)Non-printing characters (such as ) are stored in variable. A terminator character canbe used to conclude any type of read operation. For example, from a terminal, you press the key to conclude a read operation. This terminator character is not stored in variablefor a variable-length or fixed-length read. The terminator character is stored in variable fora single-character read.nREADA positive integer specifying the maximum number of characters to accept for a fixed-lengthread. The READ completes either when the specified number of characters is input, or whenit encounters a terminator character. This argument is optional, but if specified the preceding# symbol is required.Specifying zero or a negative number results in a error. However, leading zerosand the fractional portion of a number are ignored, and the integer portion used. You canspecify n as a variable or an expression that resolve to an integer.Caché ObjectScript Reference 117