| Task | Recommended Tool | |------|------------------| | Local development | Apache with SSI + error logging | | Syntax highlighting | VS Code + “SSI” or “Apache Conf” extensions | | Validate includes | Check server logs for “SSI missing file” | | Preview final output | Use “View Source” in browser after serving via localhost |

| Command | What it does | Example | | :--- | :--- | :--- | | #include | Inserts the contents of another file. | <!--#include virtual="/header.html" --> | | #echo | Outputs a variable (date, referrer, etc.). | <!--#echo var="LAST_MODIFIED" --> | | #exec | Runs a shell command or CGI script. | <!--#exec cmd="ls /logs" --> | | #if / #elif / #endif | Conditional logic. | Show one banner to Chrome, another to Firefox. | | #config | Formats date/time or error messages. | <!--#config timefmt="%B %d, %Y" --> |

Why would you use .shtml in a modern environment?