Passing folder path from R to Powershell

Question

I have this Powershell script that I need to run in R. So, in Rstudio's Terminal I paste this escaped Powershell script:

system('powershell -command "
$folder = \'C:\\Users\\User\\Documents\\Folder Name\\\'
$userAgent = \'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:7.0.1) Gecko/20100101 Firefox/7.0.1\'
$web = New-Object System.Net.WebClient
$web.Headers.Add(\'user-agent\', $userAgent)
$input = \'C:\\Users\\Administrator\\User\\Another Folder Name\\data.csv\'
$delimit = \' \'

Get-Content $input |
    Foreach-Object { 
        $line = $_.split($delimit);
        $destination_file = ([io.path]::getfilename($line[1]))
        \'[\' + $destination_file  + \']\' + \'Downloading \' + $line[0]
        try {
            $target = join-path $folder $destination_file
            $web.DownloadFile($line[0], $target)
        } catch {
            $_.Exception.Message + \': \' + $destination_file
            add-content (join-path $folder (\'downloader\' + \'.log\')) (\'[\' + $destination_file + \'] \' + $_.Exception.Message)
            add-content (join-path $folder (\'downloader\' + \'.retry\')) ($line -join \' \')
        }
    }
"')

And it all works as expected.

Now, I am trying to define the $folder and $Input from the Powershell script in R, like so:

Rpath <- "C:/Users/User/Documents/Folder Name/"
var <- system('powershell -command "
$folder = \'Rpath\'
$userAgent = \'Mozilla/5.0 ...

I need help figuring out how to pass this Rpath from R into the escaped Powershell script.

Any help would be greatly appreciated

Thanks @I_O for your help I followed your advise and entered in Rstudio:

folder = "'C:\Users\User\Documents\Folder Name\'"
input = "'C:\Users\Administrator\User\Another Folder Name\data.csv'"
text = "
$folder = %s
$userAgent = \'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:7.0.1) Gecko/20100101 Firefox/7.0.1\'
$web = New-Object System.Net.WebClient
$web.Headers.Add(\'user-agent\', $userAgent)
$input = %s
$delimit = \' \'

Get-Content $input |
    Foreach-Object { 
        $line = $_.split($delimit);
        $destination_file = ([io.path]::getfilename($line[1]))
        \'[\' + $destination_file  + \']\' + \'Downloading \' + $line[0]
        try {
            $target = join-path $folder $destination_file
            $web.DownloadFile($line[0], $target)
        } catch {
            $_.Exception.Message + \': \' + $destination_file
            add-content (join-path $folder (\'downloader\' + \'.log\')) (\'[\' + $destination_file + \'] \' + $_.Exception.Message)
            add-content (join-path $folder (\'downloader\' + \'.retry\')) ($line -join \' \')
        }
    }
"
sprintf(text, folder, input)

which returned:

[1] "\n$folder = 'C:\\Users\\Administrator\\Documents\\Trading\\ETF Arbitrage\\Market Data\\Borrow Fees\\ChartExchange\\PowerShell\\'\n$userAgent = 'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:7.0.1) Gecko/20100101 Firefox/7.0.1'\n$web = New-Object System.Net.WebClient\n$web.Headers.Add('user-agent', $userAgent)\n$input = 'C:\\Users\\Administrator\\Documents\\Trading\\ETF Arbitrage\\Market Data\\Borrow Fees\\ChartExchange\\data.csv'\n$delimit = ' '\n\nGet-Content $input |\n    Foreach-Object { \n        $line = $_.split($delimit);\n        $destination_file = ([io.path]::getfilename($line[1]))\n        '[' + $destination_file  + ']' + 'Downloading ' + $line[0]\n        try {\n            $target = join-path $folder $destination_file\n            $web.DownloadFile($line[0], $target)\n        } catch {\n            $_.Exception.Message + ': ' + $destination_file\n            add-content (join-path $folder ('downloader' + '.log')) ('[' + $destination_file + '] ' + $_.Exception.Message)\n            add-content (join-path $folder ('downloader' + '.retry')) ($line -join ' ')\n        }\n    }\n"

Sorry I am new at this. I have several follow up questions:

folder and input look the same in this result, as in the intended string, with 2 \\ as separators. However it gave an Error: '\U' used without hex digits in character string starting ""'C:\U"
All the \' turned into just '. If I change them to \\', they will return as \\' in the returned string, not the expected \'
There are all these \n now added
Finally, I tried system('powershell -command sprintf(text, folder, input)') to execute the Powershell script in R, but did not work.

About the first 3 questions, I don't know which ones do matter and which ones don't, if any. The 4th, not sure if that is the way.

Any further help would be most appreciated

Does this answer your question? [Is there a string formatting operator in R similar to Python's %?](https://stackoverflow.com/questions/46085274/is-there-a-string-formatting-operator-in-r-similar-to-pythons) — JosefZ, May 08 '23 at 20:43

score 0 · Answer 1 · answered May 08 '23 at 06:05

string substitution with sprintf might be handy:

folder = "\\path"
file = "\\door"
text = "the long and winding %s that leads to your %s"

sprintf(text, folder, file)
## [1] "the long and winding \\path that leads to your \\door"

Note that the s in %s is not a placeholder name but indicates that a string will be supplied. Accordingly, the arguments to sprintf must be arranged in the order of their intended appearance.

Passing folder path from R to Powershell

1 Answers1