[CentOS] Bash Script help...

[Rajagopal Swaminathan]

Jason Todd Slack-Moehrle <mailinglists at ...> writes:

> 
> Hi All,
> 
> I need to write a script that I will manually start (or a cron job in  
> future) but I need it to do a number of things in order one after  
> another.  How do i do that so everything gets dont as the steps depend  
> on each other.
> 
> Example:
> 
> cd /system_backups/
> 
> tar cvf apache-conf.tar /etc/httpd/conf/*
> gzip -v9 apache-conf.tar
> 
> tar cvf apache-data.tar /var/www/*
> gzip -v9 apache-data.tar
> 
> then last step...
> tar cvf <current_date>-system_backup.tar <all> the gzip files above
> gzip -v9 <current_date>-system_backup.tar
> 
> scp <current_date>-system_backup.tar.gz user at ...:/.
> etc...etc....
> 
> My questions:
> 1. How do I execute each statement and make sure subsequent statements  
> are not executed until the previous is done?

by using &&

example
cd /system_backups/ && \
  tar cvf apache-conf.tar /etc/httpd/conf/* && \
  gzip -v9 apache-conf.tar



> 2. How do I error check so if a step fails the script stops?

I am afraid I do not have enough knowledge to help you in the above question

> 
> 3. Since I run an SMTP Server on this box can I e-mail myself from  
> bash the nightly results?

Yes

> 
> 4. when I want to run the scp to send over the file to another machine  
> for safety, how can I have it know the password to the machine I am  
> scp'ing to?

You cant

You will have to ssh-keygen


Thanks and Regards

Rajagopal