重定向标准输出复制到从bash脚本本身的日志文件 [英] redirect COPY of stdout to log file from within bash script itself

问题描述

我知道如何标准输出重定向到一个文件：

  EXEC＆GT; foo.log
echo测试
 

这将会把'测试'到foo.log文件。

现在我想将输出重定向到日志文件，并保持它在stdout

即。它可以从平凡要做的脚本之外：

 脚本|三通foo.log
 

但我想从里面做

我试过

  EXEC |三通foo.log
 

但它没有工作。

解决方案

 ＃！的/ usr / bin中/ env的庆典＃重定向标准输出（大于）为命名管道（大于（））上运行的三通
EXEC＆GT; ＆GT;（TEE -i LOGFILE.TXT）＃如果没有这个，只有标准输出将被捕获 - 即你
＃日志文件中不含有任何错误消息。
＃看到（和给予好评），答案由亚当·斯皮尔，这使STDERR
＃作为一个单独的数据流 - 我不想简单地从他身上偷
＃加入他的回答我的。
EXEC 2  - ;＆放大器; 1回声富
回声酒吧＆GT;和2
 

请注意，这是庆典，而不是 SH 。如果调用与 SH myscript.sh 脚本，你会相处语法错误附近意外的标记线错误'＆GT; 。

如果您正在使用的信号陷阱时，您可能需要使用 T恤-i 选项，以避免在输出中断如果发生信号。 （感谢JamesThomasMoon1979的评论。）

---

工具的改变取决于他们是否写入到一个管道或终端的输出（ LS 用色彩和栏目化输出，例如）将检测上述结构的意义它们输出到管道

有选项来执行彩色化/ columnizing（例如 LS -C --color =总是）。请注意，这将导致颜色codeS被写入日志文件，以及，使得它的少的可读性。

I know how to redirect stdout to a file:

exec > foo.log
echo test

this will put the 'test' into the foo.log file.

Now I want to redirect the output into the log file AND keep it on stdout

i.e. it can be done trivially from outside the script:

script | tee foo.log

but I want to do it from the inside

I tried

exec | tee foo.log

but it didn't work

解决方案

#!/usr/bin/env bash

# Redirect stdout ( > ) into a named pipe ( >() ) running "tee"
exec > >(tee -i logfile.txt)

# Without this, only stdout would be captured - i.e. your
# log file would not contain any error messages.
# SEE (and upvote) the answer by Adam Spiers, which keeps STDERR
# as a seperate stream - I did not want to steal from him by simply
# adding his answer to mine.
exec 2>&1

echo "foo"
echo "bar" >&2

Note that this is bash, not sh. If you invoke the script with sh myscript.sh, you will get an error along the lines of syntax error near unexpected token '>'.

If you are working with signal traps, you might want to use the tee -i option to avoid disruption of the output if a signal occurs. (Thanks to JamesThomasMoon1979 for the comment.)

---

Tools that change their output depending on whether they write to a pipe or a terminal (ls using colors and columnized output, for example) will detect the above construct as meaning that they output to a pipe.

There are options to enforce the colorizing / columnizing (e.g. ls -C --color=always). Note that this will result in the color codes being written to the logfile as well, making it less readable.

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