如何使用bash解析字符串以获取数字 [英] How can I parse a string using bash to get a number

问题描述

我有以下字符串:

PR-1769|7bb12d4152a497cef491e0a1088b3984ad92972f|jaga|

如何使用bash解析上面的字符串，以便获得 1769 ?

How can I parse the string above using bash so that I get the 1769?

另外，如何使用bash获取最后一个字符串 jaga ?

Also, how do I get the last string jaga using bash?

推荐答案

这里不需要 grep :bash具有内置的正则表达式支持，非常使用效率比启动外部实用程序(仅用于处理一行)的效率要高:

There's no need for grep here: bash has built-in regex support, which is vastly more efficient to use than starting up an external utility just to process a single line:

re='^PR-([0-9]+)'
s='PR-1769|7bb12d4152a497cef491e0a1088b3984ad92972f|marvel|'

if [[ $s =~ $re ]]; then
  echo "Matched: ${BASH_REMATCH[1]}"
fi

---

您还可以使用参数扩展:

---

You can also use parameter expansions:

s='PR-1769|7bb12d4152a497cef491e0a1088b3984ad92972f|marvel|'
s="${s%%'|'*}" # trim off everything after the first |
s="${s#PR-}"   # trim off the leading PR
echo "$s"

---

顺便说一句，如果您需要提取各个字段，那么 read 可能是该工作的正确工具:

---

If you needed to extract the individual fields, by the way, read might be the correct tool for the job:

s='PR-1769|7bb12d4152a497cef491e0a1088b3984ad92972f|marvel|'
IFS='|' read -r pr hash username <<<"$s"

...上面将把 PR-1769 放入变量 pr 中，将 7bb12d4152a497cef491e0a1088b3984ad92972f 放入变量 hash ，然后将 marvel 放入变量 username 中.那么，要剥离 PR-，可能看起来像这样:

...the above will put PR-1769 into the variable pr, 7bb12d4152a497cef491e0a1088b3984ad92972f into the variable hash, and marvel into the variable username. To strip off the PR-, then, might simply look like:

echo "${pr#PR-}"

...或打印提取的用户名:

...or, to print the extracted username:

echo "$username"

---

请参阅:

---

See:

• BashFAQ#100 (如何在bash中进行字符串操作?")
• bash-hackers.org参数扩展参考

• BashFAQ #100 ("How do I do string manipulations in bash?")
• bash-hackers.org parameter expansion reference

这篇关于如何使用bash解析字符串以获取数字的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！