Explaining behaviour of sudo bash "$0" "$@"; Post: 303025410

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Top Forums Shell Programming and Scripting Explaining behaviour of sudo bash "$0" "$@"; Post 303025410 by bakunin on Friday 2nd of November 2018 12:06:19 AM

11-02-2018

Registered User

Quote:

Originally Posted by boqsc

Code:

if [ $EUID != 0 ]; then
    sudo bash "$0" "$@";
    exit "$?";
 fi

But the strange thing happens when I move this line outside the IF statement:

sudo bash "$0" "$@"; stops the code from running and only blinking dot stays with no progress further.

Not seeing from here what "$0" (the running programs name) and "$@" (a list of all comand line arguments to the running program) contains or any other parts of the environment you execute the snippet above in i can only speculate. The variable "EUID" is perhaps holding the "effective user ID", so the above reads: if you're not root already issue "sudo ...", which makes sense, because you need sudo to switch to root only if you aren't already root.

So my first guesses would be: either
- you try to use sudo as root and you have some sudo rule in place (or missing) that prevents correct execcution of whatever you try to execute, or
- your environment (especially "$0" and "$@" do not contain what you expect them to contain, maybe because of a switched context: switching to another user may cause settings to change, etc.) or
- There might be a reason for the following exit-statement. Leaving it out may prevent ending of the execution.

But to debug your script i'd have to see it and probably know a bit about your surroundings (OS, shell, version, ....) to do so. As long as you don't provide that you will be on your own.

I hope this helps.

bakunin

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gksu

GKSU(1) 							   User Commands							   GKSU(1)

NAME

       gksu - GTK+ frontend for su and sudo

SYNOPSIS

       gksu

       gksu [-u <user>] [options] <command>

       gksudo [-u <user>] [options] <command>

DESCRIPTION

       This manual page documents briefly gksu and gksudo

       gksu  is  a frontend to su and gksudo is a frontend to sudo.  Their primary purpose is to run graphical commands that need root without the
       need to run an X terminal emulator and using su directly.

       Notice that all the magic is done by the underlying library, libgksu. Also notice that the library will decide if it should use su or  sudo
       as  backend  using the /apps/gksu/sudo-mode gconf key, if you call the gksu command. You can force the backend by using the gksudo command,
       or by using the --sudo-mode and --su-mode options.

       If no command is given, the gksu program will display a small window that allows you to type in a command to be run,  and  to  select  what
       user the program should be run as. The other options are disregarded, right now, in this mode.

OPTIONS

       --debug, -d

	      Print information on the screen that might be useful for diagnosing and/or solving problems.

       --user <user>, -u <user>

	      Call <command> as the specified user.

       --disable-grab, -g

	      Disable the "locking" of the keyboard, mouse, and focus done by the program when asking for password.

       --prompt, -P

	      Ask the user if they want to have their keyboard and mouse grabbed before doing so.

       --preserve-env, -k

	      Preserve the current environments, does not set $HOME nor $PATH, for example.

       --login, -l

	      Make  this  a login shell. Beware this may cause problems with the Xauthority magic. Run xhost to allow the target user to open win-
	      dows on your display!

       --description <description|file>, -D <description|file>

	      Provide a descriptive name for the command to be used in the default message, making it nicer.  You can also  provide  the  absolute
	      path for a .desktop file. The Name key for will be used in this case.

       --message <message>, -m <message>

	      Replace  the  standard message shown to ask for password for the argument passed to the option.  Only use this if --description does
	      not suffice.

       --print-pass, -p

	      Ask gksu to print the password to stdout, just like ssh-askpass. Useful to use in scripts with programs that  accept  receiving  the
	      password on stdin.

       --su-mode, -w

	      Force gksu to use su(1) as its backend for running the programs.

       --sudo-mode, -S

	      Force gksu to use sudo(1) as its backend for running the programs.

SEE ALSO

       su(1), sudo(1)

gksu version 2.0.x						    August 2006 							   GKSU(1)