From 98d37b665fa7fbf531421a8268405c0cb899b92d Mon Sep 17 00:00:00 2001 From: rwxrob Date: Fri, 6 Aug 2021 13:48:11 -0400 Subject: [PATCH] Add initial boilerplate files --- DCO | 36 ++++++++++ LICENSE | 201 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ README.md | 92 +++++++++++++++++++++++++ cmd | 145 +++++++++++++++++++++++++++++++++++++++ 4 files changed, 474 insertions(+) create mode 100644 DCO create mode 100644 LICENSE create mode 100644 README.md create mode 100755 cmd diff --git a/DCO b/DCO new file mode 100644 index 0000000..36fe7b6 --- /dev/null +++ b/DCO @@ -0,0 +1,36 @@ +Developer Certificate of Origin +Version 1.1 + +Copyright (C) 2004, 2006 The Linux Foundation and its contributors. +1 Letterman Drive +Suite D4700 +San Francisco, CA, 94129 + +Everyone is permitted to copy and distribute verbatim copies of this +license document, but changing it is not allowed. + +Developer's Certificate of Origin 1.1 + +By making a contribution to this project, I certify that: + +(a) The contribution was created in whole or in part by me and I + have the right to submit it under the open source license + indicated in the file; or + +(b) The contribution is based upon previous work that, to the best + of my knowledge, is covered under an appropriate open source + license and I have the right under that license to submit that + work with modifications, whether created in whole or in part + by me, under the same open source license (unless I am + permitted to submit under a different license), as indicated + in the file; or + +(c) The contribution was provided directly to me by some other + person who certified (a), (b) or (c) and I have not modified + it. + +(d) I understand and agree that this project and the contribution + are public and that a record of the contribution (including all + personal information I submit with it, including my sign-off) is + maintained indefinitely and may be redistributed consistent with + this project or the open source license(s) involved. diff --git a/LICENSE b/LICENSE new file mode 100644 index 0000000..e0b334b --- /dev/null +++ b/LICENSE @@ -0,0 +1,201 @@ + Apache License + Version 2.0, January 2004 + http://www.apache.org/licenses/ + + TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION + + 1. 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However, in accepting such obligations, You may act only + on Your own behalf and on Your sole responsibility, not on behalf + of any other Contributor, and only if You agree to indemnify, + defend, and hold each Contributor harmless for any liability + incurred by, or claims asserted against, such Contributor by reason + of your accepting any such warranty or additional liability. + + END OF TERMS AND CONDITIONS + + APPENDIX: How to apply the Apache License to your work. + + To apply the Apache License to your work, attach the following + boilerplate notice, with the fields enclosed by brackets "{}" + replaced with your own identifying information. (Don't include + the brackets!) The text should be enclosed in the appropriate + comment syntax for the file format. We also recommend that a + file or class name and description of purpose be included on the + same "printed page" as the copyright notice for easier + identification within third-party archives. + + Copyright 2020 Rob Muhlestein + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. diff --git a/README.md b/README.md new file mode 100644 index 0000000..50213b9 --- /dev/null +++ b/README.md @@ -0,0 +1,92 @@ +# Bash Command Boilerplate + +This is a GitHub template repo that will be copied instead of forked +to create a new Bash command. Obviously, not all of this is needed for +many Bash scripts, but anything with more than two subcommands will +benefit from the builtin tab completion, embedded Markdown help +documentation support, and included functions (`usage`, `_filter`, +`_filterbuf`, `_have`, etc.) + +## Usage + +``` +command +command usage +command help [] +command foo [] +command bar [] +``` + +## Commands + +| Command | Summary | +| :-: | - | +| [usage] | Display single line summary of all command usage | +| [help] | Display help information | +| [foo] | Do the foo | +| [bar] | Do the bar | + +[usage]: #usage +[help]: #help +[foo]: #foo +[bar]: #bar + +### `usage` + +The `usage` command displays a summary of usage. + +### `help` + +The help command prints help information. If no argument is passed +displays general help information (main). Otherwise, the documentation +for the specific argument keyword is displayed, which usually +corresponds to a command name (but not necessarily). All documentation +is written in CommonMark (Markdown) and will displayed as Web page if +`pandoc` and `$HELP_BROWSER` are detected, otherwise, just the Markdown is +sent to `$PAGER` (default: `more`). + +## `foo` + +The `foo` command foos. + +## `bar` + +The `bar` command bars. + +## Dependencies + +Required: + +* Bash 4+ + +Optional: + +* `pandoc` - for rich help docs + +## Justification + +Bash is the dominate shell scripting language and the official default +Linux interactive shell, which reduces cognitive overhead; every command +line *is* a line of code that could be put into script as is. Bash +scripts are at the core of cloud, containers, and Kubernetes. Bash 4+ +with its associative array support, powerful regular expressions, and +multiple ways of feeding data to loops easily covers the needs +previously requiring Python and Perl scripts. Bash scripts are also much +more powerful, safer, flexible, and performant than POSIX shell or Zsh. + +## Caveats + +* Use the official bash path: `#!/usr/bin/bash` +* Using `#!/usr/bin/env bash` introduces unnecessary risk +* Always set the acceptable `PATH` at beginning of script +* Always check script with [`shellcheck`] before releasing +* Always use `bc` for *any* floating point math + +[`shellcheck`]: + +## Legal + +Copyright 2021 Rob Muhlestein +Released under Apache-2.0 License +Please mention + diff --git a/cmd b/cmd new file mode 100755 index 0000000..809570e --- /dev/null +++ b/cmd @@ -0,0 +1,145 @@ +#!/usr/bin/bash +# shellcheck disable=SC2016 +set -e +export PATH="/usr/bin:/usr/local/bin" + +# Copyright 2021 Rob Muhlestein +# Released under Apache-2.0 license +# Please mention https://youtube.com/rwxrob + +(( BASH_VERSINFO[0] < 4 )) && echo "Bash 4+ required." && exit 1 + +: "${PAGER:=more}" +: "${EDITOR:=vi}" +: "${HELP_BROWSER:=}" + +EXE="${0##*/}" + +declare -A help # associative arrays *require* declaration + +help[main]=' +This snippet contains the scaffolding for Bash tab completion using +the complete -C foo foo variation which allows scripts to complete +themselves (rather than having another script somewhere to manage). To +use it simply add a function with the additional command and add the +name of it to the commands array declaration at the top of the script. +Then add complete -C foo foo (or something like it) to your bashrc. +Begin functions with x_ to allow useful command names to be used that +would otherwise conflict with existing system and bash keywords. Begin +functions with x__ when you do not want them to appear with tab +completion, but still want them to be avaiable, just hidden. +' + +help[foo]='The `foo` command foos.' + +x_foo() { + _filter "$@" && return $? + echo "would foo: $*" +} + +help[bar]='The `bar` command bars.' + +x_bar() { + _filterbuf "$@" && return $? + echo "would bar: $*" +} + +x__hidden() { + _filter "$@" && return $? + echo "would run _hidden: $*" +} + +help[usage]='The `usage` command displays a summary of usage.' + +x_usage() { + local -a cmds + for c in "${COMMANDS[@]}"; do + [[ ${c:0:1} =~ _ ]] && continue + cmds+=($c) + done + cmds="${cmds[*]}" + printf "usage: %s (%s)\n" "$EXE" "${cmds// /|}" +} + +help[help]=' +The `help` command prints help information. If no argument is passed +displays general help information (main). Otherwise, the documentation +for the specific argument keyword is displayed, which usually +corresponds to a command name (but not necessarily). All documentation +is written in CommonMark (Markdown) and will displayed as Web page if +`pandoc` and `$HELP_BROWSER` are detected, otherwise, just the Markdown is +sent to `$PAGER` (default: more).' + +x_help() { + local name="$1" + if [[ -z "$name" ]];then + for c in "${COMMANDS[@]}";do + x_help "$c" buildonly + done + x_help main + return 0 + fi + local title="$EXE $name" + [[ $name = main ]] && title="$EXE" + local file="/tmp/help-$EXE-$name.html" + if _have pandoc ; then + if _have "$HELP_BROWSER" && [[ -t 1 ]] ;then + pandoc -s --metadata title="$title" \ + -o "$file" <<< "${help[$name]}" + [[ -z "$2" ]] && cd /tmp && exec "$HELP_BROWSER" "$file" + return 0 + fi + pandoc -s --metadata title="$title" \ + -t plain <<< "${help[$name]}" | "$PAGER" + return 0 + fi + echo "${help[$name]}" | "$PAGER" +} + +# --------------------- completion and delegation -------------------- + +_have(){ type "$1" &>/dev/null; } + +_filter(){ + [[ -n "$1" ]] && return 1 + while IFS= read -ra args; do + "${FUNCNAME[1]}" "${args[@]}" + done +} + +_filterbuf() { + [[ -n "$1" ]] && return 1 + "${FUNCNAME[1]}" "$(