使用 grep 就地处理 [英] In-place processing with grep

问题描述

我有一个调用 grep 来处理文本文件的脚本.目前我正在做这样的事情.

I've got a script that calls grep to process a text file. Currently I am doing something like this.

$ grep 'SomeRegEx' myfile.txt > myfile.txt.temp
$ mv myfile.txt.temp myfile.txt

我想知道是否有任何方法可以进行就地处理，例如将结果存储到同一个原始文件中，而无需创建临时文件，然后在处理完成后用临时文件替换原始文件.

I'm wondering if there is any way to do in-place processing, as in store the results to the same original file without having to create a temporary file and then replace the original with the temp file when processing is done.

当然，我欢迎评论为什么应该或不应该这样做，但我主要感兴趣的是它是否可以.在这个例子中，我使用了 grep，但我对 Unix 工具很感兴趣.谢谢！

Of course I welcome comments as to why this should or should not be done, but I'm mainly interested in whether it can be done. In this example I'm using grep, but I'm interested about Unix tools in general. Thanks!

推荐答案

Perl 有 -i 开关，sed 和 Ruby 也有

Perl has the -i switch, so does sed and Ruby

sed -i.bak -n '/SomeRegex/p' file

ruby -i.bak -ne 'print if /SomeRegex/' file

但请注意，它所做的只是在后端创建您认为看不到的临时"文件，仅此而已.

But note that all it ever does is creating "temp" files at the back end which you think you don't see, that's all.

其他方式，除了grep

awk

awk '/someRegex/' file > t && mv t file

重击

while read -r line;do case "$line" in *someregex*) echo "$line";;esac;done <file > t && mv t file

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