VSCode snippets for generating a single-header defines. "#header-single" - generates a template for the header file to be used as a single-file header, "#header-guards" generates the standard guard macros to prevent multiple inclusions of a header file

c.json

    "Create a single header C file": {
        "prefix": "#header-single",
        "body": [
            "#ifndef __${TM_FILENAME_BASE/(.*)/${1:/upcase}/}_H__",
            "#define __${TM_FILENAME_BASE/(.*)/${1:/upcase}/}_H__",
            "$0",
            "#endif // __${TM_FILENAME_BASE/(.*)/${1:/upcase}/}_H__",
            "",
            "#ifdef ${TM_FILENAME_BASE/(.*)/${1:/upcase}/}_IMPLEMENTATION",
            "#endif // ${TM_FILENAME_BASE/(.*)/${1:/upcase}/}_IMPLEMENTATION"
        ],
        "description": "Generate a C header file template with proper header guards, https://github.com/nothings/stb/blob/master/docs/stb_howto.txt"
    },
    "Create header guards": {
        "prefix": "#header-guards",
        "body": [
            "#ifndef __${TM_FILENAME_BASE/(.*)/${1:/upcase}/}_H__",
            "#define __${TM_FILENAME_BASE/(.*)/${1:/upcase}/}_H__",
            "$0",
            "#endif // __${TM_FILENAME_BASE/(.*)/${1:/upcase}/}_H__"
        ],
        "description": "Quickly generate header guards"
    }