˙常用專用變數說明
系統內部專門創建了SYST這個STRUCTURE,裏面的欄位存放系統變數,常用的系統變數有:
SY-SUBRC : 系統執行某指令後,表示執行成功與否的變數,'0' 表示成功
SY-UNAME : 當前使用者登入SAP的USERNAME;
SY-DATUM : 當前系統日期;
SY-UZEIT : 當前系統時間;
SY-TCODE : 當前執行程式的Transaction code
SY-INDEX : 當前LOOP循環過的次數
SY-TABIX : 當前處理的是internal table 的第幾筆
SY-TMAXL : Internal table的總筆數
SY-SROWS : 螢幕總行數;
SY-SCOLS : 螢幕總列數;
SY-MANDT : CLIENT NUMBER
SY-VLINE : 畫豎線
SY-ULINE : 畫橫線
˙System fields for SCREENS.
System fields are set at the PAI (Process After Input) event for every screen.
These can be also used for interactive list processing, except for SY-DATAR, SY-LOOPC, and SY-STEPL.
SY-CUCOL : Horizontal cursor position Counting starts at column 2
SY-CUROW : Vertical cursor position Counting starts at row 1
SY-DATAR : Set to X at time of PAI if at least one screen input field was changed by the user or other data transfer, otherwise empty.
SY-LOOPC : Number of rows currently displayed in a screen table (table control).
SY-SCOLS : Number of columns in current screen.
SY-SROWS : Number of rows in current screen.
SY-STEPL : Index of current row in a screen table (table control). Is set at every loop pass. Outside a loop, for example during the POV(Process On Value Request) event for a table row, SY-STEPL is not set appropriately.
SY-TITLE : Text that appears in the title bar of the screen. For selection screens and lists this is the program name, otherwise SAP R/3. Can be set during PBO (Process Before Output) using SET TITLEBAR.
SY-UCOMM : Function code that triggered the event PAI. Every user action that triggers PAI is assigned a unique function code, with one exception: Choosing Enter triggers PAI and different function codes can be transferred to SY-UCOMM:
• If there is an entry in the command field of the standard toolbar, this is transferred to SY-UCOMM as the function code.
• If there is no entry in the command field and a function code is assigned to the ENTER key, this function code is transferred to SY-UCOMM.
• If the command field does not contain an entry and no function code is assigned to the ENTER key, it is empty and the content of SY-UCOMM is not affected.
˙Selection Screens
SY-SLSET : Variant used to fill the selection screen.
˙System Fields.
SY-SUBRC : RETURN VALUE AFTER ABAP STATEMENTS
SY-INDEX : LOOPS,CURRENT LOOP PASS
SY-TABIX : INTERNAL TABLE,CURRENT LINE INDEX
SY-TFILL : INTERNAL TABLE,CURRENT NO. OF LINES
SY-LILLI : LIST PROCESSING,CURRENT LIST LINE
SY-LSIND : LIST PROCESSING , DETAILS LIST INDEX
SY-DBCNT : DB OPERATIONS,NO. OF TABLE LINES PROCESSED
SY-CPROG : ABAP PROGRAM,CALLER IN EXTERNAL PROCEDURES
SY-DATUM : DISPLAYS CURRENT DATE
SY-DYNNR : ABAP PROGRAM,NO. OF CURRENT SCREEN
SY-TLENG : LINE LENGTH
SY-STEPL : LOOP INFORMATION IN TABLE CONTROL
SY-LOOPC : LOOP INFORMATION IN TABLE CONTROL
SY-FDPOS : CONTAINS OFF SETS FOR THE FOUND STRING
SY-DBSYS : Database system
SY-DYNGR : Screen group of current screen
SY-DYNNR : Number of current screen
SY-MSGID : Message ID
SY-MSGNO : Message number
SY-MSGTY : Message type (E,I.W,...)
SY-MSGV1 : Message variable
SY-MSGV2 : Message variable
SY-MSGV3 : Message variable
SY-MSGV4 : Message variable
SY-PAGNO : Runtime: Current page in list
SY-PFKEY : Current GUI Status
SY-COLNO : Current List Column
SY-LINCT : Page Length of List
SY-LINNO : Current Line in List
SY-LINSZ : Line width of list
SY-MACOL : Number of Columns on Left Margin of Print List
SY-BINPT : Program Running Under Batch Input
SY-MODNO : Index of External Session
˙System Fields for Date and Time.
The following system fields are always set automatically. If necessary, the GET TIME statement synchronizes the application server time with that of the database server and writes it to the system field SY-UZEIT. SY-DATUM and the system fields for the local time zone, that is SY-TIMLO, SY-DATLO, and SY-ZONLO are also reset.
SY-DATLO : Local date of user, for example 19981129, 19990628.
SY-DATUM : Current (application server) date, for example 19981130, 19990627.
SY-DAYST : During daylight saving time X, otherwise empty.
SY-FDAYW : Factory calendar weekday, Sunday 0 ... Saturday 6.
SY-TIMLO : Local time of user, for example 154353, 225312.
SY-TZONE : Time difference to Greenwich Mean Time (UTC) in seconds, for example 3600, 10800.
SY-UZEIT : Current (application server) time, for example 164353, 215312.
SY-ZONLO : Time zone of user, for example CET, UTC.
˙System Fields in Lists
SY-LSIND :Index of the list for current event for basic list = 0.
SY-LISTI : Index of the list level from which the event was triggered
SY-LILLI :Absolute number of the line from which the event was triggered
SY-LISEL :Contents of the line from which the event was triggered
SY-CUROW :Position of the line in the window from which the event was triggered (counting starts with 1)
SY-CUCOL :Position of the column in the window from which the event was triggered (counting starts with 2)
SY-CPAGE :Page number of the first displayed page of the list from which the event was triggered
SY-STARO :Number of the first line of the first page displayed of the list from which the event was triggered (counting starts with 1). This line may contain the page header.
SY-STACO :Number of the first column displayed in the list from which the event was triggered (counting starts with 1)
SY-UCOMM :Function code that triggered the event
SY-PFKEY :Status of the list currently being displayed.
來源：
http://wiki.scn.sap.com/wiki/display/ABAP/ABAP+system+fields#ABAPsystemfields-SystemfieldsforSCREENS
