bash 检查字符串是否只包含指定的字符，包括下划线
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/20763980/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Check if a string contains only specified characters including underscores
提问by Khaleal
I want to receive a string (one word) from the user, with the following criteria: The string may contain only alphabetical characters (aA-zZ) and underscores. Digits and other characters are not allowed.
我想从用户那里接收一个字符串（一个单词），符合以下条件：该字符串可能只包含字母字符 (aA-zZ) 和下划线。不允许使用数字和其他字符。
How may I do this in BASH?
我怎么能在 BASH 中做到这一点？
回答by lilydjwg
Use =~to check a string against a (POSIX extended) regex. See manpages bash(1)and regex(7)for more.
用于=~根据（POSIX 扩展）正则表达式检查字符串。请参阅联机帮助页bash(1)和regex(7)更多信息。
# assume your string is in variable $s
if [[ $s =~ ^[A-Za-z_]+$ ]]; then
# it matches
else
# doesn't match
fi
