fd（https://github.com/sharkdp/fd ） 是 find 命令的一个更现代的替换。

fd（https://github.com/sharkdp/fd ） is a modern and nicer replacement to the traditional find command.

对比一下 Some comparisons

查找名字含有某个字符的文件 Find a filename with certain string

OLD

-> % find . -name "*hello*"
./courses/hello_world.go
./courses/chapter_01/hello_world.go
./courses/chapter_01/hello_world
./examples/01_hello_world.go

NEW

-> % fd hello
courses/chapter_01/hello_world
courses/chapter_01/hello_world.go
courses/hello_world.go
examples/01_hello_world.go

使用正则表达式查找 Find files using regular expression

比如说查找符合 \d{2}_ti 模式的文件。find 使用的正则表达式非常古老，比如说在这里我们不能使用 \d，也不能使用 {x} 这种语法。因此我们需要对我们的正则表达式做一些改写。关于find支持的正则表达式这里就不展开了。

fd 默认就是使用的正则表达式作为模式，并且默认匹配的是文件名；而 find 默认匹配的是完整路径。另外

For example, let's find a file whose name matches \d{2}_ti. find uses a very ancient form of regular expression. Neither can we use \d, nor can we use {x}. So we have to adjust our expression to these kind of limitations.

fd, by default, uses regular expression as patter, and matches filenames; on the other hand, find uses the -regex option to specify a regular expression, and it matches the whole path.

OLD

-> % find . -regex ".*[0-9][0-9]_ti.*"
./examples/33_tickers.go
./examples/48_time.go
./examples/28_timeouts.go
./examples/50_time_format.go
./examples/32_timers.go

NEW

-> % fd "\d{2}_ti"
examples/28_timeouts.go
examples/32_timers.go
examples/33_tickers.go
examples/48_time.go
examples/50_time_format.go

指定目录 Find in a specific directory

find 的语法是 find DIRECTORY OPTIONS；而 fd 的语法是 fd PATTERN [DIRECTORY]。注意其中目录是可选的。这点个人认为非常好，因为大多数情况下，我们是在当前目录查找，每次都要写 . 非常烦。

find follows the syntax find <directory> <options>; meanwhile, fd uses fd <pattern> [<directory>]. Note that the directory part is optional. AFAIK, this is very convenient. Most of the times, we are just trying to find something in the working directory, typing . each time is very annoying.

OLD

-> % find examples -name "*hello*"
examples/01_hello_world.go

NEW

-> % fd hello examples
examples/01_hello_world.go

直接执行命令 Execute the command without arguments

find 会打印帮助信息，而 fd 则会显示当前目录的所有文件。

find will print help message, fd will print all the files in current directory

OLD

-> % find
usage: find [-H | -L | -P] [-EXdsx] [-f path] path ... [expression]
       find [-H | -L | -P] [-EXdsx] -f path [path ...] [expression]

NEW

-> % fd
courses
courses/chapter_01
courses/chapter_01/chapter_1.md
courses/chapter_01/chapter_1.pdf
courses/chapter_01/hello_world
courses/chapter_01/hello_world.go

按后缀名查找文件 Find files by extension

这是一个很常见的需求，find 中需要使用 -name "*.xxx" 来过滤，而 fd 直接提供了 -e 选项。

It's a very common use case. With find, you have to use -name "*.xxx", while fd provides -e option directly.

OLD

-> % find . -name "*.md"
./courses/chapter_01/chapter_1.md
./courses/chapter_1.md

NEW

-> % fd -e md
courses/chapter_01/chapter_1.md
courses/chapter_1.md

查找中过滤掉 .gitignore 中的文件 Exclude files listed in .gitignore

find 并没有提供对 .gitingnore 文件的原生支持，更好的方法可能是使用 git ls-files。而作为一个现代工具，fd 则默认情况下就会过滤 gitignore 文件，更多情况请查阅文档。

可以使用 -I 来包含这些文件，使用 -H 添加隐藏文件。

find does not natively support .gitignore files, a practical way would be using git ls-files. As a modern tool, fd ignores files listed in .gitignore and hidden files by default.

You could use -I to include those files, -H to also include hidden files.

OLD

-> % git ls-files | grep xxx

NEW

-> % fd xxx

排除某个文件夹 Exclude a directory

fd provides a -E option to exclude directories. You could put the directories in .fdignore, too.

OLD

-> % find . -path ./examples -prune -o -name "*.go"
./courses/hello_world.go
./courses/chapter_01/hello_world.go
./examples

NEW

-> % fd -E examples ".go$"
courses/chapter_01/hello_world.go
courses/hello_world.go

使用 xargs Using xargs

一般来说，如果使用管道过滤的话，需要使用 '\0' 来作为字符串结尾，避免一些潜在的空格引起的问题。

在 find 中需要使用 -print0 来调整输出 '\0' 结尾的字符串，在 xargs 中需要使用 -0 表示接收这种字符串。而在 fd 中，和 xargs 保持了一直，使用 -0 参数就可以了。

If you are using pipes to filter results, using \0 other than \n would be a better option to avoid some potential problems.

find with -print0 will output \0-terminated strings, and xargs's option is -0 to process them. fd chooses -0 as its option, which is consistent with xargs.

OLD

-> % find . -name "*.go" -print0 | xargs -0 wc -l
       7 ./courses/hello_world.go
       7 ./courses/chapter_01/hello_world.go
      50 ./examples/07_switch.go
...

NEW

-> % fd -0 -e go | xargs -0 wc -l
       7 courses/chapter_01/hello_world.go
       7 courses/hello_world.go
       7 examples/01_hello_world.go
...

总之，fd 命令相对于 find 来说相当简单易用了

As you can see, using fd can save you a lot of keystrokes.

PS

使用 exec Using exec

OLD

-> % find . -name "*.md" -exec wc -l {} \;
     114 ./courses/chapter_01/chapter_1.md
     114 ./courses/chapter_1.md

NEW

You could also omit the {}

-> % fd -e md --exec wc -l {}
     114 courses/chapter_1.md
     114 courses/chapter_01/chapter_1.md