RM失败时从脚本通配符来删除文件，而是从shell提示下工作 [英] rm fails to delete files by wildcard from a script, but works from a shell prompt

问题描述

我碰到一个Linux的shell脚本一个非常愚蠢的问题。我想删除与目录中的扩展名，操作.bz2的所有文件。在剧本我称之为

I've run into a really silly problem with a Linux shell script. I want to delete all files with the extension ".bz2" in a directory. In the script I call

rm "$archivedir/*.bz2"

其中$ archivedir是一个目录路径。应该是pretty简单，不应该吗？不知何故，它管理的失败，此错误：

where $archivedir is a directory path. Should be pretty simple, shouldn't it? Somehow, it manages to fail with this error:

rm: cannot remove `/var/archives/monthly/April/*.bz2': No such file or directory

但是的在该目录中名为test.bz2一个文件，如果我改变我的脚本

But there is a file in that directory called test.bz2 and if I change my script to

echo rm "$archivedir/*.bz2"

和复制/该行的输出粘贴到一个终端窗口中的文件被成功删除。我在做什么错了？

and copy/paste the output of that line into a terminal window the file is removed successfully. What am I doing wrong?

推荐答案

要扩大多一点：

• 在Unix中，程序一般不跨preT通配符自己。外壳间$ P $点不带引号的通配符，并替换匹配的文件名列表中的每个通配符参数。
  如果$ archivedir可能包含空格，则 RM $ archivedir / *。BZ2 可能不会做你

您可以通过引用通配符，使用双或单引号，或前一个反斜杠禁用此过程。然而，这不是你想要的这里 - 你想扩展到文件列表中的通配符，它​​匹配

You can disable this process by quoting the wildcard character, using double or single quotes, or a backslash before it. However, that's not what you want here - you do want the wildcard expanded to the list of files that it matches.

要小心写 RM $ archivedir / *。BZ2 （不带引号）。这个词拆分（即，打破了命令行成参数）发生的之后的$ archivedir被取代。所以，如果$ archivedir包含空格，那么你会得到你不打算额外的参数。说archivedir是的/ var /档案馆/每月/四月到六月。然后你会得到书面相当于 RM的/ var /档案馆/每月/四月它试图删除文件六月/ *。BZ2 ，在/ var /档案馆/每月/月，来，和匹配所有文件六一/ *。BZ2，这是不是你想要的。

Be careful about writing rm $archivedir/*.bz2 (without quotes). The word splitting (i.e., breaking the command line up into arguments) happens after $archivedir is substituted. So if $archivedir contains spaces, then you'll get extra arguments that you weren't intending. Say archivedir is /var/archives/monthly/April to June. Then you'll get the equivalent of writing rm /var/archives/monthly/April to June/*.bz2, which tries to delete the files "/var/archives/monthly/April", "to", and all files matching "June/*.bz2", which isn't what you want.

正确的解决办法是写：

rm "$archivedir"/*.bz2

这篇关于RM失败时从脚本通配符来删除文件，而是从shell提示下工作的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！