UNIX for Dummies Questions & Answers

I am 100% new to Unix and trying to learn.
This is my first time even touching a script in Unix.

We have the following variable script that I am trying to run....

Code:

##################################
###### variable test###
##################################
Hostname=`hostname`
export PS1='${Hostname}:${PWD}>'
OMNIHOME=/lcl/prd/apps/Tivoli/netcool/omnibus
export OMNIHOME
NCHOME=/lcl/prd/apps/Tivoli/netcool
export NCHOME
NETCOOL_LICENSE_FILE=27000@seville
export NETCOOL_LICENSE_FILE
JAVA_HOME=/usr/java
export JAVA_HOME
PATH=$PATH:$NCHOME/omnibus/bin
export PATH
LD_LIBRARY_PATH=$NCHOME/platform/solaris2/lib; export LD_LIBRARY_PATH
NC_RULES_HOME=$NCHOME/common/rules; export NC_RULES_HOME
stty erase ^H
EDITOR=vi

Now if I try to excute this by the following....
./logintest.sh

It just goes right back to a bash-3.00$ prompt and does nothing.

If I try it this way....

sh logintest.sh I get this....

logintest.sh: PS1=${Hostname}:${PWD}>: is not an identifier


Now if I do a more on this file and then do a highlight with a right click to place the commands directly in then it works just fine. Also the perms are set to 777.


Could anybody please tell me what I am doing wrong? I am really lost here.

Thanks in advance!

Consider adding your script to the .bashrc file so you do not have to source your script to make those changes happen to your envrionment

Code:

# two ways to source 
source myscript.sh
# or  (note the leading dot  - space )
.  myscript.h

So I guess I still do not understand though.... Why is the above not working for me when I execute the sh file?

Can something like this...
export PS1='${Hostname}:${PWD}>'

Only be used in a .profile in Unix?

ok.

when you write a script, then execute it, the script runs as a child process. Any changes you make to the environment (variables are part of the environment) are made to the child's envrionment. When the child exits at the end of the script, you revert back to the parent environment. All child changes are lost.

<dot space>script.sh - means runs this in the parent envrionment. This is called sourcing. bash supports a builtin function, source, which is the same as the dot thing.
When you source some script, environment changes are kept in the same process, the parent. .bashrc or .profile are run when you login - they are sourced.

Ok so what your saying is that this indeed running expect that after the run because its a child its going back to before the run so fast that it looks as if it never ran? I think I got that right.

No. Parent has memory with variables in it. Child inherits new copy of memory with identical memory. Child changes memory. Child exits. Child memory ceases to exist. Parent memory takes over again, but never, ever was changed. Parent cannot know about child changes.

It has nothing to do with going by fast.