I am very new to Linux, please bear with me. I've just installed CentOS7. I am trying to install hadoop. After creating a 'hadoop' user, the instructions I'm following say to run: ssh localhost (just to test it I'm guessing). That's when things go awry, and I am not able to continue with my installation.

My guess is a PATH has gotten mangled somewhere along the way.. perhaps? I did install Java 1.8, and some python libraries prior to this.

Can it be fixed, or reset?

Thanks in advance,
Koza

[hadoop@uk ~]$ ssh localhost
Last login: Sun Oct 25 23:35:44 2015
-bash: id: command not found
-bash: id: command not found
-bash: id: command not found
-bash: tty: command not found
-bash: ls: command not found
/usr/libexec/grepconf.sh: line 5: grep: command not found
-bash: tty: command not found
-bash: mktemp: command not found
-bash: $TMP: ambiguous redirect
-bash: rm: command not found
-bash: grep: command not found
bash: perl: command not found...
bash: grep: command not found...
bash: uname: command not found...

Yes, probably you messed up your path...

Could you run (or any other user file that you were asked to modify) and paste the result?

[hadoop@uk ~]$ /usr/bin/cat ~/.bash_profile
# .bash_profile

# Get the aliases and functions
if [ -f ~/.bashrc ]; then
. ~/.bashrc
fi

# User specific environment and startup programs

PATH=$PATH:$HOME/.local/bin:$HOME/bin:/bin:/usr/local/bin

export PATH

hmm... Can you (sorry I didn't also asked for this the first time -- I just thought it's a typo in your bash_profile)

[hadoop@uk ~]$ echo $PATH
/home/hadoop/perl5/bin:/usr/lib64/qt-3.3/bin:$PATH:/opt/jdk1.8.0_60/bin:/opt/jdk1.8.0_60/jre/bin:/usr/local/sbin:/usr/sbin:/home/hadoop/.local/bin:/home/hadoop/bin:/bin:/usr/local/bin

Ok... In your ~/.bashrc you probably have a line that starts with PATH= and contains values in simple quotes(')
Edit the file and simply remove those quotes or transform them in double quotes (")

You should be able to start a quick familiar editor with:

I don't see that. But I think I see what you are getting at. Is it the $PATH part in the PATH?

Here is my .bashrc. THere isn't much there:

# .bashrc

# Source global definitions
if [ -f /etc/bashrc ]; then
. /etc/bashrc
fi

# Uncomment the following line if you don't like systemctl's auto-paging feature:
# export SYSTEMD_PAGER=

# User specific aliases and functions

Yes.. That $PATH got there because bash did not expand it (one common reason being the use of single quotes)..
If it's not there then you mangled with your system setting... Search in /etc/bashrc and try to locate the problem..

P.S. If it's not obvious, you can get a functional temporary session by running .. But you still need to find and correct the actual problem..

1 members found this post helpful.

it was this, in the /etc/environment file. When I removed it, I no longer got the messages about missing commands when running ssh localhost.

There are no quotes though, single or double. Is this syntax incorrect?

export JAVA_HOME=/opt/jdk1.8.0_60

export JRE_HOME=/opt/jdk1.8.0_60/jre

export PATH=$PATH:/opt/jdk1.8.0_60/bin:/opt/jdk1.8.0_60/jre/bin

Thank you Smokey_justme.

Really appreciate the help

I marked this as solved. This is my first time on this forum, is there anything else I need to do? award points?

It's weird... That should have been a problem.. But at least it's solved for now... About the forum, it's ok.. Just marking a topic as solved to be easily discovered that it contains a solution is sufficient...

To expand on this: Quotation marks are only needed if you want to remove the special meaning of special characters, like * (asterisk), ? (question mark), $ (dollar sign) and so on. There are no special characters in the strings above.

You can use single quotation marks, which quote everything except single quotation marks.
Or you can use double quotation marks, which don't quote everything. Notably, strings that start with a $ (dollar sign) will be interpreted as shell variables inside (and of course outside) double quotes.