对于需要“管道”的情况，可以使用|&。

例如：

echo -ne "15\n100\n" | sort -c |& tee >sort_result.txt

or

TIMEFORMAT=%R;for i in `seq 1 20` ; do time kubectl get pods | grep node >>js.log ; done |& sort -h

这些基于Bash的解决方案可以分别处理标准输出和标准错误（从标准错误“sort-c”，或从标准错误到“sort-h”）。

以下函数可用于自动切换stdout/stderr和日志文件之间的输出。

#!/bin/bash

    #set -x

    # global vars
    OUTPUTS_REDIRECTED="false"
    LOGFILE=/dev/stdout

    # "private" function used by redirect_outputs_to_logfile()
    function save_standard_outputs {
        if [ "$OUTPUTS_REDIRECTED" == "true" ]; then
            echo "[ERROR]: ${FUNCNAME[0]}: Cannot save standard outputs because they have been redirected before"
            exit 1;
        fi
        exec 3>&1
        exec 4>&2

        trap restore_standard_outputs EXIT
    }

    # Params: $1 => logfile to write to
    function redirect_outputs_to_logfile {
        if [ "$OUTPUTS_REDIRECTED" == "true" ]; then
            echo "[ERROR]: ${FUNCNAME[0]}: Cannot redirect standard outputs because they have been redirected before"
            exit 1;
        fi
        LOGFILE=$1
        if [ -z "$LOGFILE" ]; then
            echo "[ERROR]: ${FUNCNAME[0]}: logfile empty [$LOGFILE]"

        fi
        if [ ! -f $LOGFILE ]; then
            touch $LOGFILE
        fi
        if [ ! -f $LOGFILE ]; then
            echo "[ERROR]: ${FUNCNAME[0]}: creating logfile [$LOGFILE]"
            exit 1
        fi

        save_standard_outputs

        exec 1>>${LOGFILE%.log}.log
        exec 2>&1
        OUTPUTS_REDIRECTED="true"
    }

    # "private" function used by save_standard_outputs() 
    function restore_standard_outputs {
        if [ "$OUTPUTS_REDIRECTED" == "false" ]; then
            echo "[ERROR]: ${FUNCNAME[0]}: Cannot restore standard outputs because they have NOT been redirected"
            exit 1;
        fi
        exec 1>&-   #closes FD 1 (logfile)
        exec 2>&-   #closes FD 2 (logfile)
        exec 2>&4   #restore stderr
        exec 1>&3   #restore stdout

        OUTPUTS_REDIRECTED="false"
    }

脚本内部用法示例：

echo "this goes to stdout"
redirect_outputs_to_logfile /tmp/one.log
echo "this goes to logfile"
restore_standard_outputs 
echo "this goes to stdout"

“最简单”的方法（仅限Bash 4）：

ls * 2>&- 1>&-

do_something 2>&1 | tee -a some_file

这会将标准错误重定向到标准输出，将标准输出重定向到some_file并将其打印到标准输出。

奇怪的是，这是有效的：

yourcommand &> filename

但这会产生语法错误：

yourcommand &>> filename
syntax error near unexpected token `>'

您必须使用：

yourcommand 1>> filename 2>&1

在考虑使用exec2>&1之类的情况下，如果可能的话，我发现使用如下Bash函数重写代码更容易阅读：

function myfunc(){
  [...]
}

myfunc &>mylog.log