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Comment by RexRollman | Hacker News Reader

Bah! Give me Ksh.

I much prefer ksh myself, in particular for scripting. Fun fact about how bash is broken:

  export a=0
  cat $file | while read line
  do
    a=$(expr $a + 1)
  done

Bash will fork the while loop as a separate process, inheriting (copying) its own environment, and the variable will only update locally, not in the parent process.

I thought every shell that is sh compatible would fork a while, and a for loop, as a matter of fact any loop into a sepearate process.

This comment however reminds me of some behaviour of bash 2.03 or earlier, where this behaviour was flawed, if you suddenly changed execution path during a recursion in a shell script. Sorry I can't describe it better, and that bash version, that was before 2.03 is long gone now!

Isn't the issue the pipe, not while?

  export a=0
  while read line ; do
    a=$(expr $a + 1)
  done < $file
  echo $a

(Some old shells fork on < but bash isn't one of them).

I think the pipe was the issue.

Nice to know that bash doesn't fork loops that are being used with redirection, and not piping!

save a kitten =)

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