[OT] Scripting question: the length limit of a list?

On Thu, Nov 01, 2007 at 01:49:03PM -0700, Mike Bird wrote:

> On Thursday 01 November 2007 13:07, Wei Chen wrote:
> > I would like to write a bash script like the following one:
> >
> > for i in `some program that outputs a word list`
> > do
> > echo $i
> > done
> >
> > where the word list can be very very long. I wonder what is the upper bound
> > limit of the length of word lists in "for" loop of a bash script, or
> > does it only
> > depend on the hardware (say, RAM)? Thank you in advance.
>
> Assuming that the words are output one per line, something
> like the following can handle lists of any size:
>
> some program | while read i; do echo $i; done

A wild thought, but if you want to count the words in the output can you
not pipe it to wc? I haven't tried, this is just a thought...

--
richard

--

On 11/01/07 15:07, Wei Chen wrote:
> Hi,
>
> I would like to write a bash script like the following one:
>
> for i in `some program that outputs a word list`
> do
> echo $i
> done
>
> where the word list can be very very long. I wonder what is the upper bound
> limit of the length of word lists in "for" loop of a bash script, or
> does it only
> depend on the hardware (say, RAM)? Thank you in advance.

I *think* that bash has a 128KB buffer limit.

--
Ron Johnson, Jr.
Jefferson LA USA

Give a man a fish, and he eats for a day.
Hit him with a fish, and he goes away for good!

--

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Mike Bird wrote:
> On Thursday 01 November 2007 13:07, Wei Chen wrote:
>> I would like to write a bash script like the following one:
>>
>> for i in `some program that outputs a word list`
>> do
>> echo $i
>> done
>>
>> where the word list can be very very long. I wonder what is the upper bound
>> limit of the length of word lists in "for" loop of a bash script, or
>> does it only
>> depend on the hardware (say, RAM)? Thank you in advance.
>
> Assuming that the words are output one per line, something
> like the following can handle lists of any size:
>
> some program | while read i; do echo $i; done
>

Thanks for all the replies. I think the method of piping ``while read''
can be a good replacement. I have changed my script accordingly. Thank you.

- --
Cheers,

Wei Chen
http://www.acplex.com/people/wchen/
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