github.com/hashicorp/packer@v1.14.3/website/content/docs/templates/hcl_templates/functions/index.mdx (about)

     1  ---
     2  page_title: Built-in functions reference overview
     3  description: |-
     4    Functions built into HCL language can transform and combine values. Learn about using built-in functions in your Packer templates. 
     5  ---
     6  
     7  # Built-in functions overview
     8  
     9  This topic provides an overview of the built-in HashiCorp configuration language (HCL) functions you can use in your Packer templates. 
    10  
    11  ## Functions syntax
    12  
    13  You can use functions in Packer templates to transform and combine values. The 
    14  syntax for function calls is a function name followed by comma-separated
    15  arguments in parentheses:
    16  
    17  ```hcl
    18  max(5, 12, 9)
    19  ```
    20  
    21  For information on invoking functions in string literals, refer to the
    22  [string literals reference](/packer/docs/templates/hcl_templates/expressions#string-literals) section.
    23  
    24  HCL does not support user-defined functions. You can only call
    25  the functions built into the language.