[9fans] trailing newline in awk

[9fans] trailing newline in awk

[dexen deVries]

hi list,

can't wrap my head around this: in an awk script, how to take some action if a 
file lacks last trailing Line Feed?

i want to modify files with contents like:
text LF
text LF
text

and leave undisturbed files with content like:
text LF
text LF
text LF

in other words, i want to either:
 - match line that is empty and is last line of file (awk doesn't seem to take 
any action on such line), or, alternatively,
 - match a line that is last line of file and lacks terminating LF.

-- 
dexen deVries

[[[↓][→]]]

Already many of the mutants disguised as human beings are walking the streets 
of Earth's cities.
 -- Music Instructor, ``Electro City''

Re: [9fans] trailing newline in awk

[hugo rivera]

Seems impossible to do in awk, but I could be wrong. In ssam is easy:

% ssam -ne 'y/.+\n/p' file

prints the last line if it's missing the line feed.

2012/1/26 dexen deVries <dexen.devries@gmail.com>:
> hi list,
>
> can't wrap my head around this: in an awk script, how to take some action if a
> file lacks last trailing Line Feed?
>
> i want to modify files with contents like:
> text LF
> text LF
> text
>
> and leave undisturbed files with content like:
> text LF
> text LF
> text LF
>
> in other words, i want to either:
>  - match line that is empty and is last line of file (awk doesn't seem to take
> any action on such line), or, alternatively,
>  - match a line that is last line of file and lacks terminating LF.
>
> --
> dexen deVries
>
> [[[↓][→]]]
>
> Already many of the mutants disguised as human beings are walking the streets
> of Earth's cities.
>  -- Music Instructor, ``Electro City''
>



-- 
Hugo

Re: [9fans] trailing newline in awk

[Steve Simon]

Interesting one.

Both sed and awk has treat EOF as a line terminator
so either of these will work:

	awk '{print}' junk
	sed '' junk

but sam doesn't seem to regard a line without a newline as
having an end, so its not simple here:

	{ echo ',x/$?\n/ c/\n/' ; echo '1,$p' } | sam -d junk >[2] /dev/null

-Steve

Re: [9fans] trailing newline in awk

[Jonathan Cast]

On Thu, 2012-01-26 at 13:15 +0100, dexen deVries wrote:
> hi list,
>
> can't wrap my head around this: in an awk script, how to take some action if a
> file lacks last trailing Line Feed?
>
> i want to modify files with contents like:
> text LF
> text LF
> text
>
> and leave undisturbed files with content like:
> text LF
> text LF
> text LF

If this is all you're trying to do,

    awk 1 file

works, no?

jcc