The following table provides examples showing how the command rewrite functionality provided on the Modify Command page can be used with positional parameters to replace the submitted command and parameters. The examples use the echo command as the rewritten command to display the selected parameters on the screen.
Table 6-1 Command Rewrite Examples
|
Function |
Rewrite |
Submitted Command |
Executed Command |
|---|---|---|---|
|
Insert all arguments ($0 is not displayed) |
echo $* |
ls passwd shadow fstab |
echo passwd shadow fstab |
|
Insert argument ’r;n’ |
echo $3 |
ls passwd shadow fstab |
echo fstab |
|
Insert all but argument 'n' ($0 is not displayed) |
echo ${^2} |
ls passwd shadow fstab |
echo passwd fstab |
|
Insert arguments from 'n' to end |
echo ${2-} |
ls passwd shadow fstab |
echo shadow fstab |
|
Insert arguments from 0 to 'n' |
echo ${-2} |
ls passwd shadow fstab |
echo ls passwd shadow |
|
Insert arguments from 'm' to 'n' |
echo ${1-2} |
ls passwd shadow fstab |
echo passwd shadow |
|
Insert the total number of arguments |
echo $# |
ls passwd shadow fstab |
echo 3 |
|
Insert contents of argument $# |
echo ${$#} |
ls passwd shadow fstab |
echo fstab |
In this example, the administrator usually does a backup of the system by using the following command:
ufsdump -0f /dev/rmt/0 /usr
Assume that new tape drive is installed on the host, and it must be used for the backup. In addition, the administrator must make sure that it is working correctly by using the -v flag to verify the tape.
You can ensure that the administrator doesn’t need to remember the changes by using the Rewrite field to create a command definition for the original command:
$0 -v $1 /dev/rmt/1 ${$#}
When the administrator enters the original command, the following command runs instead:
ufsdump -v -0f /dev/rmt/1 /usr