Re: bin/57253: xargs wraps lines after ~4k characters

[Marc Daniel Fege <marc%fege.net@localhost>]

The following reply was made to PR bin/57253; it has been noted by GNATS.

From: Marc Daniel Fege <marc%fege.net@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: bin/57253: xargs wraps lines after ~4k characters
Date: Thu, 02 Mar 2023 12:44:41 +0100

 Hello again RVP
 
 >  Well, most Unix systems have _some_ kind of limit on ARG_MAX. On
 >  Linux it is around 1MB; on FreeBSD it is ~512KB; on NetBSD/amd64
 >  it is:
 >=20
 >  $ sysctl -n kern.argmax
 >  262144
 >  $
 >=20
 >  so, that's more that 4KB. And, as long as xargs doesn't _insert_
 >  a space where there should be none, it's behaving according to
 >  specs:
 
 Indeed, some limit will be there anyway. But do those limits need to be=20
 (artificially) defined in the userland programs themselves to handle an=20
 otherwise comming up exception of the programming language or library? I me=
 an,=20
 the boundries between shells and tools have been pushed multiple times whic=
 h I=20
 clearly see in the last 20+ years. So why not again at least push those lim=
 its=20
 to the technical/architecture maximum and equalize them out? Some "quality =
 of=20
 life" improvement does not harm.
 
 Kind regars
 =2D Marc.
 
 Am Donnerstag, 2. M=E4rz 2023, 12:25:01 CET schrieben Sie:
 > The following reply was made to PR bin/57253; it has been noted by GNATS.
 >=20
 > From: RVP <rvp%SDF.ORG@localhost>
 > To: gnats-bugs%netbsd.org@localhost
 > Cc:
 > Subject: Re: bin/57253: xargs wraps lines after ~4k characters
 > Date: Thu, 2 Mar 2023 11:22:48 +0000 (UTC)
 >=20
 >  On Thu, 2 Mar 2023, marc%fege.net@localhost wrote:
 >  > I have some very long output lines in various shell scripts needed
 >  > to be processed by xargs.
 >  > [...] As long as there is addressable memory available, no
 >  > command should forcefully ever wrap after a certain amount of line
 >  > length or stop working on an artificially limit set, even if this
 >  > limit had a reason in former times.
 >=20
 >  Well, most Unix systems have _some_ kind of limit on ARG_MAX. On
 >  Linux it is around 1MB; on FreeBSD it is ~512KB; on NetBSD/amd64
 >  it is:
 >=20
 >  $ sysctl -n kern.argmax
 >  262144
 >  $
 >=20
 >  so, that's more that 4KB. And, as long as xargs doesn't _insert_
 >  a space where there should be none, it's behaving according to
 >  specs:
 >=20
 >  ```
 >  $ cat a.awk
 >  #!/usr/bin/awk -f
 >=20
 >  BEGIN {
 >           cmd =3D "sysctl -n kern.argmax"
 >           cmd | getline MAX
 >           close(cmd)
 >           for (i =3D 0; i < MAX * 5; i +=3D length(s)) {
 >                   s =3D s "a"
 >                   print s
 >           }
 >  }
 >  $ chmod u+x a.awk
 >  $ ./a.awk > 1
 >  $ ./a.awk | xargs printf '%s\n' > 2
 >  $ cmp 1 2 && echo OK
 >  OK
 >  $
 >  ```
 >=20
 >  -RVP