shell - How to regroup commands in a shell to avoid repeated redirections?

Question

I have a script where I output three things into a file. I'd like to call the > operator only once. Is there a way to describe a block of instructions? Should I use a function?

#!/bin/sh

for i in $(ls src)
 do
  f=${i%.*}
  echo 'first bit' > dist/$i.htm
  perl myScriptThatOutputsSecondBit.pl >> dist/$i.htm
  echo 'third bit' >> dist/$i.htm
 done

Answer 1

使用compound/group命令：

要在当前 shell 中运行它，

 {echo 'first bit';perl myScriptThatOutputsSecondBit.pl;echo 'third bit';} > dist/$i.htm 

要在子 shell 中运行它，

 (echo 'first bit';perl myScriptThatOutputsSecondBit.pl;echo 'third bit') > dist/$i.htm 

Answer 2

写一个简单的日志函数，这样会更有效率。例如

log(){
   echo $1 >> dist/$i.htm
}

然后从脚本中调用它：

for i in $(ls src)
do
    f=${i%.*}
    log 'first bit'
    perl myScriptThatOutputsSecondBit.pl >> dist/$i.htm
    log 'third bit'
done