bash 删除csv文件中的空行
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Delete empty lines in csv file
提问by user3344414
I have a file with 4 million of lines, every line ends with the char $, but I mistakenly add a new line after the the line delimiter while scraping a website, so right now it is looking like this:
我有一个包含 400 万行的文件，每一行都以 char $ 结尾，但是我在抓取网站时错误地在行分隔符后添加了一个新行，所以现在它看起来像这样：
fist name, last name, phone, address, postal code, city, region,$
$
fist name, last name, phone, address, postal code, city, region,$
$
the new line '$' only shows up of course if I use :set list, but I'm trying to use this file for a bulk insert in mysql and I'm having problems with it now.
当然，如果我使用 :set list，新行 '$' 只会出现，但我正在尝试使用此文件在 mysql 中进行批量插入，但我现在遇到了问题。
I would like to change the file to:
我想将文件更改为：
fist name, last name, phone, address, postal code, city, region,$
fist name, last name, phone, address, postal code, city, region,$
How can I do this? with sed or awk or even vi ? looked up around and what I found is not really applying to this case.
我怎样才能做到这一点？使用 sed 或 awk 甚至 vi ？环顾四周，我发现的内容并不真正适用于这种情况。
please don't take in consideration the extra empty line shown above.
请不要考虑上面显示的额外空行。
Thanks in advance
提前致谢
回答by Joseph Quinsey
To remove blank lines with sed:
删除空行sed：
sed -i '/^$/d' yourfile.csv
To remove lines consisting of a single $:
要删除由单个 组成的行$：
sed -i '/^$$/d' yourfile.csv
Most versions of sed support the -iswitch; if yours does not you will need e.g. sed '/^$$/d' yourfile.csv > newfile.csv.
大多数版本的 sed 都支持-iswitch；如果你的没有，你将需要例如sed '/^$$/d' yourfile.csv > newfile.csv。
Removing blank lines with white space is more complicated. This usually works:
删除带有空格的空行更为复杂。这通常有效：
sed '/^ *$/d' yourfile.csv
If this is not sufficient, try checking also for tabs. For older sed's, this will work:
如果这还不够，请尝试检查选项卡。对于较旧的 sed，这将起作用：
sed '/^[ X]*$/d' yourfile.csv
where Xhere a tab, entered via Control-VTab.
其中，X在此选项卡，通过进入Control-VTab。
Newer sed's will take a [ \t\r]*or \s*or [[:space:]]*, sometimes requiring a -Eswitch.
较新的 sed 将采用[ \t\r]*or\s*或[[:space:]]*，有时需要-E切换。
回答by that other guy
grepcan filter lines by match (or negative match) against a regex. To exclude empty lines:
grep可以通过匹配（或否定匹配）对正则表达式过滤行。排除空行：
grep -v '^$' yourfile.csv > yourfile_fixed.csv
回答by jaypal singh
Here are your options:
以下是您的选择：
With awk:
与awk：
awk 'NF' file > tmp && mv tmp file
With sed(in-place changes so make sure to backup your file using -i.bak):
使用sed（就地更改，因此请确保使用 备份您的文件-i.bak）：
sed -i '/^$/d' file
With vi:
与vi：
:g/^$/d
