About

Kapow is a template processor that provides the following directives to support injecting file contents, command output, current date/time, elapsed time, etc in generated output.

It can be used in some different ways:

• Standard: Create a (Markdown) file with kapow directives then run kapow [OPTIONS] path/to/file.ext; optionally save the output via redirection: kapow [OPTIONS] path/to/file.ext >output.ext
• Shebang: Place #!/usr/bin/env kapow as the first line of a (Markdown) file, make it "executable" via chmod +x file.ext, then run via ./file.ext (see note #3 under [block directives]). Use env's -S option if passing options to kapow, for example: #!/usr/bin/env -S kapow -w 60.

While kapow is designed around Markdown syntax, it can be used with any text format that works with its directives.

Block directives

Directive | Description ---|--- !inc:path | Include file contents; path is relative to its containing file !run:command | Run command and insert stdout

Notes:

1. Block directives must be placed at the beginning of a line.
2. Long commands can be backslash-wrapped.
3. Included file paths and commands are processed from the directory where the source file is located when it is passed as an argument. However, if the source file is read on stdin or run via shebang, included file paths and commands are processed relative to the current directory. So, if any included files use relative paths or commands that depend on the current directory, it will be necessary to manually change to the source file's directory and then run via ./file.ext.
4. Block directives are entirely replaced by their contents/output, so you are free to embed them inside or as Markdown syntax... for example, as listing contents, prepend a prompt showing the command, etc.
5. If a !run directive fails, kapow prints the error and stops processing, unless the user specifies the -k option.

Span directives

Directive | Example | Description ---|---|--- `!elapsed` | 0s | Processing time `!now` | 2023-07-06T08:54:53Z | Current date/time in UTC / RFC 3339 `!now:local` | Thu 06 Jul 2023 04:54:53 EDT | Current date/time in local timezone `!now:local:%A %H:%M` | Thursday 04:54 | Current date/time in local timezone and custom format `!now:MST7MDT` | Thu 06 Jul 2023 02:54:53 MDT | Current date/time in custom timezone `!now:MST7MDT:%A %H:%M` | Thursday 02:54 | Current date/time in custom timezone and format `!now:US/Hawaii` | Wed 05 Jul 2023 22:54:53 HST | Current date/time in custom locale `!now:US/Hawaii:%A %H:%M` | Wednesday 22:54 | Current date/time in custom locale and format `!now:UTC:%A %H:%M` | Thursday 08:54 | Current date/time in UTC and custom format `!now:x` | Xh658sr | Current date/time in "x" format `!today` | 2023-07-06 | Current date in UTC / RFC 3339 `!today:local` | 2023-07-06 | Current date in local timezone `!today:MST7MDT` | 2023-07-06 | Current date in custom timezone `!today:MST7MDT:%v` | 6-Jul-2023 | Current date in custom timezone and format `!today:US/Hawaii` | 2023-07-05 | Current date in custom locale `!today:US/Hawaii:%x` | 07/05/23 | Current date in custom locale and format `!today:UTC:%A` | Thursday | Current date in UTC and custom format

• Span directives must be placed inside a code span and may appear zero or more times in any line.
• Disable processing a span directive by escaping ! with a backslash: \!.

Install

bash cargo install kapow bat

NOTE: Installing [bat] is optional, but if installed, kapow uses it for syntax highlighting and paging (see the -p, -P, -H, -l, and -r options); also it's a nice utility to have around.

Usage

text $ kapow -V kapow 2.11.0

```text $ kapow -h KAPOW!

Usage: kapow [OPTIONS] [PATH]...

Arguments: [PATH]... Source file(s) [default: -]

Options: -p Page output -P Do not page output -H Disable syntax highlighting -L Display all syntax highlight languages -l Syntax higlight language [default: md] -w Wrap !run directive columns [default: 0] -c Wrap !run directive continuation [default: ] -k Ignore !run directive failures -r, --readme Print readme -h, --help Print help -V, --version Print version ```

Errors

Code | Description ---|--- 101 | Could not read input file 102 | Could not read included file 103 | Could not change directory 104 | !run directive command failed

NOTE: The kapow process may not appear to have exited with these error codes in "normal usage" because output is piped to [bat] as a pager if it is installed and output is a TTY and unfortunately [bat] masks the error code.

Example

See the readme task in Makefile.toml:

• Generates t/VERSION.md from t/VERSION.t.md
  • !run:../target/release/kapow -V
• Generates t/USAGE.md from t/USAGE.t.md
  • !run:../target/release/kapow -h
• Generates README.md from t/README.md
  • !inc:VERSION.md
  • !inc:USAGE.md
  • `!now` (all variants)

Changelog

Please find the [CHANGELOG.md] in the [repository].

Development

bash cargo install cargo-audit cargo-edit cargo-make cargo-outdated dtg \ kapow miniserve