如何将 stderr 重定向到文件？

Question

在 unix 中将标准错误描述符重定向到名为 error.txt 的文件所需的命令是什么？

到目前为止我有这个命令：

find / -name "report*" ________ error.txt

Answer 1

您可以像这样使用标准错误处理程序2：

find / -name "report*" 2>error.txt

看一个例子：

$ ls a1 a2
ls: cannot access a2: No such file or directory  <--- this is stderr
a1                                               <--- this is stdin
$ ls a1 a2 2>error.txt
a1
$ cat error.txt 
ls: cannot access a2: No such file or directory  <--- just stderr was stored

如BASH Shell: How To Redirect stderr To stdout ( redirect stderr to a File ) 中所述，这些是处理程序：

Handle	Name	Description
0	stdin	Standard input (stdin)
1	stdout	Standard output (stdout)
2	stderr	Standard error (stderr)

---

注意与&>error.txt 的区别，它同时重定向标准输入和标准错误（参见Redirect stderr and stdout in a bash script 或How to redirect both stdout and stderr to a file）：

$ ls a1 a2 &>error.txt
$ cat error.txt 
ls: cannot access a2: No such file or directory  <--- stdin and stderr
a1                                               <--- were stored