The CBL_READ_SCR_CHARS routine is one of a set of library routines that facilitate reading and writing attributes on the screen. This routine reads a string of characters from the screen.
CALL "CBL_READ_SCR_CHARS" USING SCREEN-POSITION, CHARACTER-BUFFER, STRING-LENGTH RETURNING STATUS-CODE
SCREEN-POSITION Group item | Group item is defined as follows:
01 SCREEN-POSITION. 03 ROW-NUMBER PIC X COMP-X. 03 COLUMN-NUMBER PIC X COMP-X. On entry, contains the screen position at which to start reading (the top left corner is row 0, column 0) |
CHARACTER-BUFFER PIC X(N). | On exit, this data item contains the characters read from the screen. It must be at least the length specified by STRING-LENGTH. Positions in the data item beyond that length are unchanged. |
STRING-LENGTH PIC XX COMP-X. | On entry, contains the length of the string to read
On exit, contains the length of the string read when the end of the screen is reached |
STATUS-CODE Any numeric type | Returns 1 if successful, or 0 if not successful |
This library routine uses SCREEN-POSITION (in row and column coordinates) to determine the location to start the read operation. STRING-LENGTH specifies the length of the string of characters to be read, starting from SCREEN-POSITION. When the routine exits, CHARACTER-BUFFER contains the string of characters read.