Jump to script label

  goto <label>

  :loop
  echo Hello world
  goto loop

  goto host_${hostname} || goto unknown

Jump to a script label. This command can be used only within an iPXE script.

It is logically impossible for this command to return successfully.

• inc
• isset
• iseq
• exit
• iPXE scripting guide
• List of all iPXE commands

If you are using goto to jump to a label when an operation succeeds, then you must also consider what would happen if the operation were to fail. For example:

  dhcp && goto dhcp_ok

If the dhcp command fails, then the script will immediately terminate, as described in the scripting guide. To avoid this problem, you can use the || operator:

  dhcp && goto dhcp_ok ||

As with all iPXE commands, any settings such as ${hostname} will be expanded. It is therefore possible to use a dynamically-generated label as the target for the goto command. For example, if the hostname provided by DHCP is thinclient1, then the command

  goto host_${hostname}

would jump to the label host_thinclient1.

When using dynamically-generated labels, it is generally a good idea to include a fallback label in case the dynamically-generated label does not exist. For example:

 #!ipxe
 
 dhcp
 goto host_${hostname} || goto unknown
 
 :host_thinclient1
 sanboot iscsi:192.168.0.1::::iqn.2010-04.org.ipxe:winxp
 
 :host_thinclient2
 sanboot iscsi:192.168.0.1::::iqn.2010-04.org.ipxe:win7
 
 :unknown
 echo Unknown host ${hostname}

You can construct simple loops using the inc and iseq commands.