查找文件类型的shell脚本 [英] shell script to find file type

问题描述

我正在编写一个 shell 脚本，它接受一个命令行参数，一个文件路径(可能是相对的或绝对的).脚本应检查该文件并打印一行包含以下短语的行:

I am working on a shell script that takes a single command line parameter, a file path (might be relative or absolute). The script should examine that file and print a single line consisting of the phrase:

Windows ASCII

Windows ASCII

如果文件是带有 CR/LF 行终止符的 ASCII 文本文件，或者

if the files is an ASCII text file with CR/LF line terminators, or

别的东西

如果文件是二进制或带有Unix"LF 行终止符的 ASCII.

if the file is binary or ASCII with "Unix" LF line terminators.

目前我有以下代码.

#!/bin/sh
file=$1
if grep -q "\r\n" $file;then
echo Windows ASCII
else
echo Something else
fi

它正确显示信息，但是当我通过诸如/bin/cat 之类的不是 Windows ASCII 类型的内容时，它仍然将其标识为 Windows ASCII.当我传递 .txt 文件类型时，它会按预期显示其他内容，它只是在显示 Windows ASCII 的文件夹上.我想我没有正确处理它，但我不确定.有关如何解决此问题的任何指示?

It displays information properly, but when I pass something that is not of Windows ASCII type through such as /bin/cat it still id's it as Windows ASCII. When I pass a .txt file type it displays something else as expected it is just on folders that it displays Windows ASCII. I think I am not handling it properly, but I am unsure. Any pointers of how to fix this issue?

推荐答案

当你指定你只需要区分两种情况时，这应该有效.

As you specify you only need to differentiate between 2 cases, this should work.

#!/bin/sh
file="$1"
case $(file "$file") in
  *"ASCII text, with CRLF line terminators" )
     echo "Windows ASCII"
  ;;
  * )
     echo "Something else"
  ;;
esac

正如您指定的#!/bin/sh，或者如果您的目标是完全向后兼容，您可能需要更改

As you have specified #!/bin/sh, OR if your goal is total backward compatibility, you may need to change

$(file "$file")

与

`file "$file"`

要使用包含空格的文件名的脚本，请注意所有 $ 变量名称现在都用双引号括起来.并且您还必须在调用脚本时引用文件名中的空格字符，即

To use your script with filenames that include spaces, note that all $ variable names are now surrounded with double-quotes. AND you'll also have to quote the space char in the filename when you call the script, i.e.

 myFileTester.sh "file w space.txt"
 OR
 myFileTester.sh 'file w space.txt'
 OR
 myFileTester.sh file\ w\ space.txt
 OR

<小时>

此外，如果您必须开始区分 file 可以分析的所有可能的情况，那么您将拥有一个相当大的 case 语句.AND file 因其返回的不同消息而臭名昭著，这取决于 /etc/file/magic 的内容、操作系统、版本等.

---

Also, if you have to start discriminating all the possible cases that file can analyze, you'll have a rather large case statement on your hands. AND file is notorious for the different messages it returns, depending on the the contents of /etc/file/magic, OS, versions, etc.

IHTH

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