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在哪里可以找到 bash 中 for 循环的手册

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在哪里可以找到 bash 中 for 循环的手册

我忘记了 bash 循环的语法和语义for，并尝试在系统中查找手册。我找不到它。它不在man bash或中man builtins。我在哪里可以快速本地参考bash命令？

答案1

也许您需要比手册页更多的细节。以下是一些示例

从man bash：

   for name [ in word ] ; do list ; done
          The list of words following in is expanded, generating a list of
          items.  The variable name is set to each element of this list in
          turn,  and  list is executed each time.  If the in word is omit‐
          ted, the for command executes  list  once  for  each  positional
          parameter that is set (see PARAMETERS below).  The return status
          is the exit status of the last command that  executes.   If  the
          expansion of the items following in results in an empty list, no
          commands are executed, and the return status is 0.

   for (( expr1 ; expr2 ; expr3 )) ; do list ; done
          First, the arithmetic expression expr1 is evaluated according to
          the  rules  described  below  under  ARITHMETIC EVALUATION.  The
          arithmetic expression expr2 is then evaluated  repeatedly  until
          it  evaluates  to zero.  Each time expr2 evaluates to a non-zero
          value, list is executed and the arithmetic expression  expr3  is
          evaluated.   If  any  expression is omitted, it behaves as if it
          evaluates to 1.  The return value is the exit status of the last
          command in list that is executed, or false if any of the expres‐
          sions is invalid.

例子：

for i in *.txt;do echo textfiles: $i;done

for (( i=1; i<=20 ; i++ )) ; do echo $i;done

for i in *.TXT;do mv $i ${i/\.TXT/}.txt; done  # "move *.TXT *.txt"

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