> For the complete documentation index, see [llms.txt](https://samypesse.gitbook.io/how-to-create-an-operating-system/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://samypesse.gitbook.io/how-to-create-an-operating-system/unix-basic-tools-sh-cat.md).

# UNIX basic tools: sh, cat