Question

我正在尝试使用另一个变量的值创建一个变量名。首先，我正在编写的其他可以起作用的代码示例：

#!/bin/bash
j=0
let "AVG_T_${j}"+="(${TEMPS[$j]})" #Works
let "tLen"="(${#AVG_T_0[@]})" #Works
tLen=${#AVG_T_0[@]} #Works
let "AVG_T_0=${AVG_T_0[@]:1}" #Works
let "AVG_T_${j}"="${AVG_T_0[@]:1}" #Works

这是我遇到的麻烦：

#!/bin/bash
j=0
"tLen"="(${#AVG_T_${j}[@]})" #Bad Substitution
let "AVG_T_${j}"="${AVG_T_${j}[@]:1}" #Bad Substitution

我不知道使它起作用的方法。我尝试了许多不同的语法，方括号，无等。我不知道从那里去哪里。

谢谢

这是我现在的位置。该代码应该检查温度区域的温度，然后给出电流输出和平均输出。

j=0
TEMPS=()
AVGtn=5
DIRECTORY="/sys/class/thermal/thermal_zone"${j}
while [ -d "$DIRECTORY" ];
do
    eval "AVG_T_${j}_TOTAL="""
    TEMPS+=($(cat $DIRECTORY/temp))
    TEMPS[$j]=$(convert ${TEMPS[$j]})
    eval "AVG_T_${j}+=(\"\${TEMPS[${j}]}\")"
    eval "tLen=\${#AVG_T_${j}[@]}" #Works
    if [ $tLen -gt $AVGtn ]; then
      eval "AVG_T_${j}=(\"\${AVG_T_${j}[@]:1}\")"
      eval "tLen=\${#AVG_T_${j}[@]}"
      AVG_T=()
      eval "AVG_T+=(\"\${AVG_T_${j}[@]}\")"
      for i in ${AVG_T[@]}; do
        let "AVG_T_${j}_TOTAL"+=${i}
       done
      eval "x=\${AVG_T_${j}_TOTAL}"
      let "AVG_TMP_${j}=(1000*($x/$tLen)+5)/1000"
    fi
    let "j++"
    DIRECTORY="/sys/class/thermal/thermal_zone"${j}
    sleep 3
done

这就是我最终得到的结果。我知道它可能会被收紧和清理，但是我很高兴拥有有效的代码。也许它将帮助像我这样的其他外行继续前进。

  j=0
  TEMPS=()
  DIRECTORY="/sys/class/thermal/thermal_zone"${j}
  while [ -d "$DIRECTORY" ];
    do
      # Put TOTAL to null
      eval "AVG_T_${j}_TOTAL="""
      # Add one directory temp to TEMPS
      TEMPS+=($(cat $DIRECTORY/temp))
      # Convert TEMP to Celsius
      TEMPS[$j]=$(convert ${TEMPS[$j]})
      # Put the converted TEMP into AVG_T_n
      eval "AVG_T_${j}+=(\"\${TEMPS[${j}]}\")"
      # Get the current Length of AVG_T_n
      eval "tLen=\${#AVG_T_${j}[@]}"
      # If the len of AVG_T_n is greater than AVGtn
      if [ $tLen -gt $AVGtn ]; then
        # Take Oldest temp out of Array
        eval "AVG_T_${j}=(\"\${AVG_T_${j}[@]:1}\")"
        # Reset tLen Length to the new length
        eval "tLen=\${#AVG_T_${j}[@]}"
      fi
      # Clear AVG_T
      AVG_T=()
      # Get an AVG_T_${j} duplicate duplicate from eval named AVG_T so we can use it as a condition that the for loop understands
      eval "AVG_T+=(\"\${AVG_T_${j}[@]}\")"
      # Add all of AVG_T values together and put into AVG_T_n_TOTAL
      for i in ${AVG_T[@]}; do
        let "AVG_T_${j}_TOTAL"+=${i}
      done
      # Ceate a variable with eval so that we can use it in the formula that provides the average temperature
      eval "x=\${AVG_T_${j}_TOTAL}"
      # Create the AVG_TMP_n
      eval let "AVG_TMP_${j}=\"(1000*(\$x/\$tLen)+5)/1000\""
      # Convert the AVG_TMP_n to Fahrenheit
      eval let "AVG_TMP_${j}f=\"\$(convertc2f AVG_TMP_${j})\""
      # Create another variable for echo for testing
      let "j++"
        DIRECTORY="/sys/class/thermal/thermal_zone"${j}
  done

Answer 1

我们可以使用eval。

#!/bin/bash
set -exu
declare -a AVG_T_0=(first second third fourth)

j=0
eval "tLen=\${#AVG_T_${j}[@]}"
eval "AVG_T_${j}=(\"\${AVG_T_${j}[@]:1}\")"
typeset -p tLen
typeset -p AVG_T_0
typeset -p "AVG_T_${j}"

替代失败

1 个答案: