.TITLE SUBROUTINE ENTER .SBTTL DOCUMENTATION ; ; AUTHOR T G KELLY ; DEPARTMENT OF PATHOLOGY ; UNIVERSITY OF SOUTH ALABAMA ; ; DATE 26-JAN-78 ; ; THIS SUBROUTINE CHECKS FOR AN ALREADY EXISTING FILE ; BY THE FILE NAME ENTERED AT THE KEYBOARD. ; IF IT EXISTS, IT TAKES AN ERROR RETURN. IF IT IS ; NOT PRESENT, A FILE IS OPENED UNDER THAT NAME USING ; CHANNEL 0. ; ; SEE VECTOR.MAC FOR FURTHER DOCUMENTATION ; .SBTTL MACRO CALLS ; .MCALL ..V2..,.REGDEF ..V2.. ;VERSION 2 MACROS .REGDEF ;DEFINE REGISTERS .MCALL .ENTER,.LOOKUP,.PRINT .GLOBL LIST,OUTPUT,ENTER,FILSPC,LENGTH ; .SBTTL MAIN ; ENTER: .LOOKUP #LIST,#0,#FILSPC ;SEE IF FILE ALREADY EXISTS BCS OPEN MOV #3,R0 ;FILE ALREADY EXISTS RTS R5 ;RETURN WITH ERROR IN R0 OPEN: .ENTER #LIST,#0,#FILSPC,LENGTH ;ENTER FILE NAME BCC RETURN MOV @#52,R0 ;FETCH ERROR WORD INC R0 RTS R5 ;RETURN WITH ERROR IN R0 RETURN: CLR R0 RTS R5 .END