`UADD` — `USUB`

UADD — Adds two unsigned integers
UNLOADM — Unloads a module
UNTIL — See DO
UPDATE — Deletes the current record and saves as a new record at the end of the file
UPPER$ — Converts a string to upper case
USE — Selects a data file
USUB — Subtracts two unsigned integers

`UADD` — Adds two unsigned integers

Usage: i%=UADD(val1%, val2%)

Add val1% and val2%, as if both were unsigned integers with values from 0 to 65535. Prevents integer overflow for pointer arithmetic when the 64K memory restriction is set (see SETFLAGS), e.g. UADD(ADDR(text$),1) should be used instead of ADDR(text$)+1.

One argument would normally be a pointer and the other an offset expression.

Note that UADD and USUB should not be used on the for pointer arithmetic unless SETFLAGS has been used to enforce the 64K memory limit. In general, long integer arithmetic should be used for pointer arithmetic.

`UNLOADM` — Unloads a module

Usage: UNLOADM module$

Removes from memory the module module$ loaded with LOADM.

module$ is a string containing the name of the translated module.

The procedures in an unloaded module cannot then be called by another procedure.

UNLOADM causes any procedures in the module that are not still running to be unloaded from memory too. Running procedures are unloaded on return. It is considered bad practice, however, to use UNLOADM on a module with procedures that are still running.

Once LOADM has been called, procedures loaded stay in memory until the module is unloaded. Modules are not flushed automatically.

`UNTIL` — See `DO`

See DO.

`UPDATE` — Deletes the current record and saves as a new record at the end of the file

Usage: UPDATE

Warning: This function is deprecated and included only for compatibility with older versions of the OPL language. INSERT, PUT, and CANCEL should be used in preference to APPEND and UPDATE, although APPEND and UPDATE are still supported. However, note that APPEND can generate a lot of extra (intermediate) erased records. COMPACT should be used to remove them, or alternatively use SETFLAGS to set auto-compaction on.

Deletes the current record in the current data file and saves the current field values as a new record at the end of the file.

This record, now the last in the file, remains the current record.

Example:

    A.count=129
    A.name$="Brown"
    UPDATE

Use APPEND to save the current field values as a new record.

`UPPER$` — Converts a string to upper case

Usage: u$=UPPER$(a$)

Converts any lower case characters in a$ to upper case, and returns the completely upper case string. Example:

    ...
    CLS :PRINT "Y to continue"
    PRINT "or N to stop."
    g$=UPPER$(GET$)
    IF g$="Y"
          nextproc:
    ELSEIF g$="N"
          RETURN
    ENDIF
    ...

Use LOWER$ to convert to lower case.

`USE` — Selects a data file

Usage: USE logical name

Selects the data file with the given logical name (A-Z). The file must previously have been opened with OPEN, OPENR or CREATE and not yet be closed.

All the record handling commands (such as POSITION and UPDATE, and GOTOMARK, INSERT, MODIFY, CANCEL and PUT) then operate on this file.

`USUB` — Subtracts two unsigned integers

Usage: i%=USUB(val1%,val2%)

Subtract val2% from val1%, as if both were unsigned integers with values from 0 to 65535. Prevents integer overflow for pointer arithmetic when the 64K memory restriction is set (see SETFLAGS)

Note that UADD and USUB should not be used for pointer arithmetic unless SETFLAGS has been used to enforce a 64K memory limit. In general long integer arithmetic should be used.

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