UNLOCK

Release a record lock on a channel

WTSupported in traditional Synergy on Windows

WNSupported in Synergy .NET on Windows

USupported on UNIX

VSupported on OpenVMS

UNLOCK channel[, RFA:match_rfa]

Arguments

channel

The channel on which the file is open. (n)

RFA

(optional) Unlocks the record with the specified RFA. See RFA for a complete description.

Discussion

The UNLOCK statement releases an automatic lock on the specified channel or a lock specified by the RFA.

This statement is ignored if no lock conditions exist on the specified channel.

See also

• FREE routine
• Record locking

Examples

The following subroutine unlocks both automatic and manual locks.

subroutine rel_locks
    a_chn               ,n
    a_rfa               ,a
proc
    if (^passed(a_rfa)) then
      unlock a_chn, RFA:a_rfa
    else
      unlock a_chn
    xreturn
endsubroutine

The following example reads and locks a relative record, and then prompts the user to add a new record, change the locked record, delete the locked record, or exit the routine. If the user selects exit or presses the EOF character, the ­record is explicitly unlocked.

subroutine proc_rec
    a_chn               ,d              ;Channel of file open in update mode
    a_data              ,a              ;Data record to read
    a_recnum            ,d              ;Record number to read
.define TTCHN           ,1
record
    ans                 ,a1
proc
    read(a_chn, a_data, a_recnum) ;Record locked
    repeat
      begin
        display(TTCHN, "Add/Change/Delete/Exit: ")
        reads(TTCHN, ans, exit)
        case ans of
          begincase
          "A":
            xcall add
          "C":
            xcall change
          "D":
            xcall delete
          "E":
            exitloop
          endcase
      end
exit,
    unlock a_chn
    xreturn
endsubroutine