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Melab
Asked: 2015-02-24 19:33:13 +0800 CST

How do I redirect the output of grub-mkpasswd-pbkdf2?

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I'm working in a command line-only environment, so I'm used to redirecting output to text files. In this instance, I need to set a password for GRUB2, but trying to use redirection with the corresponding utility makes it stop printing to the screen, so I am not presented with a way to enter my desired password. How do I solve this?

redirect

2 Answers

  1. Pipe the output to tee, which prints its input to stdout and optionally also to multiple files:

    grub-mkpasswd-pbkdf2 | tee out

    % grub-mkpasswd-pbkdf2 | tee out
Enter password: 
Reenter password: 
PBKDF2 hash of your password is grub.pbkdf2.sha512.10000.CF99115D7DE57D065ECA4420F829FACD1FEDDD1C08ACFDDEBBB6C2948DECECCA37DEBE4F0FB37FC8CAE385A1A440663225AFB2E79B4E69557F2F9BD13AB6E586.5D5AA1A70E60CF1C09AB6B9EF831996E3F60DF7B85ADE364C7E469DC88BAAE3D8DE0F1C2A5E60267170580564AF2A36DADA663DE2DF4407562A90FEAC7E78262
% cat out
Enter password: 
Reenter password: 
PBKDF2 hash of your password is grub.pbkdf2.sha512.10000.CF99115D7DE57D065ECA4420F829FACD1FEDDD1C08ACFDDEBBB6C2948DECECCA37DEBE4F0FB37FC8CAE385A1A440663225AFB2E79B4E69557F2F9BD13AB6E586.5D5AA1A70E60CF1C09AB6B9EF831996E3F60DF7B85ADE364C7E469DC88BAAE3D8DE0F1C2A5E60267170580564AF2A36DADA663DE2DF4407562A90FEAC7E78262
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  2. grub-mkpasswd-pbkdf2 writes the prompt and the encrypted password to stdout, so even if the prompt isn't visible, you can still type your password in, press Enter, type it again, and press Enter again:

    $ grub-mkpasswd-pbkdf2 > bar
$ cat bar
Enter password: 
Reenter password: 
PBKDF2 hash of your password is grub.pbkdf2.sha512.10000.40D06FD775735FA1E05AA2A732A588F79493CF7071718EFE99DEFFF06706421849716160D668D90D29139AD1A2537862DFCD6D1D172AEC7DF6552D948C472315.93544ED4795D377AB1C7FC40BA2079872F7AF19440931A7A0A71D7441C6EB563AE5438B60050F0573CF55FBD2FF0BF3ACE4811898794DD589E0BF4F184C9996C
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