NAME¶

read-fifo - (FIFO)

PURPOSE¶

Reads key/value pair from a FIFO list.

SYNTAX¶

read-fifo <list> \


    key <key> \


    value <value> \


    [ status <status> ]

DESCRIPTION¶

read-fifo retrieves an element from the FIFO <list> into <key> string (in "key" clause) and <value> string (in "value" clause).

Once an element has been retrieved, the next use of read-fifo will obtain the following one, in the same order they were put in. read-fifo starts with the first element put in, and moves forward from there, unless rewind-fifo is called, which positions back to the first one.

If the element is successfully retrieved, <status> number (in "status" clause) is GG_OKAY, otherwise it is GG_ERR_EXIST, which means there are no more elements to retrieve.

EXAMPLES¶

In this example, a FIFO list is created, and two key/value pairs added. They are then retrieved in a loop and printed out (twice with rewind), and then the list is purged:

// Create a list
new-fifo mylist
// Add data to the list
write-fifo mylist key "key1" value "value1"
write-fifo mylist key "some2" value "other2"
start-loop


    // Get data from the list


    read-fifo mylist key k value v status st


    // Check if no more data


    if-true st not-equal GG_OKAY


        break-loop


    end-if


    @Obtained key <<print-out k>> with value <<print-out v>>
end-loop
// Go through the list again, use rewind-fifo for that
rewind-fifo mylist
start-loop


    read-fifo mylist key k value v status st


    if-true st not-equal GG_OKAY


        break-loop


    end-if


    @Again obtained key <<print-out k>> with value <<print-out v>>
end-loop
purge-fifo mylist

SEE ALSO¶

FIFO

delete-fifo new-fifo purge-fifo read-fifo rewind-fifo write-fifo See all documentation