The functions outlined below are written in VB.net but it should be possible to modify them for other computer languages.
This may need minor adjustments if you use special compiler options (Option Strict) because I have tried to simplify the code for ease of understanding

' convert a line read from a CSV file to a list of fields
Private Function readCSV(linein As String) As List(Of String)
    Dim ret As List(Of String) = New List(Of String)
    Dim c As Char = " "
    Dim temp As String = ""
    ret.Clear()
    If Not linein.Contains("""") Then
        ret.AddRange(linein.Split(","))
        Return ret
    End If
    Dim quoted As Boolean = False
    linein &= "," ' ensures lat field is correctly processed
    For i As Integer = 1 To Len(linein)
        c = Mid(linein, i, 1)
        If ((Not quoted) And (c = ",")) Then
            ret.Add(temp)
            temp = ""
        Else
            temp &= c
        End If
    Next
    For i As Integer = 0 To ret.Count - 1
        temp = ret.Item(i)
        temp = Trim(temp)
        ' remove leading and trailing quote
        If ((Mid(temp, 1, 1) = """") And (Mid(temp, Len(ret.Item(i)), 1) = """")) Then
             temp = Mid(temp, 2, Len(temp) - 1)
             temp = Mid(temp, 1, Len(temp) - 1)
        End If
        ' replace "" with "
        temp.Replace("""", "")
        ret.Item(i) = temp
    Next
    Return ret
End Function

' convert a list of fields into a string that could be written to a csv file
Private Function writeCSV(parts As List(Of String)) As String
    Dim ret As String = ""
    Dim temp As String
    For i As Integer = 0 To parts.Count - 1
        temp = parts.Item(i)
        If temp.Contains("""") Then
            temp = temp.Replace("""", """""")
        End If
        If ((temp.Contains("""")) Or (temp.Contains(",")) Or (temp.Contains("'")) Or (temp <> Trim(temp))) Then
            temp = """" & temp & """"
        End If
        If i <> 0 Then ret &= ","
        ret &= temp
    Next
    Return ret
End Function

' Remove any accents from a string
Public Function RemoveAccents(txt As String) As String
    Dim normalizedString As String = txt.Normalize(System.Text.NormalizationForm.FormD)
    Dim ret As String = ""
    Dim c As Char
    Dim stringBuilder As System.Text.StringBuilder = New System.Text.StringBuilder
    For i = 0 To normalizedString.Length - 1
        c = normalizedString(i)
        If System.Globalization.CharUnicodeInfo.GetUnicodeCategory(c) <> System.Globalization.UnicodeCategory.NonSpacingMark Then
            stringBuilder.Append(c)
        End If
    Next
    Return stringBuilder.ToString()
End Function

' Replacement for Left$( ... ) which was present inearly versions of Basic
Public Function lleft(text As String, length As Integer) As String
    if length >= Len(text) Then Return text
    if length = 0 Then Return ""
    Return Mid(text, 1, length)
End Function

' Replacement for Right$( ... ) which was present inearly versions of Basic
Public Function rright(text As String, length As Integer) As String
    If length < 1 Then Return ""
    If length >= Len(text) Then Return text
    Return Mid(text, Len(text) - length + 1, length)
End Function