Shell脚本-迭代空格分隔的单词/字符（以zsh为单位）

我在理解如何在shell脚本中迭代空格分隔的单词/字符时遇到了一些困难。例如，我想迭代一个变量，该变量包含字母表中由空格分隔的字符

注意：即使字母表变量包含空格分隔的字符串而不是字符，即“aa bb cc…”而不是“a b c…”，结果也应相同

我尝试了以下提供的许多替代方案：

示例：

  local alphabet="a b c d e f g h i j k l m n o p q r s t u v w x y z"
  local index="0"
  for character in $alphabet; do
      index=$((++index))                                      
      echo "$index. $character"
      # Possibility to do some more stuff
  done 

1. a
2. b
3. c
and so on..

1. a b c d e f g h i j k l m n o p q r s t u v w x y z

  ####################################################################
  local alphabet="a b c d e f g h i j k l m n o p q r s t u v w x y z"
  local index="0"
  for character in ${alphabet[@]}; do
      index=$((++index))                                      
      echo "$index. $character"
      # Possibility to do some more stuff
  done 

  ####################################################################
  local alphabet="a b c d e f g h i j k l m n o p q r s t u v w x y z"                                            
  local alphabetArray=( ${alphabet} )                                                                             
  local index="0"                                                                                                 
  for character in "${alphabetArray[@]}"; do                                                                      
      index=$((++index))                                                                                          
      echo "$index. $character"                                                                                   
      # Possibility to do some more stuff                                                                                        
  done 

  ####################################################################
  local alphabet="a b c d e f g h i j k l m n o p q r s t u v w x y z"                                            
  local alphabetArray=( ${alphabet} )                                                                             
  local index="0"                                                                                                 
  for character in ${alphabetArray}; do                                                                           
      index=$((++index))                                                                                          
      echo "$index. $character"                                                                                   
      # Possibility to do some more stuff                                                                                        
  done

预期/期望输出：

  local alphabet="a b c d e f g h i j k l m n o p q r s t u v w x y z"
  local index="0"
  for character in $alphabet; do
      index=$((++index))                                      
      echo "$index. $character"
      # Possibility to do some more stuff
  done 

1. a
2. b
3. c
and so on..

1. a b c d e f g h i j k l m n o p q r s t u v w x y z

  ####################################################################
  local alphabet="a b c d e f g h i j k l m n o p q r s t u v w x y z"
  local index="0"
  for character in ${alphabet[@]}; do
      index=$((++index))                                      
      echo "$index. $character"
      # Possibility to do some more stuff
  done 

  ####################################################################
  local alphabet="a b c d e f g h i j k l m n o p q r s t u v w x y z"                                            
  local alphabetArray=( ${alphabet} )                                                                             
  local index="0"                                                                                                 
  for character in "${alphabetArray[@]}"; do                                                                      
      index=$((++index))                                                                                          
      echo "$index. $character"                                                                                   
      # Possibility to do some more stuff                                                                                        
  done 

  ####################################################################
  local alphabet="a b c d e f g h i j k l m n o p q r s t u v w x y z"                                            
  local alphabetArray=( ${alphabet} )                                                                             
  local index="0"                                                                                                 
  for character in ${alphabetArray}; do                                                                           
      index=$((++index))                                                                                          
      echo "$index. $character"                                                                                   
      # Possibility to do some more stuff                                                                                        
  done

结果：

  local alphabet="a b c d e f g h i j k l m n o p q r s t u v w x y z"
  local index="0"
  for character in $alphabet; do
      index=$((++index))                                      
      echo "$index. $character"
      # Possibility to do some more stuff
  done 

1. a
2. b
3. c
and so on..

1. a b c d e f g h i j k l m n o p q r s t u v w x y z

  ####################################################################
  local alphabet="a b c d e f g h i j k l m n o p q r s t u v w x y z"
  local index="0"
  for character in ${alphabet[@]}; do
      index=$((++index))                                      
      echo "$index. $character"
      # Possibility to do some more stuff
  done 

  ####################################################################
  local alphabet="a b c d e f g h i j k l m n o p q r s t u v w x y z"                                            
  local alphabetArray=( ${alphabet} )                                                                             
  local index="0"                                                                                                 
  for character in "${alphabetArray[@]}"; do                                                                      
      index=$((++index))                                                                                          
      echo "$index. $character"                                                                                   
      # Possibility to do some more stuff                                                                                        
  done 

  ####################################################################
  local alphabet="a b c d e f g h i j k l m n o p q r s t u v w x y z"                                            
  local alphabetArray=( ${alphabet} )                                                                             
  local index="0"                                                                                                 
  for character in ${alphabetArray}; do                                                                           
      index=$((++index))                                                                                          
      echo "$index. $character"                                                                                   
      # Possibility to do some more stuff                                                                                        
  done

附加测试（未成功）：

  local alphabet="a b c d e f g h i j k l m n o p q r s t u v w x y z"
  local index="0"
  for character in $alphabet; do
      index=$((++index))                                      
      echo "$index. $character"
      # Possibility to do some more stuff
  done 

1. a
2. b
3. c
and so on..

1. a b c d e f g h i j k l m n o p q r s t u v w x y z

  ####################################################################
  local alphabet="a b c d e f g h i j k l m n o p q r s t u v w x y z"
  local index="0"
  for character in ${alphabet[@]}; do
      index=$((++index))                                      
      echo "$index. $character"
      # Possibility to do some more stuff
  done 

  ####################################################################
  local alphabet="a b c d e f g h i j k l m n o p q r s t u v w x y z"                                            
  local alphabetArray=( ${alphabet} )                                                                             
  local index="0"                                                                                                 
  for character in "${alphabetArray[@]}"; do                                                                      
      index=$((++index))                                                                                          
      echo "$index. $character"                                                                                   
      # Possibility to do some more stuff                                                                                        
  done 

  ####################################################################
  local alphabet="a b c d e f g h i j k l m n o p q r s t u v w x y z"                                            
  local alphabetArray=( ${alphabet} )                                                                             
  local index="0"                                                                                                 
  for character in ${alphabetArray}; do                                                                           
      index=$((++index))                                                                                          
      echo "$index. $character"                                                                                   
      # Possibility to do some more stuff                                                                                        
  done

有人能提供一个解决方案来解决这个问题吗（我更喜欢迭代字母表变量而不显式使用索引变量的解决方案，例如$alphabet[index]）？

试试这个

IFS=$' \t\n'
local alphabet="a b c d e f g h i j k l m n o p q r s t u v w x y z"
local index="0"
for character in $alphabet; do
  index=$((++index))                                      
  echo "$index. $character"
  # Possibility to do some more stuff
done

---

希望能有所帮助

谢谢你的帮助。由于您的反馈，我发现了错误

当我发布这个问题时，我认为这是无关紧要的，但我正在试验.zshrc文件中的函数。因此，我使用（只是我的假设）zsh解释器，而不是sh或bash解释器

意识到这可能是一个潜在的问题，我在谷歌上搜索并发现了以下内容

因此，我测试了以下各项，并按预期工作：

  setopt shwordsplit                                                                                              
  local alphabet="a b c d e f g h i j k l m n o p q r s t u v w x y z"                                            
  local index="0"                                                                                                 
  for character in $alphabet; do                                                                                  
      index=$(($index+1))                                                                                         
      echo "$index. $character"                                                                                   
      # Possibility to do some more stuff                                                                                        
  done                                                                                                            
  unsetopt shwordsplit

注:

index=$((++$index))
and/or
index=$(($index++))

在zsh中似乎没有我预期的效果

。。。我本应使用的小细节：

((++index)) 
or
((index++))
instead of
index=$((++$index))

---

你的代码应该可以工作。唯一的原因是如果您将变量

IFS

设置为默认空白字符以外的其他字符，则不会出现此问题。我无法重现此问题。检查脚本中的

IFS

作业。我也不；一切正常，一切正常。无法重现该问题。@Barmar您是对的，我应该帮助他编写代码，而不是提供链接。IFS的默认值由空格字符组成（准确地说：空格、制表符和换行符）。除非Barmar说您的IFS不是空格、制表符或换行符，否则您的代码应该可以工作。请尝试打印IFS echo“$IFS”的值！谢谢你的建议，但是我针对我的特殊问题测试了它，但没有成功。