内容简介:Have you ever thought how good it would be to have a help message for your shell script that you wrote a month ago and already forgot what it is supposed to do?Yeah, there is always a way to show a message using cat (meow) or a bunch of echo calls.But ther
Have you ever thought how good it would be to have a help message for your shell script that you wrote a month ago and already forgot what it is supposed to do?
Yeah, there is always a way to show a message using cat (meow) or a bunch of echo calls.
But there is a neat trick.
Add your message with all the required information on top of your file, just right after the shebang.
#!/bin/bash ### ### my-script — does one thing well ### ### Usage: ### my-script <input> <output> ### ### Options: ### <input> Input file to read. ### <output> Output file to write. Use '-' for stdout. ### -h Show this message.
Halfway done, now need to get this message in runtime with sed.
help() {
sed -rn 's/^### ?//;T;p' "$0"
}
$0
means a filename of a file that is being executed.
A bit about the magic that is going here:
s / ^### ? // T p
Now just call the help
function if an arg -h
or no args passed.
if [[ $# == 0 ]] || [[ "$1" == "-h" ]]; then
help
exit 1
fi
Hope it helps, cheers!
Full gist is available on GitHub: https://gist.github.com/kovetskiy/a4bb510595b3a6b17bfd1bd9ac8bb4a5
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网络、群体与市场
大卫·伊斯利(David Esley)、乔恩·克莱因伯格(Jon Kleinberg) / 李晓明、王卫红、杨韫利 / 清华大学出版社 / 2011-10-1 / CNY 69.00
过去十年来,现代社会中复杂的连通性向公众展现出与日俱增的魅力。这种连通性在许多方面都有体现并发挥着强大的作用,包括互联网的快速成长、全球通信的便捷,以及新闻与信息(及传染病与金融危机)以惊人的速度与强度传播的能力。这种现象涉及网络、动机和人们的聚合行为。网络将人们的行为联系起来,使得每个人的决定可能对他人产生微妙的后果。 本书是本科生的入门教材,同时也适合希望进入相关领域的高层次读者。它从交......一起来看看 《网络、群体与市场》 这本书的介绍吧!