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如何删除每一行末尾的非字母字符？

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如何删除每一行末尾的非字母字符？

我正在尝试删除字母以外的最后一个字符：

support.help1.com,,
support.help1.com.
support.help1.com9
support.help1.com*
support.help1.com@@
support.help1.com##
support.help1.com%%
support.help1.com^
support.help1.com
support.help1.com,
support.help1.com-

我希望我的输出像这样：

support.help1.com
support.help1.com
support.help1.com
support.help1.com
support.help1.com
support.help1.com
support.help1.com
support.help1.com
support.help1.com
support.help1.com
support.help1.com

答案1

sed 也可能有帮助：

command | sed 's/[^a-Z]*$//g'

# create the example output
$ echo "support.help1.com,,
support.help1.com.
support.help1.com9
support.help1.com*
support.help1.com@@
support.help1.com##
support.help1.com%%
support.help1.com^
support.help1.com
support.help1.com,
support.help1.com-" > trailexample.txt

# now edit this stream
# something like $ command_output | sed

$ cat trailexample.txt | sed 's/[^a-Z]*$//g'
support.help1.com
support.help1.com
support.help1.com
support.help1.com
support.help1.com
support.help1.com
support.help1.com
support.help1.com
support.help1.com
support.help1.com
support.help1.com

# explanation
# sed (replace) 's/this/by-this/g' :: sed 's/[^a-Z]*$//g'
# s : substitution command, we want to substitute strings
# The 'this' [^a-Z]*$ : regexp pattern
#   ^ mean not
#   a-Z means all aLphBetiCaL chars
#   []* any number of what is in brackets
#   $ means end of line
# So the 'this' is 'any number of consecutive non-alphabetical chars before end of line'
# And the 'by-this' is empty, nothing, nada, void :: //
# g : global substitution command, means do the replacement for all occurrences

答案2

如果你可以使用正则表达式，只需加载每个命令并使用下面的正则表达式（从这里)：

^(http:\/\/www\.|https:\/\/www\.|http:\/\/|https:\/\/)?[a-z0-9]+([\-\.]{1}[a-z0-9]+)*\.[a-z]{2,5}(:[0-9]{1,5})?(\/.*)?$

此正则表达式接受带有http/ 的URL https。只需使用它来确认您的 URL 是否有效，如果无效，只需通过删除最后一个字符来加载字符串。您可以使用这个解决方法为了那个原因：

string="string.help1.com&&"
foo=string

while [ !regex(foo) ]; do
foo=${foo%?}
done
print foo

注意：regex(foo)只是获取字符串的函数，True如果正则表达式正确则返回，False在其他情况下

NB2：我的语法可能不正确，但这只是给你一个提示

答案3

您可以使用 perl 单行命令来实现此目的：

perl -pne 's/[^a-zA-Z]*$/\n/g' input.txt

这将逐行读取内容，并将行末的input.txt所有非字母字符 ( ) 替换为换行符 ( )[^a-zA-Z]*$\n

答案4

这是一个经典的正则表达式搜索和替换https://regex101.com/r/gRiUTc/2

你可以使用 shell

<input sed -r 's/(\W+|[0-9]+)$//g'

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