NSIS FileRead conditional override

Question

I should please need your help as I am not a programmer (please have mercy with me). I should need to add in an existing NSIS script a function that does the following:

Checks the presence of a value called 169.254.1.1 into a INI file named myfile.ini and placed in

c:\mydirectory

Should it find this value into myfile.ini it should not do anything else (i.e. let the script do the next steps).

Should it NOT find this value into myfile.ini it should override the file

with another one by silently copying it from c:\dummyfile\myfile.ini

and then let the script do the next steps.

I do not know how to tell NSIS to do this, may I please ask for your help?

Thanks in advance for your expertise.

Meleena.

Answer 1

If your file is an actual .INI file with [sections] then you can just use the INI functions:

Section "Prepare INI example"
InitPluginsDir
WriteIniStr "$PluginsDir\MyFile.ini" ServerInfo ServerAddress "169.254.1.1"
WriteIniStr "$PluginsDir\Dummy.ini" ServerInfo ServerAddress "127.0.0.1"
SectionEnd

!include LogicLib.nsh
Section
ReadIniStr $0 "$PluginsDir\MyFile.ini" ServerInfo ServerAddress
ReadIniStr $1 "$PluginsDir\MyFile.ini" ServerInfo ServerAddressBck
${If} $0 != "169.254.1.1"
${AndIf} $1 != "169.254.1.1"
    CopyFiles /SILENT /FILESONLY "$PluginsDir\Dummy.ini" "$PluginsDir\MyFile.ini"
${EndIf}
SectionEnd

If you don't have a real .INI file, just a file with name=value pairs then you have to parse manually:

Section "Prepare fake INI example"
InitPluginsDir
FileOpen $0 "$PluginsDir\MyFile.ini" w
FileWrite $0 'Foo$\r$\n'
FileWrite $0 'Bar$\r$\n'
FileWrite $0 'ServerAddress=169.254.1.1$\r$\n'
FileWrite $0 'Baz$\r$\n'
FileClose $0
WriteIniStr "$PluginsDir\Dummy.ini" ServerInfo ServerAddress "127.0.0.1"
SectionEnd

!include LogicLib.nsh

Function TrimTrailingNewlinesAndSpaces
Exch $1
Push $2
again:
    StrCpy $2 $1 "" -1
    StrCmp $2 " " +3
    StrCmp $2 "$\r" +2
    StrCmp $2 "$\n" +1 +3
    StrCpy $1 $1 -1
    Goto again
Pop $2
Exch $1
FunctionEnd

Section
StrCpy $2 "" ; Have not found the magic line
ClearErrors
FileOpen $0 "$PluginsDir\MyFile.ini" r
loop:
    FileRead $0 $1
    IfErrors done
    Push $1
    Call TrimTrailingNewlinesAndSpaces
    Pop $1
    ${If} $1 == "ServerAddress=169.254.1.1"
    ${OrIf} $1 == "ServerAddressBck=169.254.1.1"
        StrCpy $2 1
    ${Else}
        Goto loop
    ${EndIf}
done:
FileClose $0
${If} $2 = 0
    CopyFiles /SILENT /FILESONLY "$PluginsDir\Dummy.ini" "$PluginsDir\MyFile.ini"
${EndIf}
SectionEnd