Update a configuration file: Difference between revisions

This program is not tied to the task requested, but it can read and modify ANY configuration file. It is somewhat long, but includes functionality to modify or add variables and values to the configuration file, append remarks (#) to it, read and save values in an array (comma separated), toggle comment mode for variables in a configuration file, etc. It is even longer because is almost fully commented and in key procedures every parameter is explained. It includes a main program cycle to read the configuration file and modify its values.

' OPTION EXPLICIT ' For VB-DOS, PDS 7.1

' OPTION _EXPLICIT ' For QB64

' SUBs and FUNCTIONs

DECLARE SUB AppendCommentToConfFile (WhichFile AS STRING, WhichComment AS STRING, LeaveALine AS INTEGER)

DECLARE SUB setNValToVarArr (WhichVariable AS STRING, WhichIndex AS INTEGER, WhatValue AS DOUBLE)

DECLARE SUB setSValToVar (WhichVariable AS STRING, WhatValue AS STRING)

DECLARE SUB setSValToVarArr (WhichVariable AS STRING, WhichIndex AS INTEGER, WhatValue AS STRING)

DECLARE SUB doModifyArrValueFromConfFile (WhichFile AS STRING, WhichVariable AS STRING, WhichIndex AS INTEGER, WhatValue AS STRING, Separator AS STRING, ToComment AS INTEGER)

DECLARE SUB doModifyValueFromConfFile (WhichFile AS STRING, WhichVariable AS STRING, WhatValue AS STRING, Separator AS STRING, ToComment AS INTEGER)

DECLARE FUNCTION CreateConfFile% (WhichFile AS STRING)

DECLARE FUNCTION ErrorMessage$ (WhichError AS INTEGER)

DECLARE FUNCTION FileExists% (WhichFile AS STRING)

DECLARE FUNCTION FindVarPos% (WhichVariable AS STRING)

DECLARE FUNCTION FindVarPosArr% (WhichVariable AS STRING, WhichIndex AS INTEGER)

DECLARE FUNCTION getArrayVariable$ (WhichVariable AS STRING, WhichIndex AS INTEGER)

DECLARE FUNCTION getVariable$ (WhichVariable AS STRING)

DECLARE FUNCTION getVarType% (WhatValue AS STRING)

DECLARE FUNCTION GetDummyFile$ (WhichFile AS STRING)

DECLARE FUNCTION HowManyElementsInTheArray% (WhichVariable AS STRING)

DECLARE FUNCTION IsItAnArray% (WhichVariable AS STRING)

DECLARE FUNCTION IsItTheVariableImLookingFor% (TextToAnalyze AS STRING, WhichVariable AS STRING)

DECLARE FUNCTION NewValueForTheVariable$ (WhichVariable AS STRING, WhichIndex AS INTEGER, WhatValue AS STRING, Separator AS STRING)

DECLARE FUNCTION ReadConfFile% (NameOfConfFile AS STRING)

DECLARE FUNCTION YorN$ ()

DIM rVarValue() AS regVarValue, iErr AS INTEGER, i AS INTEGER, iHMV AS INTEGER

DIM iArrayElements AS INTEGER, iWhichElement AS INTEGER, iCommentStat AS INTEGER

DIM iAnArray AS INTEGER, iSave AS INTEGER

DIM otherfamily(1 TO 2) AS STRING

DIM sVar AS STRING, sVal AS STRING, sComment AS STRING

CONST ConfFileName = "config2.fil"

CONST False = 0, True = NOT False

' ------------------- Main Program ------------------------

DO

CLS

ERASE rVarValue

PRINT "This program reads a configuration file and shows the result."

PRINT

PRINT "Default file name: "; ConfFileName

PRINT

iErr = ReadConfFile(ConfFileName)

IF iErr = 0 THEN

iHMV = UBOUND(rVarValue)

PRINT "Variables found in file:"

FOR i = 1 TO iHMV

PRINT RTRIM$(rVarValue(i).VarName); " = "; RTRIM$(rVarValue(i).VarValue); " (";

SELECT CASE rVarValue(i).VarType

CASE 0: PRINT "Undefined";

CASE 1: PRINT "String";

CASE 2: PRINT "Integer";

CASE 3: PRINT "Real";

CASE 4: PRINT "Is a commented variable";

END SELECT

PRINT ")"

NEXT i

PRINT

INPUT "Type the variable name to modify (Blank=End)"; sVar

sVar = RTRIM$(LTRIM$(sVar))

IF LEN(sVar) > 0 THEN

i = FindVarPos%(sVar)

IF i > 0 THEN ' Variable found

iAnArray = IsItAnArray%(sVar)

IF iAnArray THEN

iArrayElements = HowManyElementsInTheArray%(sVar)

PRINT "This is an array of"; iArrayElements; " elements."

INPUT "Which one do you want to modify (Default=1)"; iWhichElement

IF iWhichElement = 0 THEN iWhichElement = 1

ELSE

iArrayElements = 1

iWhichElement = 1

END IF

PRINT "The current value of the variable is: "

IF iAnArray THEN

PRINT sVar; "("; iWhichElement; ") = "; RTRIM$(rVarValue(i + (iWhichElement - 1)).VarValue)

ELSE

PRINT sVar; " = "; RTRIM$(rVarValue(i + (iWhichElement - 1)).VarValue)

END IF

ELSE

PRINT "The variable was not found. It will be added."

END IF

PRINT

INPUT "Please, set the new value for the variable (Blank=Unmodified)"; sVal

sVal = RTRIM$(LTRIM$(sVal))

IF i > 0 THEN

IF rVarValue(i + (iWhichElement - 1)).VarType = 4 THEN

PRINT "Do you want to remove the comment status to the variable? (Y/N)"

iCommentStat = NOT (YorN = "Y")

iCommentStat = ABS(iCommentStat) ' Gets 0 (Toggle) or 1 (Leave unmodified)

iSave = (iCommentStat = 0)

ELSE

PRINT "Do you want to toggle the variable as a comment? (Y/N)"

iCommentStat = (YorN = "Y") ' Gets 0 (Uncommented) or -1 (Toggle as a Comment)

iSave = iCommentStat

END IF

END IF

' Now, update or add the variable to the conf file

IF i > 0 THEN

IF sVal = "" THEN

sVal = RTRIM$(rVarValue(i).VarValue)

END IF

ELSE

PRINT "The variable will be added to the configuration file."

PRINT "Do you want to add a remark for it? (Y/N)"

IF YorN$ = "Y" THEN

LINE INPUT "Please, write your remark: ", sComment

sComment = LTRIM$(RTRIM$(sComment))

IF sComment <> "" THEN

AppendCommentToConfFile ConfFileName, sComment, True

END IF

END IF

END IF

' Verifies if the variable will be modified, and applies the modification

IF sVal <> "" OR iSave THEN

IF iWhichElement > 1 THEN

setSValToVarArr sVar, iWhichElement, sVal

doModifyArrValueFromConfFile ConfFileName, sVar, iWhichElement, sVal, " ", iCommentStat

ELSE

setSValToVar sVar, sVal

doModifyValueFromConfFile ConfFileName, sVar, sVal, " ", iCommentStat

END IF

END IF

END IF

ELSE

PRINT ErrorMessage$(iErr)

END IF

PRINT

PRINT "Do you want to add or modify another variable? (Y/N)"

LOOP UNTIL YorN$ = "N"

' --------- End of Main Program -----------------------

PRINT

PRINT "End of program."

END

FileError:

iErr = ERR

RESUME NEXT

SUB AppendCommentToConfFile (WhichFile AS STRING, WhichComment AS STRING, LeaveALine AS INTEGER)

' Parameters:

' WhichFile: Name of the file where a comment will be appended.

' WhichComment: A comment. It is suggested to add a comment no larger than 75 characters.

' This procedure adds a # at the beginning of the string if there is no #

' sign on it in order to ensure it will be added as a comment.

' Var

DIM iFil AS INTEGER

iFil = FileExists%(WhichFile)

IF NOT iFil THEN

iFil = CreateConfFile%(WhichFile) ' Here, iFil is used as dummy to save memory

END IF

IF iFil THEN ' Everything is Ok

iFil = FREEFILE ' Now, iFil is used to be the ID of the file

WhichComment = LTRIM$(RTRIM$(WhichComment))

IF LEFT$(WhichComment, 1) <> "#" THEN ' Is it in comment format?

WhichComment = "# " + WhichComment

END IF

' Append the comment to the file

OPEN WhichFile FOR APPEND AS #iFil

IF LeaveALine THEN

PRINT #iFil, ""

END IF

PRINT #iFil, WhichComment

CLOSE #iFil

END IF

FUNCTION CreateConfFile% (WhichFile AS STRING)

' Var

DIM iFile AS INTEGER

ON ERROR GOTO FileError

iFile = FREEFILE

OPEN WhichFile FOR OUTPUT AS #iFile

CLOSE iFile

ON ERROR GOTO 0

CreateConfFile = FileExists%(WhichFile)

END FUNCTION

SUB doModifyValueFromConfFile (WhichFile AS STRING, WhichVariable AS STRING, WhatValue AS STRING, Separator AS STRING, ToComment AS INTEGER)

' To see details of parameters, please see doModifyArrValueFromConfFile

doModifyArrValueFromConfFile WhichFile, WhichVariable, 1, WhatValue, Separator, ToComment

END SUB

FUNCTION ErrorMessage$ (WhichError AS INTEGER)

' Var

DIM sError AS STRING

SELECT CASE WhichError

CASE 0: sError = "Everything went ok."

CASE 1: sError = "Configuration file doesn't exist."

CASE 2: sError = "There are no variables in the given file."

END SELECT

ErrorMessage$ = sError

END FUNCTION

END FUNCTION

FUNCTION FindVarPos% (WhichVariable AS STRING)

' Will find the position of the variable

FindVarPos% = FindVarPosArr%(WhichVariable, 1)

END FUNCTION

FUNCTION FindVarPosArr% (WhichVariable AS STRING, WhichIndex AS INTEGER)

' Var

DIM i AS INTEGER, iHMV AS INTEGER, iCount AS INTEGER, iPos AS INTEGER

DIM sVar AS STRING, sVal AS STRING, sWV AS STRING

SHARED rVarValue() AS regVarValue

' Looks for a variable name and returns its position

iHMV = UBOUND(rVarValue)

sWV = UCASE$(LTRIM$(RTRIM$(WhichVariable)))

sVal = ""

iCount = 0

DO

i = i + 1

sVar = UCASE$(RTRIM$(rVarValue(i).VarName))

IF sVar = sWV THEN

iCount = iCount + 1

IF iCount = WhichIndex THEN

iPos = i

END IF

END IF

LOOP UNTIL i >= iHMV OR iPos > 0

FindVarPosArr% = iPos

END FUNCTION

FUNCTION getArrayVariable$ (WhichVariable AS STRING, WhichIndex AS INTEGER)

' Var

DIM i AS INTEGER

DIM sVal AS STRING

SHARED rVarValue() AS regVarValue

i = FindVarPosArr%(WhichVariable, WhichIndex)

sVal = ""

IF i > 0 THEN

sVal = RTRIM$(rVarValue(i).VarValue)

END IF

' Found it or not, it will return the result.

' If the result is "" then it didn't found the requested variable.

getArrayVariable$ = sVal

END FUNCTION

FUNCTION getVariable$ (WhichVariable AS STRING)

' Var

DIM i AS INTEGER, iHMV AS INTEGER

DIM sVal AS STRING

' For a single variable, looks in the first (and only)

' element of the array that contains the name requested.

sVal = getArrayVariable$(WhichVariable, 1)

getVariable$ = sVal

END FUNCTION

FUNCTION getVarType% (WhatValue AS STRING)

' Var

DIM sValue AS STRING, dValue AS DOUBLE, iType AS INTEGER

sValue = RTRIM$(WhatValue)

iType = 0

IF LEN(sValue) > 0 THEN

IF ASC(LEFT$(sValue, 1)) < 48 OR ASC(LEFT$(sValue, 1)) > 57 THEN

iType = 1 ' String

ELSE

dValue = VAL(sValue)

IF CLNG(dValue) = dValue THEN

iType = 2 ' Integer

ELSE

iType = 3 ' Real

END IF

END IF

END IF

getVarType% = iType

END FUNCTION

FUNCTION HowManyElementsInTheArray% (WhichVariable AS STRING)

' Var

DIM i AS INTEGER, iHMV AS INTEGER, iCount AS INTEGER, iPos AS INTEGER, iQuit AS INTEGER

DIM sVar AS STRING, sVal AS STRING, sWV AS STRING

SHARED rVarValue() AS regVarValue

' Looks for a variable name and returns its value

iHMV = UBOUND(rVarValue)

sWV = UCASE$(LTRIM$(RTRIM$(WhichVariable)))

sVal = ""

' Look for all instances of WhichVariable in the

' list. This is because elements of an array will not alwasy

' be one after another, but alternate.

FOR i = 1 TO iHMV

sVar = UCASE$(RTRIM$(rVarValue(i).VarName))

IF sVar = sWV THEN

iCount = iCount + 1

END IF

NEXT i

HowManyElementsInTheArray = iCount

END FUNCTION

FUNCTION IsItAnArray% (WhichVariable AS STRING)

' Returns if a Variable is an Array

IsItAnArray% = (HowManyElementsInTheArray%(WhichVariable) > 1)

FUNCTION ReadConfFile% (NameOfConfFile AS STRING)

DIM iFile AS INTEGER, iType AS INTEGER, iVar AS INTEGER, iHMV AS INTEGER

DIM iVal AS INTEGER, iCurVar AS INTEGER, i AS INTEGER, iErr AS INTEGER

DIM dValue AS DOUBLE, iIsComment AS INTEGER

DIM sLine AS STRING, sVar AS STRING, sValue AS STRING

' This procedure reads a configuration file with variables

' and values separated by the equal sign (=) or a space.

' It needs the FileExists% function.

' Lines begining with # or blank will be ignored.

IF FileExists%(NameOfConfFile) THEN

iFile = FREEFILE

REDIM rVarValue(1 TO 10) AS regVarValue

OPEN NameOfConfFile FOR INPUT AS #iFile

WHILE NOT EOF(iFile)

LINE INPUT #iFile, sLine

sLine = RTRIM$(LTRIM$(sLine))

IF LEN(sLine) > 0 THEN ' Does it have any content?

IF LEFT$(sLine, 1) <> "#" THEN ' Is not a comment?

iIsComment = (LEFT$(sLine, 1) = ";")

IF iIsComment THEN ' It is a commented variable

sLine = LTRIM$(MID$(sLine, 2))

END IF

iVar = INSTR(sLine, "=") ' Is there an equal sign?

IF iVar = 0 THEN iVar = INSTR(sLine, " ") ' if not then is there a space?

GOSUB AddASpaceForAVariable

iCurVar = iHMV

IF iVar > 0 THEN ' Is a variable and a value

rVarValue(iHMV).VarName = LEFT$(sLine, iVar - 1)

ELSE ' Is just a variable name

rVarValue(iHMV).VarName = sLine

rVarValue(iHMV).VarValue = ""

END IF

IF iVar > 0 THEN ' Get the value(s)

sLine = LTRIM$(MID$(sLine, iVar + 1))

DO ' Look for commas

iVal = INSTR(sLine, ",")

IF iVal > 0 THEN ' There is a comma

rVarValue(iHMV).VarValue = RTRIM$(LEFT$(sLine, iVal - 1))

GOSUB AddASpaceForAVariable

rVarValue(iHMV).VarName = rVarValue(iHMV - 1).VarName ' Repeats the variable name

sLine = LTRIM$(MID$(sLine, iVal + 1))

END IF

LOOP UNTIL iVal = 0

rVarValue(iHMV).VarValue = sLine

END IF

' Determine the variable type of each variable found in this step

FOR i = iCurVar TO iHMV

IF iIsComment THEN

rVarValue(i).VarType = 4 ' Is a comment

ELSE

GOSUB DetermineVariableType

END IF

NEXT i

END IF

END IF

WEND

CLOSE iFile

IF iHMV > 0 THEN

REDIM PRESERVE rVarValue(1 TO iHMV) AS regVarValue

iErr = 0 ' Everything ran ok.

ELSE

REDIM rVarValue(1 TO 1) AS regVarValue

iErr = 2 ' No variables found in configuration file

ELSE

iErr = 1 ' File doesn't exist

END IF

ReadConfFile = iErr

EXIT FUNCTION

AddASpaceForAVariable:

iHMV = iHMV + 1

IF UBOUND(rVarValue) < iHMV THEN ' Are there space for a new one?

REDIM PRESERVE rVarValue(1 TO iHMV + 9) AS regVarValue

END IF

RETURN

DetermineVariableType:

sValue = RTRIM$(rVarValue(i).VarValue)

IF LEN(sValue) > 0 THEN

IF ASC(LEFT$(sValue, 1)) < 48 OR ASC(LEFT$(sValue, 1)) > 57 THEN

rVarValue(i).VarType = 1 ' String

ELSE

dValue = VAL(sValue)

IF CLNG(dValue) = dValue THEN

rVarValue(i).VarType = 2 ' Integer

ELSE

rVarValue(i).VarType = 3 ' Real

END IF

END IF

END IF

RETURN

SUB setNValToVar (WhichVariable AS STRING, WhatValue AS DOUBLE)

' Sets a numeric value to a variable

setNValToVarArr WhichVariable, 1, WhatValue

END SUB

SUB setNValToVarArr (WhichVariable AS STRING, WhichIndex AS INTEGER, WhatValue AS DOUBLE)

' Sets a numeric value to a variable array

DIM sVal AS STRING

sVal = FORMAT$(WhatValue)

setSValToVarArr WhichVariable, WhichIndex, sVal

END SUB

SUB setSValToVar (WhichVariable AS STRING, WhatValue AS STRING)

' Sets a string value to a variable

setSValToVarArr WhichVariable, 1, WhatValue

END SUB

SUB setSValToVarArr (WhichVariable AS STRING, WhichIndex AS INTEGER, WhatValue AS STRING)

' Sets a string value to a variable array

' Var

DIM i AS INTEGER

DIM sVar AS STRING

i = FindVarPosArr%(WhichVariable, WhichIndex)

IF i = 0 THEN ' Should add the variable

IF UBOUND(rVarValue) > 0 THEN

sVar = RTRIM$(rVarValue(1).VarName)

IF sVar <> "" THEN

i = UBOUND(rVarValue) + 1

REDIM PRESERVE rVarValue(1 TO i) AS regVarValue

ELSE

i = 1

ELSE

REDIM rVarValue(1 TO i) AS regVarValue

rVarValue(i).VarName = WhichVariable

END IF

' Sets the new value to the variable

rVarValue(i).VarValue = WhatValue

rVarValue(i).VarType = getVarType%(WhatValue)

END SUB

FUNCTION YorN$ ()

' Var

DIM sYorN AS STRING

DO

sYorN = UCASE$(INPUT$(1))

IF INSTR("YN", sYorN) = 0 THEN

BEEP

END IF

LOOP UNTIL sYorN = "Y" OR sYorN = "N"

YorN$ = sYorN

END FUNCTION

In the following example, the user can modify the variables, their comment status and add the NUMBEROFSTRAWBERRIES variable with the value of 64000. In this case, the user is modifying the value of the NUMBEROFBANANAS variable in the configuration file.

This program reads a configuration file and shows the result.

Default file name: config.fil

Variables found in file:

FAVOURITEFRUIT = banana (String)

NEEDSPEELING = (Undefined)

SEEDSREMOVED = (Is a commented variable)

NUMBEROFBANANAS = 48 (Integer)

Type the variable name to modify (Blank=End)? numberofbananas

The current value of the variable is:

NUMBEROFBANANAS = 48

Please, set the new value for the variable (Blank=Unmodified)? 1024

Do you want to toggle the variable as a comment? (Y/N)

Do you want to add or modify another variable? (Y/N)