FUNCTIONUnder review

FOpen

FOpen( cArq, [nModo], [xParam3], [lChangeCase] ) --> nRet

Opens an existing file and returns its handle.

FOpenAdvPL

01 · OVERVIEW

Overview

FOpen does not create missing files. nModo combines Fileio.ch access and sharing flags; this example chooses shared read-only access whereas the community source requests read/write. Handle zero is valid and -1 is failure. The page states lookup does not follow AdvPL Set Default/Set Path; lChangeCase matters for case-sensitive names. editorial-test.txt must exist in the test context; the fragment closes only its own handle. (TOTVS, n.d., ref. 1)

02 · SYNTAX

Syntax

FOpen( cArq, [nModo], [xParam3], [lChangeCase] ) --> nRet

Parameters

cArq

CharacterRequired

Filename with path when needed.

nModo

NumericOptional

Fileio.ch access + sharing.

xParam3

AnyOptional

Compatibility: Nil.

lChangeCase

LogicalOptional

Filename case handling according to build/configuration.

Return value

Handle >= 0; -1 on failure.

03 · PRACTICAL EXAMPLE

Commented example

#Include "Protheus.ch"
#Include "Fileio.ch"

User Function Ed388()
    Local nHandle := -1
    Local nError := 0

    // Pre-existing fictional file in the test context; shared reading.
    nHandle := FOpen("editorial-test.txt", FO_READ + FO_SHARED)
    If nHandle < 0
        nError := FError()
        ConOut(cValToChar(nError))
    Else
        ConOut("File opened for reading")
        If !FClose(nHandle)
            ConOut(cValToChar(FError()))
        EndIf
    EndIf
Return Nil

Expected result

Open message followed by closure, or a failure code. Under review: editorial example neither compiled nor run in Protheus. Check includes, release, RDD and context before testing.

BEST PRACTICES

Check path, permissions, platform and handle ownership. Close only handles obtained by this routine, including complete-application error handling.
Under review: editorial example neither compiled nor run in Protheus. Check includes, release, RDD and context before testing.