Which files are read ?

Direct connection to a user

[user1@aixb007] /home/user1> set | grep PROF
PROFILE1=etc_environment
PROFILE2=etc_profile
PROFILE3=dot_profile_user1

Using su from root:

[user1@aixb007] /home/user1> set | grep PROF
PROFILE1=etc_environment
PROFILE2=etc_profile
PROFILE3=dot_profile_user1

Using crontab of the user1:

[user1@aixb007] /home/user1> cat crontab.txt
PROFILE1=etc_environment

Using sudo with Defaults:oracle !env_reset

[oracle@aixb007] /home/oracle> sudo su user1
[oracle@aixb007] /home/oracle> whoami
user1
[oracle@aixb007] /home/oracle> set | grep PROF
PROFILE1=etc_environment
PROFILE2=etc_profile
PROFILE4=dot_profile_oracle


[oracle@aixb007] /home/oracle> sudo su - user1
[user1@aixb007] /home/user1> whoami
user1
[user1@aixb007] /home/user1> set | grep PROF
PROFILE1=etc_environment
PROFILE2=etc_profile
PROFILE3=dot_profile_user1

Using sudo with Defaults:oracle env_reset

[oracle@aixb007] /home/oracle> sudo su user1
[oracle@aixb007] /home/oracle> whoami
user1
[oracle@aixb007] /home/oracle> set | grep PROF


[oracle@aixb007] /home/oracle> sudo su - user1
[user1@aixb007] /home/user1> whoami
user1
[user1@aixb007] /home/user1> set | grep PROF
PROFILE1=etc_environment
PROFILE2=etc_profile
PROFILE3=dot_profile_user1

login as root in ksh(93) and change to bash

[root@aixb007] /root> set | grep PROF
PROFILE1=etc_environment
PROFILE2=etc_profile
PROFILE5=dot_profile_root
[root@aixb007] /root> bash
[root@aixb007] /root> set | grep PROF
PROFILE1=etc_environment
PROFILE2=etc_profile
PROFILE5=dot_profile_root
PROFILE7=dot_bashrc_root

BASH on AIX doesn't use /etc/*bash*, nor ~/.bash_profile, the only file specific is .bashrc