为了避免出现“权限被拒绝”警告，请告诉find通过从搜索中删除不可读的文件来忽略它们。将表达式作为OR添加到查找中，例如

find / \! -readable -prune -o -name '*.jbd' -ls

这主要是说(匹配一个不可读的文件并将其从列表中删除)或(匹配一个像*这样的名称。JBD和显示它[与ls])。(请记住，默认情况下表达式是AND'd，除非使用-or。)您需要在第二个表达式中使用-ls，否则find可能会添加一个默认操作来显示任何一个匹配，这也将显示所有不可读的文件。

但是如果你在你的系统中寻找真实的文件，通常没有理由去找/dev，因为那里有很多很多的文件，所以你应该添加一个表达式来排除这个目录，比如:

find / -mount \! -readable -prune  -o  -path /dev -prune  -o  -name '*.jbd' -ls

所以(匹配不可读的文件并从列表中修剪)或(匹配路径/dev并从列表中修剪)或(匹配像*。JBD并显示它)。

Use:

find . 2>/dev/null > files_and_folders

当然，这不仅隐藏了Permission denied错误，还隐藏了所有错误消息。

如果你真的想保留其他可能的错误，比如符号链接上的跳数太多，而不是权限被拒绝的那些，那么你可能不得不大胆猜测你没有很多被称为“权限被拒绝”的文件，然后尝试:

find . 2>&1 | grep -v 'Permission denied' > files_and_folders

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如果你只想过滤标准误差，你可以使用更精细的结构:

find . 2>&1 > files_and_folders | grep -v 'Permission denied' >&2

The I/O redirection on the find command is: 2>&1 > files_and_folders |. The pipe redirects standard output to the grep command and is applied first. The 2>&1 sends standard error to the same place as standard output (the pipe). The > files_and_folders sends standard output (but not standard error) to a file. The net result is that messages written to standard error are sent down the pipe and the regular output of find is written to the file. The grep filters the standard output (you can decide how selective you want it to be, and may have to change the spelling depending on locale and O/S) and the final >&2 means that the surviving error messages (written to standard output) go to standard error once more. The final redirection could be regarded as optional at the terminal, but would be a very good idea to use it in a script so that error messages appear on standard error.

这个主题有无穷无尽的变化，取决于你想做什么。这将在任何带有任何Bourne shell衍生物(Bash, Korn，…)的Unix变体和任何posix兼容版本的find上工作。

如果您希望适应系统上的find的特定版本，可能有可用的替代选项。特别是GNU find有许多其他版本没有的选项-请参阅当前接受的一组选项的答案。

注意:

这个答案可能比用例更深入，在许多情况下，找到2>/dev/null就足够了。从跨平台的角度来看，它可能仍然是有兴趣的，它讨论了一些先进的shell技术，以便找到尽可能健壮的解决方案，尽管所防范的情况可能主要是假设的。

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如果你的shell是bash或zsh，有一种解决方案既健壮又相当简单，只使用posix兼容的查找特性;虽然bash本身不是POSIX的一部分，但大多数现代Unix平台都附带了它，使得这个解决方案具有广泛的可移植性:

find . > files_and_folders 2> >(grep -v 'Permission denied' >&2)

注意:

If your system is configured to show localized error messages, prefix the find calls below with LC_ALL=C (LC_ALL=C find ...) to ensure that English messages are reported, so that grep -v 'Permission denied' works as intended. Invariably, however, any error messages that do get displayed will then be in English as well. >(...) is a (rarely used) output process substitution that allows redirecting output (in this case, stderr output (2>) to the stdin of the command inside >(...). In addition to bash and zsh, ksh supports them as well in principle, but trying to combine them with redirection from stderr, as is done here (2> >(...)), appears to be silently ignored (in ksh 93u+). grep -v 'Permission denied' filters out (-v) all lines (from the find command's stderr stream) that contain the phrase Permission denied and outputs the remaining lines to stderr (>&2). Note: There's a small chance that some of grep's output may arrive after find completes, because the overall command doesn't wait for the command inside >(...) to finish. In bash, you can prevent this by appending | cat to the command.

这种方法是:

鲁棒性:grep仅应用于错误消息(而不应用于文件路径和错误消息的组合，可能会导致误报)，并且将权限拒绝的错误消息以外的错误消息传递给stderr。 副作用free: find的退出代码被保留:无法访问遇到的至少一个文件系统项导致退出代码1(尽管它不会告诉您是否发生了权限拒绝之外的错误)。

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posix兼容的解决方案:

完全符合posix的解决方案要么有限制，要么需要额外的工作。

如果find的输出无论如何都要被捕获到文件中(或者完全被抑制)，那么Jonathan Leffler给出的基于管道的解决方案是简单、健壮且符合posix的:

find . 2>&1 >files_and_folders | grep -v 'Permission denied' >&2

注意，重定向的顺序很重要:2>和1必须先出现。

预先在文件中捕获stdout输出允许2>&1仅通过管道发送错误消息，然后grep可以明确地对其进行操作。

The only downside is that the overall exit code will be the grep command's, not find's, which in this case means: if there are no errors at all or only permission-denied errors, the exit code will be 1 (signaling failure), otherwise (errors other than permission-denied ones) 0 - which is the opposite of the intent. That said, find's exit code is rarely used anyway, as it often conveys little information beyond fundamental failure such as passing a non-existent path. However, the specific case of even only some of the input paths being inaccessible due to lack of permissions is reflected in find's exit code (in both GNU and BSD find): if a permissions-denied error occurs for any of the files processed, the exit code is set to 1.

下面的变体解决了这个问题:

find . 2>&1 >files_and_folders | { grep -v 'Permission denied' >&2; [ $? -eq 1 ]; }

现在，退出代码指示是否发生了除Permission denied之外的任何错误:如果是1，否则为0。 换句话说:退出码现在反映了命令的真实意图:如果根本没有错误或只发生了权限拒绝错误，则报告success(0)。 可以说，这甚至比在顶部的解决方案中传递find的退出代码更好。

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gniourf_gniourf在评论中提出了一个使用复杂重定向的解决方案的泛化(仍然符合posix)，即使在将文件路径打印到stdout的默认行为下也能工作:

{ find . 3>&2 2>&1 1>&3 | grep -v 'Permission denied' >&3; } 3>&2 2>&1

简而言之:自定义文件描述符3用于临时交换stdout(1)和stderr(2)，这样错误消息就可以单独通过stdout传输到grep。

如果没有这些重定向，数据(文件路径)和错误消息都将通过stdout管道传输到grep，然后grep将无法区分错误消息Permission denied和名称碰巧包含短语Permission denied的(假设的)文件。

然而，与第一个解决方案一样，报告的退出码将是grep的，而不是find的，但可以应用与上面相同的修复。

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关于现有答案的说明:

There are several points to note about Michael Brux's answer, find . ! -readable -prune -o -print: It requires GNU find; notably, it won't work on macOS. Of course, if you only ever need the command to work with GNU find, this won't be a problem for you. Some Permission denied errors may still surface: find ! -readable -prune reports such errors for the child items of directories for which the current user does have r permission, but lacks x (executable) permission. The reason is that because the directory itself is readable, -prune is not executed, and the attempt to descend into that directory then triggers the error messages. That said, the typical case is for the r permission to be missing. Note: The following point is a matter of philosophy and/or specific use case, and you may decide it is not relevant to you and that the command fits your needs well, especially if simply printing the paths is all you do: If you conceptualize the filtering of the permission-denied error messages a separate task that you want to be able to apply to any find command, then the opposite approach of proactively preventing permission-denied errors requires introducing "noise" into the find command, which also introduces complexity and logical pitfalls. For instance, the most up-voted comment on Michael's answer (as of this writing) attempts to show how to extend the command by including a -name filter, as follows: find . ! -readable -prune -o -name '*.txt' This, however, does not work as intended, because the trailing -print action is required (an explanation can be found in this answer). Such subtleties can introduce bugs. The first solution in Jonathan Leffler's answer, find . 2>/dev/null > files_and_folders, as he himself states, blindly silences all error messages (and the workaround is cumbersome and not fully robust, as he also explains). Pragmatically speaking, however, it is the simplest solution, as you may be content to assume that any and all errors would be permission-related. mist's answer, sudo find . > files_and_folders, is concise and pragmatic, but ill-advised for anything other than merely printing filenames, for security reasons: because you're running as the root user, "you risk having your whole system being messed up by a bug in find or a malicious version, or an incorrect invocation which writes something unexpectedly, which could not happen if you ran this with normal privileges" (from a comment on mist's answer by tripleee). The 2nd solution in viraptor's answer, find . 2>&1 | grep -v 'Permission denied' > some_file runs the risk of false positives (due to sending a mix of stdout and stderr through the pipeline), and, potentially, instead of reporting non-permission-denied errors via stderr, captures them alongside the output paths in the output file.

只需使用它在系统中搜索文件。

find / name YOUR_SEARCH_TERM 2>&1 | grep YOUR_SEARCH_TERM

我们不要做不必要的工程，你只是想搜索你的文件，对吧?然后，如果文件出现在您可访问的区域，该命令将为您列出文件。

这些错误被打印到标准错误输出(fd 2)。要过滤它们，只需将所有错误重定向到/dev/null:

find . 2>/dev/null > some_file

或者首先连接stderr和stdout，然后grep出那些特定的错误:

find . 2>&1 | grep -v 'Permission denied' > some_file

为了在整个文件系统中搜索某些文件，例如主机，除了会导致各种错误的/proc树，我使用以下方法:

# find / -path /proc ! -prune -o -name hosts -type f
/etc/hosts

注意:因为-prune始终为真，所以必须对其求反，以避免在输出中看到行/proc。我试过了!-readable方法，并发现它返回/proc下当前用户可以读取的所有内容。所以"OR"条件并不是你所期望的。

我从find手册页给出的示例开始，参见-prune选项。