GNU bug report logs - #23190
wc - Different output

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Seva Adari <oddissyus <at> gmail.com>
To: bug-coreutils <at> gnu.org
Subject: wc - Different output
Date: Fri, 1 Apr 2016 18:02:00 -0400

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Hello,

I am not sure if this a bug or expected behavior! Here is different output
from each run variation of wc invocation:
    wc -l test.txt                                         Output: 20
    awk '{print $0}' /tmp/test.txt | wc -l       Output: 21
    cut /tmp/test.txt -f1 | wc -l                    Output: 21

Similarly, when I read file from a python program I get 21 line count.

File, test.txt (attached here with) could be missing last "new line".

Thanks
Seva

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[test.txt.gz (application/x-gzip, attachment)]

Message #8 received at 23190 <at> debbugs.gnu.org (full text, mbox):

From: Assaf Gordon <assafgordon <at> gmail.com>
To: Seva Adari <oddissyus <at> gmail.com>, 23190 <at> debbugs.gnu.org
Subject: Re: bug#23190: wc - Different output
Date: Sat, 2 Apr 2016 16:40:00 -0400

tags 23190 notabug
close 23190
thanks

Hello Seva,

On 04/01/2016 06:02 PM, Seva Adari wrote:
> I am not sure if this a bug or expected behavior! Here is different output
> from each run variation of wc invocation:
>      wc -l test.txt                                         Output: 20
>      awk '{print $0}' /tmp/test.txt | wc -l       Output: 21
>      cut /tmp/test.txt -f1 | wc -l                    Output: 21
[...]
>
> File, test.txt (attached here with) could be missing last "new line".

This is not a bug in 'wc', but the way it works (perhaps not intuitively):

'wc' does not count conceptual lines but the number of newline characters in the file.
Since the last file does not have a newline character (ASCII 0x10) - it is not counted.

The following will demonstrate:

   $ printf "hello" | wc -l
   0
   $ printf "hello\n" | wc -l
   1
   $ printf "a\nb\nc" | wc -l
   2

And 'awk' indeed automatically adds a newline when using 'print', like so:

   $ printf "a\nb\nc" | awk '{print $0}' | wc -l
   3


I'm therefore closing the bug, but discussion can continue by replying to this thread.

regards,
 - assaf

Message #11 received at 23190 <at> debbugs.gnu.org (full text, mbox):

From: Seva Adari <oddissyus <at> gmail.com>
To: Assaf Gordon <assafgordon <at> gmail.com>
Cc: 23190 <at> debbugs.gnu.org
Subject: Re: bug#23190: wc - Different output
Date: Thu, 7 Apr 2016 17:21:05 -0400

[Message part 1 (text/plain, inline)]

Thanks for the explanation!

On Sat, Apr 2, 2016 at 4:40 PM, Assaf Gordon <assafgordon <at> gmail.com> wrote:

> tags 23190 notabug
> close 23190
> thanks
>
> Hello Seva,
>
> On 04/01/2016 06:02 PM, Seva Adari wrote:
>
>> I am not sure if this a bug or expected behavior! Here is different output
>> from each run variation of wc invocation:
>>      wc -l test.txt                                         Output: 20
>>      awk '{print $0}' /tmp/test.txt | wc -l       Output: 21
>>      cut /tmp/test.txt -f1 | wc -l                    Output: 21
>>
> [...]
>
>>
>> File, test.txt (attached here with) could be missing last "new line".
>>
>
> This is not a bug in 'wc', but the way it works (perhaps not intuitively):
>
> 'wc' does not count conceptual lines but the number of newline characters
> in the file.
> Since the last file does not have a newline character (ASCII 0x10) - it is
> not counted.
>
> The following will demonstrate:
>
>    $ printf "hello" | wc -l
>    0
>    $ printf "hello\n" | wc -l
>    1
>    $ printf "a\nb\nc" | wc -l
>    2
>
> And 'awk' indeed automatically adds a newline when using 'print', like so:
>
>    $ printf "a\nb\nc" | awk '{print $0}' | wc -l
>    3
>
>
> I'm therefore closing the bug, but discussion can continue by replying to
> this thread.
>
> regards,
>  - assaf
>
>

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