ProvideX V8.20 > Language Reference > 8. Special Files and Devices

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then insert the new one. The functions IND( ), p.455, KEF( ), p.464, KEL( ), p.465,

KEN( ), p.466, KEP( ), p.467, KEY( ), p.468, and RNO( ), p.512 can be used with

memory-queue files.

Format 2: Create Memory-Resident Multi-Key File

OPEN (chan[,fileopt])"*MEMORY* [;KEYDEF=key_def$ ]"

Use this format to create a memory-resident multi-key file similar to regular Keyed

files. I/O directives and functions supported by Keyed files are also supported by

this type of memory file. Due to the way this format is processed, performance is

generally better than using Format #1 with key access.

Files are limited to 2GB in size. The current size, or amount of memory being used

can be determined by querying NUM(FIN(chan,"FILELENGTH")) or

DEC($00$+MID(FIN(chan),1,4)). Extended records are supported by

indicating a record size in excess of 31,000 byte; e.g., BSZ=32000 (the BSZ= value, if

specified, must be a positive value).

Note: The ability to access a memory file in a mixed mode (by KEY= and/or IND=) is

not supported.

See Also

DIRECT Directive, p.88

KEYED Directive, p.165

Examples

The following example illustrates how to open and use *MEMORY* using Format 1:

00010

mmf=hfn

00020

open (mmf)"*memory*"

00030

print 'CS'

00040

input "Name (Press F4 to end):",name$

00050

if ctl=4 then goto 0100

00060

input "Address:",addr$

00070

input "Position:",pos$

00080

write (mmf,key=name$)iol=mmfLst

00090

goto 0030

00100

print 'CS'

00110

select iol=mmfLst from mmf begin "" end "z"

00120

print "Name:",name$

00130

print "Address:",addr$

00140

print "Position:",pos$

00150

print "----------"

00160

next record

00170

end

00180

mmfLst: iolist name$,addr$,pos$