• • 背景**

我终于修复了我的问题，有stdout & stderr屏幕和一个文件，加上有一个单独的文件的错误。Output stdout and stderr to file and screen and stderr to file in a limited environment

• • 问题**

问题在于行的顺序。
有时候是可以的：

FIRST
ERROR
LAST
ERROR2
LAST2

有时错误出现在末尾：

FIRST
LAST
LAST2
ERROR
ERROR2

我不知道为什么（除了下面可能有一个信号量...但是...不确定。如果是这样的话，除了给每个回显添加行号之外，没有解决方案）。

• • 出现问题的代码部分**

{ "$0" "${mainArgs[@]}" 2>&1 1>&3 | tee -a "$logPath/$logFileName.err" 1>&3 ; } 3>&1 | tee -a "$logPath/$logFileName.log" &

• • 完整的可测试代码**

m=0
declare -a mainArgs
if [ ! "$#" = "0" ]; then
    for arg in "$@"; do
        mainArgs[$m]=$arg
        m=$(($m + 1))
    done
fi

function containsElement()
# $1 string to find
# $2 array to search in
# return 0 if there is a match, otherwise 1
{
  local e match="$1"
  shift
  for e; do [[ "$e" == "$match" ]] && return 0; done
  return 1
}

function hasMainArg()
# $1 string to find
# return 0 if there is a match, otherwise 1
{
    local match="$1"
    containsElement "$1" "${mainArgs[@]}"
    return $?
}

function activateLogs()
# $1 = logOutput: What is the output for logs: SCREEN, DISK, BOTH. Default is DISK. Optional parameter.
{
    local logOutput=$1
    if [ "$logOutput" != "SCREEN" ] && [ "$logOutput" != "BOTH" ]; then
        logOutput="DISK"
    fi
    
    if [ "$logOutput" = "SCREEN" ]; then
        echo "Logs will only be output to screen"
        return
    fi
    
    hasMainArg "--force-log"
    local forceLog=$?
        
    local isFileDescriptor3Exist=$(command 2>/dev/null >&3 && echo "Y")
    
    if [ "$isFileDescriptor3Exist" = "Y" ]; then
        echo "Logs are configured"
    elif [ "$forceLog" = "1" ] && ([ ! -t 1 ] || [ ! -t 2 ]); then
        # Use external file descriptor if they are set except if having "--force-log"
        echo "Logs are configured externally"
    else
        echo "Relaunching with logs files"
        local logPath="logs"
        if [ ! -d $logPath ]; then mkdir $logPath; fi
        
        local logFileName=$(basename "$0")"."$(date +%Y-%m-%d.%k-%M-%S)
    
        exec 4<> "$logPath/$logFileName.log" # File descriptor created only to get the underlying file in any output option
        if [ "$logOutput" = "DISK" ]; then
            # FROM: https://stackoverflow.com/a/45426547/214898
            exec 3<> "$logPath/$logFileName.log"
            "$0" "${mainArgs[@]}" 2>&1 1>&3 | tee -a "$logPath/$logFileName.err" 1>&3 &
        else
            # FROM: https://stackoverflow.com/a/70790574/214898
            { "$0" "${mainArgs[@]}" 2>&1 1>&3 | tee -a "$logPath/$logFileName.err" 1>&3 ; } 3>&1 | tee -a "$logPath/$logFileName.log" &
        fi
        
        exit        
    fi
}

#activateLogs "DISK"
#activateLogs "SCREEN"
activateLogs "BOTH"

echo "FIRST"
echo "ERROR" >&2
echo "LAST"
echo "ERROR2" >&2
echo "LAST2"