diff --git a/sources/tech/20220802 How I use the Linux sed command to automate file edits.md b/sources/tech/20220802 How I use the Linux sed command to automate file edits.md deleted file mode 100644 index 6da228a981..0000000000 --- a/sources/tech/20220802 How I use the Linux sed command to automate file edits.md +++ /dev/null @@ -1,176 +0,0 @@ -[#]: subject: "How I use the Linux sed command to automate file edits" -[#]: via: "https://opensource.com/article/22/8/automate-file-edits-sed-linux" -[#]: author: "Jim Hall https://opensource.com/users/jim-hall" -[#]: collector: "lkxed" -[#]: translator: "perfiffer" -[#]: reviewer: " " -[#]: publisher: " " -[#]: url: " " - -How I use the Linux sed command to automate file edits -====== -Here are some tips and tricks to automating file edits from the Linux command line. - -![computer screen][1] - -Image by: Opensource.com - -When I use the Linux command line, whether I'm writing a new program on my desktop computer or managing a website on my web server, I often need to process text files. Linux provides powerful tools that I leverage to get my work done. I frequently use `sed`, an editor that can modify text according to a pattern. - -`sed` stands for *stream editor*, and it edits text in a file and prints the results. One way to use `sed` is to identify several occurrences of one string in a file and replace them with a different string. You can use `sed` to process text files to a seemingly endless degree, but I'd like to share a few ways I use `sed` to help me manage files. - -### Search and replace text in a file on Linux - -To use `sed`, you need to use a *regular expression*. A regular expression is a set of special characters that define a pattern. My most frequent example of using `sed` is replacing text in a file. The syntax for replacing text looks like this: `s/originaltext/newtext/`. The `s` tells sed to perform text replacement or swap occurrences of text. Provide the original text and new text between slashes. - -This syntax will only replace the first occurrence of `originaltext` on each line. To replace every occurrence, even if the original text appears more than once on a line, append `g` to the end of the expression. Here is an example: `s/originaltext/newtext/g`. - -To use this with `sed`, specify this regular expression with the `-e` option: - -``` -$ sed -e 's/originaltext/newtext/g' -``` - -For example, let's say I have a Makefile for a program called **game**, which simulates Conway's Game of Life: - -``` -.PHONY: all run clean - -all: game - -game: game.o -        $(CC) $(CFLAGS) -o game game.o $(LDFLAGS) - -run: game -        ./game - -clean: -        $(RM) *~ -        $(RM) *.o -        $(RM) game -``` - -The name **game** isn't very descriptive, so I might choose to rename it **life**. Renaming the `game.c` source file to `life.c` is easy enough, but now I need to modify the Makefile to use the new name. I can use `sed` to change every occurrence of **game** to **life**: - -``` -$ sed -e 's/game/life/g' Makefile -.PHONY: all run clean - -all: life - -life: life.o -        $(CC) $(CFLAGS) -o life life.o $(LDFLAGS) - -run: life -        ./life - -clean: -        $(RM) *~ -        $(RM) *.o -        $(RM) life -``` - -This prints the `sed` output to the screen, which is a good way to check if the text replacement will do what you want. To make these changes to the Makefile, first, make a backup of the file, then run `sed` and save the output to the original filename: - -``` -$ cp Makefile Makefile.old -$ sed -e 's/game/life/g' Makefile.old > Makefile -``` - -If you are confident that your changes are exactly what you want, use the `-i` or `--in-place` option to edit the file in place. However, I recommend adding a backup filename suffix like `--in-place=.old` to save a copy of the original file in case you need to restore it later. It looks like this: - -``` -$ sed --in-place=.old -e 's/game/life/g' Makefile -$ ls Makefile* -Makefile  Makefile.old -``` - -### Quoting files with sed on Linux - -You can use other features of regular expressions to match specific instances of text. For example, you might need to replace text that occurs at the start of a line. With `sed`, you can match the beginning of a line with **^**, the caret character. - -One way I use "start of line" in replacing text is when I need to quote a file in an email. Let's say I want to share my Makefile in an email, but I don't want to include it as a file attachment. Instead, I prefer to "quote" the file in the body of an email, using **>** before each line. I can use the following `sed` command to print out an edited version to my terminal, which I can copy and paste into a new email: - -``` -$ sed -e 's/^/>/' Makefile ->.PHONY: all run clean -> ->all: life -> ->life: life.o ->       $(CC) $(CFLAGS) -o life life.o $(LDFLAGS) -> ->run: life ->       ./life -> ->clean: ->       $(RM) *~ ->       $(RM) *.o ->       $(RM) life -``` - -The `s/^/>/` regular expression matches the start of each line (**^**) and places a **>** there. Effectively, this starts each line with the **>** symbol. - -The tabs might not show up correctly in an email, but I can replace all tabs in the Makefile with a few spaces by adding another regular expression: - -``` -$ sed -e 's/^/>/' -e 's/\t/  /g' Makefile ->.PHONY: all run clean -> ->all: life -> ->life: life.o ->  $(CC) $(CFLAGS) -o life life.o $(LDFLAGS) -> ->run: life ->  ./life -> ->clean: ->  $(RM) *~ ->  $(RM) *.o ->  $(RM) life -``` - -The `\t` indicates a literal tab, so `s/\t/ /g` tells sed to replace all tabs in the input with two spaces in the output. - -If you need to apply lots of edits to files, you can save your `-e` commands in a file and use `-f` to tell `sed` to use that file as a "script." This approach is especially useful if you need to make the same edits frequently. I might have prepared the Makefile for quoting in email using a script file called `quotemail.sed` : - -``` -$ cat quotemail.sed -s/^/>/ -s/\t/  /g -$ sed -f quotemail.sed Makefile ->.PHONY: all run clean -> ->all: life -> ->life: life.o ->  $(CC) $(CFLAGS) -o life life.o $(LDFLAGS) -> ->run: life ->  ./life -> ->clean: ->  $(RM) *~ ->  $(RM) *.o ->  $(RM) life -``` - -### Learn to work with sed on Linux - -`sed` is a great tool to keep in your Linux command-line toolkit. Explore the `sed` manual page and learn more about how to use it. Type `man sed` at the command line to get complete documentation about the different command line options and how to use `sed` to process text files. - --------------------------------------------------------------------------------- - -via: https://opensource.com/article/22/8/automate-file-edits-sed-linux - -作者：[Jim Hall][a] -选题：[lkxed][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://opensource.com/users/jim-hall -[b]: https://github.com/lkxed -[1]: https://opensource.com/sites/default/files/lead-images/features_solutions_command_data.png diff --git a/translated/tech/20220802 How I use the Linux sed command to automate file edits.md b/translated/tech/20220802 How I use the Linux sed command to automate file edits.md new file mode 100644 index 0000000000..ac8e94ae0c --- /dev/null +++ b/translated/tech/20220802 How I use the Linux sed command to automate file edits.md @@ -0,0 +1,176 @@ +[#]: subject: "How I use the Linux sed command to automate file edits" +[#]: via: "https://opensource.com/article/22/8/automate-file-edits-sed-linux" +[#]: author: "Jim Hall https://opensource.com/users/jim-hall" +[#]: collector: "lkxed" +[#]: translator: "perfiffer" +[#]: reviewer: " " +[#]: publisher: " " +[#]: url: " " + +我是如何使用 Linux sed 命令自动进行文件编辑 +====== +以下是从 Linux 命令行自动编辑文件的一些提示和技巧。 + +![computer screen][1] + +Image by: Opensource.com + +当我使用 Linux 命令行时，无论是在台式机上编写新程序还是在 Web 服务器上管理网站，我经常需要处理文本文件。Linux 提供了强大的工具，我可以利用这些工具来完成我的工作。我经常使用 `sed`，一个可以根据模式修改文本的编辑器。 + +`sed` 代表 *流编辑器 (stream editor)*，它编辑文件中的文本并打印结果。使用 `sed` 的一种方法是识别一个字符串在文件中出现的次数，并将它们替换为不同的字符串。你可以使用 `sed` 来处理文本文件，其程度似乎无穷无尽，但我想分享一些使用 `sed` 来帮助我管理文件的方法。 + +### 在 Linux 上搜索和替换文件中的文本 + +要使用 `sed`，你需要使用一个*正则表达式*。正则表达式是定义模式的一组特殊字符。我最常使用 `sed` 的例子是替换文件中的文本。替换文本的语法如下：`s/originaltext/newtext`。`s` 告诉 `sed` 执行文本替换或交换出现的文本。在斜线之间提供原始文本和新文本。 + +此语法将仅替换每行中第一次出现的 *原始文本 (originaltext)*。要替换每个匹配项，即使在一行中原始文本出现了不止一次，也要将 `g` 追加到表达式的末尾。例如：`s/originaltext/newtext/g`。 + +要在 `sed` 中使用此表达式，请使用 `-e` 选项指定此正则表达式： + +``` +$ sed -e 's/originaltext/newtext/g' +``` + +例如，假设我有一个名为 **game** 的 Makefile 文件，它模拟了 Conway 的生命游戏： + +``` +.PHONY: all run clean + +all: game + +game: game.o +        $(CC) $(CFLAGS) -o game game.o $(LDFLAGS) + +run: game +        ./game + +clean: +        $(RM) *~ +        $(RM) *.o +        $(RM) game +``` + +**game** 这个名字并不是很有描述性，所以我可能会把它改名为 **life**。将 `game.c` 源文件重命名为 `life.c` 非常简单，但现在我需要修改 Makefile 以使用新名称。我可以使用 `sed` 来将所有的 **game** 更改为 **life**： + +``` +$ sed -e 's/game/life/g' Makefile +.PHONY: all run clean + +all: life + +life: life.o +        $(CC) $(CFLAGS) -o life life.o $(LDFLAGS) + +run: life +        ./life + +clean: +        $(RM) *~ +        $(RM) *.o +        $(RM) life +``` + +`sed` 会将输出打印到屏幕上，这是检查文本替换是否符合你要求的好方法。要对 Makefile 进行这些更改，首先，备份文件，然后运行 `sed` 并将输出保存到原始文件名： + +``` +$ cp Makefile Makefile.old +$ sed -e 's/game/life/g' Makefile.old > Makefile +``` + +如果你确信你的更改正是你想要的，请使用 `-i` 或 `--in-place` 选项来编辑文件。但是，我建议添加一个备份文件后缀，类似于 `--in-place=.old`，用来备份原始文件，以备日后需要恢复时使用。它看起来像这样： + +``` +$ sed --in-place=.old -e 's/game/life/g' Makefile +$ ls Makefile* +Makefile  Makefile.old +``` + +### 在 Linux 上使用 sed 引用文件 + +你可以使用正则表达式的其它功能来匹配特定的文本实例。例如，你可能需要替换出现在行首的文本。使用 `sed`，你可以将行的开头与插入字符 **^** 匹配。 + +我使用“行首”来替换文本的一种方式是当我需要在电子邮件中引用一个文件时。假设我想在电子邮件中共享我的 Makefile，但我不想将其作为文件附件包含在内。相反，我更喜欢在电子邮件正文中“引用”文件，在每行之前使用 **>**。我可以使用以下 `sed` 命令将编辑后的版本打印到我的终端，并将其复制粘贴到新的电子邮件中： + +``` +$ sed -e 's/^/>/' Makefile +>.PHONY: all run clean +> +>all: life +> +>life: life.o +>       $(CC) $(CFLAGS) -o life life.o $(LDFLAGS) +> +>run: life +>       ./life +> +>clean: +>       $(RM) *~ +>       $(RM) *.o +>       $(RM) life +``` + +`s/^/>/` 正则表达式匹配每行的开头（**^**），并在那里放置一个 **>**。实际上，这相当于每行都以 **>** 符号开始。 + +制表符可能无法在电子邮件中正确显示，但我可以通过添加另一个正则表达式将 Makefile 中的所有制表符替换为几个空格： + +``` +$ sed -e 's/^/>/' -e 's/\t/  /g' Makefile +>.PHONY: all run clean +> +>all: life +> +>life: life.o +>  $(CC) $(CFLAGS) -o life life.o $(LDFLAGS) +> +>run: life +>  ./life +> +>clean: +>  $(RM) *~ +>  $(RM) *.o +>  $(RM) life +``` + +`\t` 表示文字制表符，因此 `s/\t/ /g` 告诉 `sed` 用输出中的两个空格替换输入中的所有制表符。 + +如果你需要对文件进行大量编辑，你可以将 `-e` 命令保存在文件中并使用 `-f` 选项来告诉 `sed` 将该文件用作"脚本"。如果你需要经常进行相同的编辑，这种方法特别有用。我已经准备了 `quotemail.sed` 的脚本文件来在我的电子邮件中引用 Makefile： + +``` +$ cat quotemail.sed +s/^/>/ +s/\t/  /g +$ sed -f quotemail.sed Makefile +>.PHONY: all run clean +> +>all: life +> +>life: life.o +>  $(CC) $(CFLAGS) -o life life.o $(LDFLAGS) +> +>run: life +>  ./life +> +>clean: +>  $(RM) *~ +>  $(RM) *.o +>  $(RM) life +``` + +### 学习在 Linux 上使用 sed + +`sed` 是一个很好的工具，可以保存在你的 Linux 命令行工具包中。浏览 `sed` 手册页并了解有关如何使用它的更多信息。在命令行中键入 `man sed` 以获取有关不同命令行选项的完整文档，以及如何使用 `sed` 处理文本文件。 + +-------------------------------------------------------------------------------- + +via: https://opensource.com/article/22/8/automate-file-edits-sed-linux + +作者：[Jim Hall][a] +选题：[lkxed][b] +译者：[perfiffer](https://github.com/perfiffer) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://opensource.com/users/jim-hall +[b]: https://github.com/lkxed +[1]: https://opensource.com/sites/default/files/lead-images/features_solutions_command_data.png