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cmd:goto [2011/03/23 19:30] mcb30 |
cmd:goto [2013/08/01 14:21] (current) mcb30 |
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| ===== See also ===== | ===== See also ===== | ||
| + | * ''[[:cmd:inc]]'' | ||
| + | * ''[[:cmd:isset]]'' | ||
| + | * ''[[:cmd:iseq]]'' | ||
| * ''[[:cmd:exit]]'' | * ''[[:cmd:exit]]'' | ||
| * iPXE [[:scripting|scripting]] guide | * iPXE [[:scripting|scripting]] guide | ||
| Line 34: | Line 37: | ||
| ===== Notes ===== | ===== Notes ===== | ||
| + | |||
| + | 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 ''[[:cmd:dhcp]]'' command fails, then the script will immediately terminate, as described in the [[:scripting#error_handling|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 | 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 | ||
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| :unknown | :unknown | ||
| echo Unknown host ${hostname} | echo Unknown host ${hostname} | ||
| + | |||
| + | You can construct simple loops using the ''[[:cmd:inc]]'' and ''[[:cmd:iseq]]'' commands. | ||
