Question

我的脚本遇到问题。我的变量未加1。我的循环遍历目录中的每个文件。

#!/bin/bash -x

files=0

find $PWD -type f -print0 | while IFS= read -r -d '' file; do
  files=$((files+1))
  echo "Files should be +1 now."
done

echo $files

结果：

+ files=0
+ IFS=
+ read -r -d '' file
+ find /home/home/Documents/sh -type f -print0
+ files=1
+ echo 'Files should be +1 now.'
Files should be +1 now.
+ IFS=
+ read -r -d '' file
+ files=2
+ echo 'Files should be +1 now.'
Files should be +1 now.
+ IFS=
+ read -r -d '' file
+ files=3
+ echo 'Files should be +1 now.'
Files should be +1 now.
+ IFS=
+ read -r -d '' file
+ echo 0
0

这是怎么回事？您可以在输出中清楚地看到files变量正在增加吗？那么它怎么仍然打印0？

编辑：我知道现在管道会创建一个新的子外壳，并且不会影响父子外壳。我该如何解决？

matches=0
find $workingDir -type f -print0 | while IFS= read -r -d '' filePath1; do
  find $workingDir -type f -print0 | while IFS= read -r -d '' filePath2; do


  # some calculation done on filepath1 and filepath 2
  # if calculation result is equal then increase matches + 1

  done
done

如何从双读循环内部操作变量？

0 个答案: