{"id":1433,"date":"2012-01-21T10:59:35","date_gmt":"2012-01-21T10:59:35","guid":{"rendered":"http:\/\/mccltd.net\/blog\/?page_id=1433"},"modified":"2012-01-21T17:33:30","modified_gmt":"2012-01-21T17:33:30","slug":"alias-and-script-to-start-dhcp-and-xen-vm","status":"publish","type":"page","link":"http:\/\/darenmatthews.com\/blog\/?page_id=1433","title":{"rendered":"Alias and Script to start DHCP and Xen VM"},"content":{"rendered":"

I wanted to create a bash script which started a dhcp server daemon and also started a Xen virtual machine. The script would be tiny and it would be executed using an alias, which I added to my bashrc.<\/p>\n

Here is the script:<\/p>\n

[root@shimla ~]# cat start.sh
\n#!\/bin\/bash
\n\/etc\/init.d\/dhcpd start
\ncd \/etc\/xen
\nxm create Elastix-PBX<\/p>\n

[root@shimla ~]#<\/p><\/blockquote>\n

Change permissions:<\/p>\n

[root@shimla ~]# chmod 777 start.sh
\n[root@shimla ~]#<\/p><\/blockquote>\n

Edit ~\/.bashrc to add an alias of “go” for the command “.\/start.sh” (see further below)<\/p>\n

alias go=\u2019.\/start.sh\u2019<\/p><\/blockquote>\n

Test (need to logout and back in to read bash profile again):<\/p>\n

[root@shimla ~]# go
\nStarting dhcpd: [ OK ]
\nUsing config file “.\/Elastix-PBX”.
\nStarted domain Elastix-PBX
\n[root@shimla ~]#<\/p><\/blockquote>\n

Linux startup files explained:<\/strong>
\nThese files contain the aliases and environmental variables made available to Bash running as a user shell and to all Bash scripts invoked after system initialization:<\/p>\n

\/etc\/profile<\/strong><\/em><\/p>\n

These are systemwide defaults, mostly setting the environment (all Bourne-type shells, not just Bash)<\/p>\n

\/etc\/bashrc<\/strong><\/em><\/p>\n

These are systemwide functions and aliases for Bash<\/p>\n

$HOME\/.bash_profile<\/strong><\/em><\/p>\n

These are user-specific Bash environmental default settings, found in each user’s home directory (the local counterpart to \/etc\/profile)<\/p>\n


\n$HOME\/.bashrc<\/strong><\/em><\/p>\n

These are user-specific Bash init file, found in each user’s home directory (the local counterpart to \/etc\/bashrc). Only interactive shells and user scripts read this file.<\/p>\n

Here are the contents of my startup files.<\/p>\n

[root@shimla init.d]# cat ~\/.bashrc
\n# .bashrc<\/p>\n

# User specific aliases and functions with “start.sh” alias (“go”) added:<\/p>\n

alias rm=’rm -i’
\nalias cp=’cp -i’
\nalias mv=’mv -i’
\nalias go=’.\/start.sh’<\/p>\n

# Source global definitions
\nif [ -f \/etc\/bashrc ]; then
\n. \/etc\/bashrc
\nfi
\n[root@shimla init.d]#<\/p><\/blockquote>\n

[root@shimla init.d]# cat ~\/.bash_profile
\n# .bash_profile<\/p>\n

# Get the aliases and functions
\nif [ -f ~\/.bashrc ]; then
\n. ~\/.bashrc
\nfi<\/p>\n

# User specific environment and startup programs<\/p>\n

PATH=$PATH:$HOME\/bin:\/usr\/sbin:\/sbin<\/p>\n

export PATH
\nunset USERNAME
\n[root@shimla init.d]#<\/p><\/blockquote>\n

Linux logout files:<\/p>\n

$HOME\/.bash_logout
\nThese are user-specific instruction file, found in each user’s home directory. Upon exit from a login (Bash) shell, the commands in this file execute.<\/p>\n","protected":false},"excerpt":{"rendered":"

I wanted to create a bash script which started a dhcp server daemon and also started a Xen virtual machine. The script would be tiny and it would be executed using an alias, which I added to my bashrc. Here is the script: [root@shimla ~]# cat start.sh #!\/bin\/bash \/etc\/init.d\/dhcpd start cd \/etc\/xen xm create Elastix-PBX […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":1395,"menu_order":0,"comment_status":"closed","ping_status":"open","template":"","meta":[],"_links":{"self":[{"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=\/wp\/v2\/pages\/1433"}],"collection":[{"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1433"}],"version-history":[{"count":4,"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=\/wp\/v2\/pages\/1433\/revisions"}],"predecessor-version":[{"id":1457,"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=\/wp\/v2\/pages\/1433\/revisions\/1457"}],"up":[{"embeddable":true,"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=\/wp\/v2\/pages\/1395"}],"wp:attachment":[{"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1433"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}