How does one execute the windows runas command from inside cygwin

Question

If I try to use the Windows runas command from inside Cygwin the Enter password line prints to standard out but it doesn't wait for me to type my password into System.in

Is there a way around this?

I don't need to execute the Windows shell as admin, I need to execute as a specific account with different privileges to my own. — James Robinson, Sep 16 '13 at 09:13
Then, can't you runas the cygwin shell as that specific account? — anishsane, Sep 16 '13 at 09:29
How should i pass the specific user with `cygstart --action=runas`? Is there really no solution for this? I need to start a script inside a existing cygwin shell that is executed as a different (specific) user. — realtime, Feb 12 '14 at 13:37
"Runas [...] likely [...] doesn't understand Cygwin's ptys": http://cygwin.1069669.n5.nabble.com/Runas-command-in-cygwin-td102990.html — ManuelAtWork, Jul 11 '18 at 08:56

score 4 · Accepted Answer · answered Dec 30 '16 at 01:30

I figured I could use 2 nested Command Prompt window pop-ups to run a password-changing script,

cygstart cmd /c "runas /user:DOMAIN\\USER \"powershell %cd%\\changepw.ps1\" & pause"

The changepw.ps1 script follows,

# http://serverfault.com/questions/570476/how-can-a-standard-windows-user-change-their-password-from-the-command-line
# cygstart cmd /c "runas /user:DOMAIN\\USER \"powershell %cd%\\changepw.ps1\" & pause"

param (
    [string]$oldPassword = $( Read-Host "Old password"),
    [string]$newPassword = $( Read-Host "New password")
)

$ADSystemInfo = New-Object -ComObject ADSystemInfo
$type = $ADSystemInfo.GetType()
$user = [ADSI] "LDAP://$($type.InvokeMember('UserName', 'GetProperty', $null, $ADSystemInfo, $null))"
try {
    $user.ChangePassword($oldPassword, $newPassword)
} catch [Exception] {
    # echo $_.Exception.GetType().FullName, $_.Exception.Message
    echo $_.Exception | format-list -force
}
write-host "Press any key to continue..."
[void][System.Console]::ReadKey($true)

score 1 · Answer 2 · answered Jul 11 '18 at 09:18

Instead of starting a "Cygwin Terminal", you can start a "Cygwin Console". You can do this by executing

c:\cygwin\bin\bash.exe --Login

Then, you should be able to run native Windows commands like runas.

(However, you lose some POSIX compatibility, because the shell will run in a Windows console window and not inside a MinTTY terminal.)

How does one execute the windows runas command from inside cygwin

2 Answers2