Need to run sudo for a normal user script sub-function

[lsatenstein]

I have a script with multiple functions
vis
function definition1() ...
function definition2() ...
function definition3()...

#When I invoke the script I would like to have

definition1
sudo definition2
definition 3
exit 0

From what I have read, because I want definition2 to be invoked via sudo, I should make it a stand alone script. But I really would like it to remain in this script because of defined variables and functions.

Is it possible for a standard (non root owned script) to do some work with root's libraries if the script is run by an administrator ?

[bgstack15]

Sudo executes other executables with root privileges. Unfortunately you cannot call a function defined by the shell (bash) because it's just a part of bash. So what you can do is go modify definition2(), find all the executables that are run, and insert the sudo statement in front of them.

[lsatenstein]

In a related topic,

If I do a sudo su or sudo command, during the time the script or user is in root, does the $LOGNAME remain that of the user or it changes to that of root.

I have a sudo alias which is

alias sudo='sudo ' #one space character after the o in the substitution.

With Gnome/Fedora, $LOGNAME is invariant.
With SUSE Tumbleweed $LOGNAME takes on the value root during sudo execution

I did solve my problem with using $SUDO_USER in place of LOGNAME, while executing as root.

[ocratato]

The problem with using an environment variable is that they can be set to almost anything. Hence it is not a reliable way of determining the user.
A safer solution would be the logname command.

[lsatenstein]

The problem with using an environment variable is that they can be set to almost anything. Hence it is not a reliable way of determining the user.
A safer solution would be the logname command.

LOGNAME is not consistent vs SUSE and FEDORA

[ocratato]

LOGNAME is not consistent vs SUSE and FEDORA

Yes, you said that before.
What I am suggesting is that $LOGNAME is not a safe way to determine the user's identity since they might have done
export LOGNAME=fred
before running your script.

A safer way is to use the logname command. It should also be independent of the distribution and sudo.

[lsatenstein]

Hi Ocratato

Thanks for the idea about using th export. Rather than logname, I could export a variable containing my user id "$euid" or $LOGNAME to a new variable.
If you use modify sudo rules via sudo visudo
and uncomment the line

%wheel ALL=(ALL) NOPASSWD: ALL

This allowed me to run

#/bin/bash
function1( ){..)
function2( ){..)
function3( ){..)
function4( ){...}

if [ $euid ==0 ];
then
 function3  #needs root
 else
 function1
 function2
 sudo $0    #call myself as root.
 function4
fi
 exit 0
#......................

Fortunately RedHat and SUSE distributions allow a user to omit entering the pasword via that NOPASSWD keyword