# Referencing Launch Arguments in Scripts
## Description
Scripts run by FileWave can receive **Launch Arguments**. The arguments are supplied by FileWave and referenced by the script, but they are not written into the script body.
They may be supplied to any of the following:
- [Fileset Scripts](https://kb.filewave.com/books/filesets-payloads "Filesets / Payloads")
- [Custom Fields](https://kb.filewave.com/books/custom-fields/page/custom-fields "Custom Fields")
- Policy Blocker Scripts
Admins sometimes assume FileWave is limited to 9 launch arguments. It is not; the shell you use determines how you reference arguments 10 and higher.
## Information
Launch Arguments are positional parameters. They are referenced differently depending on the script type:
| | macOS/Linux | Windows Powershell | Windows Bat |
| First Argument | $1 | `$args[0]` | %1 |
| Second Argument | $2 | `$args[1]` | %2 |
| Third Argument | $3 | `$args[2]` | %3 |
You can add more arguments and reference each one by its position.
## Considerations
Shell behavior matters most when you reference the 10th argument or higher.
Although two solutions have been supplied, zsh is recommended to stay in line with Apple's policy: [https://support.apple.com/en-gb/HT208050](https://support.apple.com/en-gb/HT208050)
### bash and sh
The following bash example is intended to print the first 3 positional parameters, followed by the 10th and 11th.
**bash\_test.sh**
```shell
#!/bin/bash
echo $1
echo $2
echo $3
echo $10
echo $11
exit 0
```
If you pass only one argument, `1`, bash treats `$10` and `$11` differently than many admins expect:
**bash\_test.sh**
```shell
./bash_test.sh 1
1
10
11
```
The bash and sh shells treat `$10` as `${1}0`, `$11` as `${1}1`, and so on. In this example, they return the value of `$1` and append the extra character.
Additional references:
- [https://www.oreilly.com/library/view/bash-cookbook/0596526784/ch05s07.html](https://www.oreilly.com/library/view/bash-cookbook/0596526784/ch05s07.html)
- [https://www.oreilly.com/library/view/bash-cookbook/0596526784/ch05s04.html](https://www.oreilly.com/library/view/bash-cookbook/0596526784/ch05s04.html)
That output maps to:
| | Description | Output |
| $1 | Returns first argument | 1 |
| $2 | Returns second argument | 2 |
| $3 | Returns nothing, no third argument | |
| $10 | Returns first argument, followed by the '0' character | 10 |
| $11 | Returns first argument, followed by the '1' character | 11 |
For bash and sh, wrap two-digit positional parameters in braces so the script references the intended argument.
The corrected script uses braces for the 10th and 11th arguments.
**bash\_test.sh**
```shell
#!/bin/bash
echo $1
echo $2
echo $3
echo ${10}
echo ${11}
exit 0
```
Now when executed with 11 positional parameters, the expected output is displayed:
**bash\_test.sh**
```shell
./bash_test.sh var1a var2b var3c var4d var5e var6f var7g var8h var9i var10j var11k
var1a
var2b
var3c
var10j
var11k
```
### zsh
zsh handles this differently. With the same example in zsh:
**zsh\_test.sh**
```shell
#!/bin/zsh
echo $1
echo $2
echo $3
echo $10
echo ${11}
exit 0
```
Given the same 11 arguments, this would output:
**zsh\_test.sh**
```shell
./zsh_test.sh var1a var2b var3c var4d var5e var6f var7g var8h var9i var10j var11k
var1a
var2b
var3c
var10j
var11k
```
Unlike bash and sh, zsh treats `$10` as the 10th argument and `$11` as the 11th argument. zsh can use either format.
## Conclusion
If a script uses 10 or more launch arguments, check the shell before troubleshooting the FileWave side. In bash or sh, use `${10}`, `${11}`, and the same brace pattern for later arguments. In zsh, `$10` and `${10}` both refer to the 10th argument.
## Related Content
- [Custom Fields](https://kb.filewave.com/books/custom-fields/page/custom-fields "Custom Fields")
- [Filesets / Payloads](https://kb.filewave.com/books/filesets-payloads "Filesets / Payloads")