>How can I to identify if ZIP file is corrupted, through VFP?

Following what Rick has said, the parsing of the output may be elaborated as follow. This is what I use in the .NET Zip class I have built. But, this code is easily transportable to VFP:

                    ' If we have an output
                    If loProcessfile.cOutput.Length > 0 Then

                        ' Make it available in case the client needs it
                        cCommandLineFullOutput = loProcessfile.cOutput

                        ' Remove empty lines
                        cCommandLineFullOutput = oApp.StrTran(cCommandLineFullOutput, oApp.cCR + oApp.cCR, oApp.cCR)

                        ' End-of-central-directory signature not found.
                        If oApp.At("End-of-central-directory signature not found.", loProcessfile.cOutput) > 0 Then
                            cMessage = cEndOfCentralDirectorySignatureNotFound
                            Exit For
                        End If

                        ' End-of-central-directory signature not found.
                        If oApp.At(" CRC check failed", loProcessfile.cOutput) > 0 Then
                            cMessage = oApp.StrTran(cTheFileIsCorrupted, "##File##", cFile)
                            Exit For
                        End If

                        ' If we have a caution
                        lnLocation = oApp.At("CAUTION: ", UCase(cCommandLineFullOutput))

                        ' If we did not find it
                        If lnLocation = 0 Then

                            ' If we have an error
                            lnLocation = oApp.At("FATAL ERROR: ", UCase(cCommandLineFullOutput))

                            ' If we did not find it
                            If lnLocation = 0 Then

                                ' If we have an error
                                lnLocation = oApp.At("ERROR: ", UCase(cCommandLineFullOutput))

                            End If

                        End If

                        ' If we found one
                        If lnLocation > 0 Then
                            cMessage = Mid(cCommandLineFullOutput, lnLocation)

                            ' If we have a carriage return
                            lnLocation = oApp.At(oApp.cCR, cMessage)

                            ' If we found it
                            If lnLocation > 0 Then
                                cMessage = Mid(cMessage, 1, lnLocation - 1)
                            End If

                            Exit Try
                        End If

                    End If