What's the perl command corresponding to the following awk code:

$ awk '{sub(/[0-9]+$/, $NF+1); print}' file

Regards,
HZ

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

In comp.lang.perl.misc, Hongyi Zhao <hongyi.zhao@gmail.com> wrote:

What's the perl command corresponding to the following awk code:

$ awk '{sub(/[0-9]+$/, $NF+1); print}' file

That finds an all numerical field at the end of a line and adds one
to it.

$ cat file
0
a1
aa 2
aaa 3 4
bbb
ccc -2
$ perl -wpe 's/\b[0-9]+$/$&+1/e' file
0
a1
aa 2
aaa 3 4
bbb
ccc -3
$
$ awk '{sub(/[0-9]+$/, $NF+1); print}' file
1
a1
aa 3
aaa 3 5
bbb
ccc --1
$

Ugh, yikes. That last line.

Some more test cases.

$ cat file
0
a1
aa 2
aaa 3 4
bbb
-0
01
-1
abc -2
cba --3
cab ---4
bac ----5
acb -----6
$ awk '{sub(/[0-9]+$/, $NF+1); print}' < /tmp/file
1
a1
aa 3
aaa 3 5
bbb
-1
2
-0
abc --1
cba --1
cab ---1
bac ----1
acb -----1
$

Okay, I give up. I can't explain the abc verus cba lines without a bunch
of hard coded rules. Someone else who understands what awk is doing may
have better luck.

Eiijah
------
never used awk much before starting perl

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

Am 23.09.2021 um 03:40 schrieb Hongyi Zhao:

What's the perl command corresponding to the following awk code:

$ awk '{sub(/[0-9]+$/, $NF+1); print}' file

Regards,
HZ

a2p meint dazu:

af@pi3:~ $ echo '{sub(/[0-9]+$/, $NF+1); print}' | a2p
#!/usr/bin/perl
eval 'exec /usr/bin/perl -S $0 ${1+"$@"}'
if $running_under_some_shell;
# this emulates #! processing on NIH machines.
# (remove #! line above if indigestible)

eval '$'.$1.'$2;' while $ARGV[0] =~ /^([A-Za-z_0-9]+=)(.*)/ && shift;
# process any FOO=bar switches

$, = ' '; # set output field separator
$\ = "\n"; # set output record separator

while (<>) {
chomp; # strip record separator
@Fld = split(' ', $_, -1);
($s_ = '"'.($Fld[($#Fld+1)] + 1).'"') =~ s/&/\$&/g, s/[0-9]+$/eval
$s_/e;
print $_;
}
af@pi3:~ $



Andreas

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On Thursday, September 23, 2021 at 1:23:02 PM UTC+8, Andreas Fenner wrote:

Am 23.09.2021 um 03:40 schrieb Hongyi Zhao:

What's the perl command corresponding to the following awk code:

$ awk '{sub(/[0-9]+$/, $NF+1); print}' file

Regards,
HZ

a2p meint dazu:

af@pi3:~ $ echo '{sub(/[0-9]+$/, $NF+1); print}' | a2p
#!/usr/bin/perl
eval 'exec /usr/bin/perl -S $0 ${1+"$@"}'
if $running_under_some_shell;
# this emulates #! processing on NIH machines.
# (remove #! line above if indigestible)

eval '$'.$1.'$2;' while $ARGV[0] =~ /^([A-Za-z_0-9]+=)(.*)/ && shift;
# process any FOO=bar switches

$, = ' '; # set output field separator
$\ = "\n"; # set output record separator

while (<>) {
chomp; # strip record separator
@Fld = split(' ', $_, -1);
($s_ = '"'.($Fld[($#Fld+1)] + 1).'"') =~ s/&/\$&/g, s/[0-9]+$/eval
$s_/e;
print $_;
}
af@pi3:~ $

Thank you so much for letting me know about this tool

HZ

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

In comp.lang.perl.misc, Andreas Fenner <Andis_Spamtonne@web.de> wrote:

a2p meint dazu:

af@pi3:~ $ echo '{sub(/[0-9]+$/, $NF+1); print}' | a2p
#!/usr/bin/perl
eval 'exec /usr/bin/perl -S $0 ${1+"$@"}'
if $running_under_some_shell;
# this emulates #! processing on NIH machines.
# (remove #! line above if indigestible)

eval '$'.$1.'$2;' while $ARGV[0] =~ /^([A-Za-z_0-9]+=)(.*)/ && shift;
# process any FOO=bar switches

$, = ' '; # set output field separator
$\ = "\n"; # set output record separator

while (<>) {
chomp; # strip record separator
@Fld = split(' ', $_, -1);
($s_ = '"'.($Fld[($#Fld+1)] + 1).'"') =~ s/&/\$&/g, s/[0-9]+$/eval $s_/e;
print $_;
}
af@pi3:~ $

Nice, but not 100% compatible.

Your script is in /tmp/pa (for perled-awk), my test file from yesterday
is in /tmp/file; here's a comparison of output:

$ perl /tmp/pa < /tmp/file > /tmp/file.pa
$ awk '{sub(/[0-9]+$/, $NF+1); print}' < /tmp/file > /tmp/file.awk
$ diff /tmp/file.pa /tmp/file.awk
3,4c3,4
< aa 1
< aaa 3 1
---

aa 3
aaa 3 5

6,8c6,8
< ccc -1
< -1
< abc -1
---

ccc --1
-0
abc --1

$

AWK does something odd with /-+[0-9]+/ "numbers".

Elijah
------
does not understand what AWK is doing

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

with <eli$2109231453@qaz.wtf> Eli the Bearded wrote:

In comp.lang.perl.misc, Andreas Fenner <Andis_Spamtonne@web.de> wrote:

a2p meint dazu:

Probably not that compatible.

*SKIP*

AWK does something odd with /-+[0-9]+/ "numbers".

(~/foo.4AI0R3.test is your last test-file) This suggests, that "$NF"
isn't actually "number of fields in the current record". It actually
some weird pointer to the last field in the record and then The Number
of Fields can be somehow derived from it. And it evaluates accordingly:

% awk '{print $NF, $NF + 1 }' ~/foo.4AI0R3.test
0 1
a1 1
2 3
4 5
bbb 1
-0 1
01 2
-1 0
-2 -1
--3 1
---4 1
----5 1
-----6 1

I'm glad I have perl to get number of fields.

*CUT*

--
Torvalds' goal for Linux is very simple: World Domination
Stallman's goal for GNU is even simpler: Freedom

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

Eric Pozharski <whynot@pozharski.name> writes:

This suggests, that "$NF" isn't actually "number of fields in the
current record".

The man page says NF, not $NF:
The variable NF is set to the total number of fields in the input record.

It actually some weird pointer to the last field in the record

Yes and no, that is, the weird part :-)

% awk '{print $NF, $NF + 1 }' ~/foo.4AI0R3.test

Try this:

awk '{print NF, $NF, $NF + 1 }' ~/foo.4AI0R3.test

and then it may become clear what awk is doing.

-- HASM

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

Eric Pozharski <whynot@pozharski.name> writes:

with <eli$2109231453@qaz.wtf> Eli the Bearded wrote:

In comp.lang.perl.misc, Andreas Fenner <Andis_Spamtonne@web.de> wrote:

a2p meint dazu:

Probably not that compatible.

*SKIP*

AWK does something odd with /-+[0-9]+/ "numbers".

(~/foo.4AI0R3.test is your last test-file) This suggests, that "$NF"
isn't actually "number of fields in the current record". It actually
some weird pointer to the last field in the record and then The Number
of Fields can be somehow derived from it. And it evaluates accordingly:

% awk '{print $NF, $NF + 1 }' ~/foo.4AI0R3.test
0 1
a1 1
2 3
4 5
bbb 1
-0 1
01 2
-1 0
-2 -1
--3 1
---4 1
----5 1
-----6 1

I'm glad I have perl to get number of fields.

*CUT*

NF is an Awk variable that represents the number of fields.

$0 is the current line. $1, $2, $3, ... are the first, second, third,
... fields.

If there are 3 fields, the NF is 1, and $NF is equivalent to $3 -- i.e.,
$NF is the last field.

Awk variable names are identifiers; there are no Perl-like sigils. The
'$' prefix is used only with the numbered fields of the current line.
The way that $NF expands to $3 and then to the text of the third field
is a little surprising if you're accustomed to Perl and/or Bourne-like
shells.

One way to think of it is that $ is an operator that takes an integer expression operand and yields a reference to a field (or to the entire
line if the operand is zero).

$ echo 100 200 300 | awk '{print NF}'
3
$ echo 100 200 300 | awk '{print $NF}'
300
$ echo 100 200 300 | awk '{print $NF-1}'
299
$ echo 100 200 300 | awk '{print $(NF-1)}'
200
$ echo 100 200 300 | awk '{print $(NF-2)}'
100
$ echo 100 200 300 | awk '{print $(NF-3)}'
100 200 300

And you can have white space between the $ and its operand.

The GNU Awk manual doesn't *quite* say that $ is an operator, but it
does discuss how you can use it with a non-constant field number.

https://www.gnu.org/software/gawk/manual/html_node/Nonconstant-Fields.html

--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for Philips
void Void(void) { Void(); } /* The recursive call of the void */

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

with <87mto1lr4r.fsf@nosuchdomain.example.com> Keith Thompson wrote:

Eric Pozharski <whynot@pozharski.name> writes:

with <eli$2109231453@qaz.wtf> Eli the Bearded wrote:

In comp.lang.perl.misc, Andreas Fenner <Andis_Spamtonne@web.de>
wrote:

*SKIP*

Awk variable names are identifiers; there are no Perl-like sigils.
The '$' prefix is used only with the numbered fields of the current
line. The way that $NF expands to $3 and then to the text of the
third field is a little surprising if you're accustomed to Perl and/or Bourne-like shells.

That's my understanding of this syntax now too. Just checked,
unfortunately...

*SKIP*

The GNU Awk manual doesn't *quite* say that $ is an operator, but it
does discuss how you can use it with a non-constant field number. https://www.gnu.org/software/gawk/manual/html_node/Nonconstant-Fields.html

This sacred knowledge is of no use to me ('awk' of 'busybox' even fails
to evaluate NR (looks like it always 1)). Pity (I observe some activity
up there, but I'm glad my expectations are already downgraded).

--
Torvalds' goal for Linux is very simple: World Domination
Stallman's goal for GNU is even simpler: Freedom

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

Eric Pozharski <whynot@pozharski.name> writes:

with <87mto1lr4r.fsf@nosuchdomain.example.com> Keith Thompson wrote:

Eric Pozharski <whynot@pozharski.name> writes:

with <eli$2109231453@qaz.wtf> Eli the Bearded wrote:

In comp.lang.perl.misc, Andreas Fenner <Andis_Spamtonne@web.de>
wrote:

*SKIP*

Awk variable names are identifiers; there are no Perl-like sigils.
The '$' prefix is used only with the numbered fields of the current
line. The way that $NF expands to $3 and then to the text of the
third field is a little surprising if you're accustomed to Perl and/or
Bourne-like shells.

That's my understanding of this syntax now too. Just checked, unfortunately...

*SKIP*

The GNU Awk manual doesn't *quite* say that $ is an operator, but it
does discuss how you can use it with a non-constant field number.
https://www.gnu.org/software/gawk/manual/html_node/Nonconstant-Fields.html

This sacred knowledge is of no use to me ('awk' of 'busybox' even fails
to evaluate NR (looks like it always 1)). Pity (I observe some activity
up there, but I'm glad my expectations are already downgraded).

Really? I have busybox 1.30.1 on Ubuntu, and it works for me.

$ printf 'line one\nline two\nline three\n' | busybox awk '{print NR, $0}'
1 line one
2 line two
3 line three
$ echo one two three | busybox awk '{print NF, $NF, $(NF-1)}'
3 three two
$

--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for Philips
void Void(void) { Void(); } /* The recursive call of the void */

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

with <87ee9claxk.fsf@nosuchdomain.example.com> Keith Thompson wrote:

Eric Pozharski <whynot@pozharski.name> writes:

with <87mto1lr4r.fsf@nosuchdomain.example.com> Keith Thompson wrote:

Eric Pozharski <whynot@pozharski.name> writes:

with <eli$2109231453@qaz.wtf> Eli the Bearded wrote:

In comp.lang.perl.misc, Andreas Fenner <Andis_Spamtonne@web.de>
wrote:

*SKIP*

This sacred knowledge is of no use to me ('awk' of 'busybox' even
fails to evaluate NR (looks like it always 1)). Pity (I observe some
activity up there, but I'm glad my expectations are already
downgraded).

Really? I have busybox 1.30.1 on Ubuntu, and it works for me.

Well, 1.31.1 on android doesn't (forced upgrade right now) (also, there
are multiple builds of busybox). But I understand, there might be
differences what build-time decisiions have been made (also, dying off
is an issue too). When time will come somehow will make it through with
what I've got.

*CUT*

--
Torvalds' goal for Linux is very simple: World Domination
Stallman's goal for GNU is even simpler: Freedom

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

Eric Pozharski <whynot@pozharski.name> writes:

with <87ee9claxk.fsf@nosuchdomain.example.com> Keith Thompson wrote:

Eric Pozharski <whynot@pozharski.name> writes:

with <87mto1lr4r.fsf@nosuchdomain.example.com> Keith Thompson wrote:

Eric Pozharski <whynot@pozharski.name> writes:

with <eli$2109231453@qaz.wtf> Eli the Bearded wrote:

In comp.lang.perl.misc, Andreas Fenner <Andis_Spamtonne@web.de>
wrote:

*SKIP*

This sacred knowledge is of no use to me ('awk' of 'busybox' even
fails to evaluate NR (looks like it always 1)). Pity (I observe some
activity up there, but I'm glad my expectations are already
downgraded).

Really? I have busybox 1.30.1 on Ubuntu, and it works for me.

Well, 1.31.1 on android doesn't (forced upgrade right now) (also, there
are multiple builds of busybox). But I understand, there might be differences what build-time decisiions have been made (also, dying off
is an issue too). When time will come somehow will make it through with
what I've got.

*CUT*

That's surprising. I don't see anything in the busybox awk.c that
tells me it's even possible to disable support for NR. Can you
confirm that the output of this:

( echo line 1 ; echo line 2 ) | awk '{print NR}'

(or use "busybox awk" if necessary) *isn't*

1
2

? If so, let's continue this on comp.lang.awk. (I haven't cross-posted
or redirected followups yet; I don't want to start a new discussion in a different newsgroup unless there's something to discuss.)

--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for Philips
void Void(void) { Void(); } /* The recursive call of the void */

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

with <87k0j2kj70.fsf@nosuchdomain.example.com> Keith Thompson wrote:

Eric Pozharski <whynot@pozharski.name> writes:

with <87ee9claxk.fsf@nosuchdomain.example.com> Keith Thompson wrote:

Eric Pozharski <whynot@pozharski.name> writes:

with <87mto1lr4r.fsf@nosuchdomain.example.com> Keith Thompson wrote:

Eric Pozharski <whynot@pozharski.name> writes:

with <eli$2109231453@qaz.wtf> Eli the Bearded wrote:

In comp.lang.perl.misc, Andreas Fenner <Andis_Spamtonne@web.de> >>>>>>> wrote:

*SKIP*

? If so, let's continue this on comp.lang.awk.

I'd rather not. This deviated far enough from topic (whatever that was; honestly, with OP it's hard to tell). I hope that I've got safeguards installed to avoid traps like this again. I can't imagine that outside
will be appriciated.

*CUT*

--
Torvalds' goal for Linux is very simple: World Domination
Stallman's goal for GNU is even simpler: Freedom

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

Eric Pozharski <whynot@pozharski.name> writes:

with <87k0j2kj70.fsf@nosuchdomain.example.com> Keith Thompson wrote:

Eric Pozharski <whynot@pozharski.name> writes:

with <87ee9claxk.fsf@nosuchdomain.example.com> Keith Thompson wrote:

Eric Pozharski <whynot@pozharski.name> writes:

with <87mto1lr4r.fsf@nosuchdomain.example.com> Keith Thompson wrote: >>>>>> Eric Pozharski <whynot@pozharski.name> writes:

with <eli$2109231453@qaz.wtf> Eli the Bearded wrote:

In comp.lang.perl.misc, Andreas Fenner <Andis_Spamtonne@web.de> >>>>>>>> wrote:

*SKIP*

? If so, let's continue this on comp.lang.awk.

I'd rather not. This deviated far enough from topic (whatever that was; honestly, with OP it's hard to tell). I hope that I've got safeguards installed to avoid traps like this again. I can't imagine that outside
will be appriciated.

*CUT*

OK, one last response and then I'll bail out of this discussion.

Upthread, you said that "'awk' of 'busybox' even fails to evaluate NR
(looks like it always 1)".

Since NR is a fundamental feature of awk, going back to the original implementation, my tentative conclusion is that this was most likely
operator error. An implementation of awk not implementing NR correctly
would be astonishing, requiring strong evidence, which I haven't seen.
User error seems much more likely.

Back to Perl.

--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for Philips
void Void(void) { Void(); } /* The recursive call of the void */

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On 27/09/2021 19:53, Keith Thompson wrote:

Eric Pozharski <whynot@pozharski.name> writes:

with <87k0j2kj70.fsf@nosuchdomain.example.com> Keith Thompson wrote:

Eric Pozharski <whynot@pozharski.name> writes:

with <87ee9claxk.fsf@nosuchdomain.example.com> Keith Thompson wrote:

Eric Pozharski <whynot@pozharski.name> writes:

with <87mto1lr4r.fsf@nosuchdomain.example.com> Keith Thompson wrote: >>>>>>> Eric Pozharski <whynot@pozharski.name> writes:

with <eli$2109231453@qaz.wtf> Eli the Bearded wrote:

In comp.lang.perl.misc, Andreas Fenner <Andis_Spamtonne@web.de> >>>>>>>>> wrote:

*SKIP*

? If so, let's continue this on comp.lang.awk.

I'd rather not. This deviated far enough from topic (whatever that was;
honestly, with OP it's hard to tell). I hope that I've got safeguards
installed to avoid traps like this again. I can't imagine that outside
will be appriciated.

*CUT*

OK, one last response and then I'll bail out of this discussion.

Upthread, you said that "'awk' of 'busybox' even fails to evaluate NR
(looks like it always 1)".

Since NR is a fundamental feature of awk, going back to the original implementation, my tentative conclusion is that this was most likely
operator error. An implementation of awk not implementing NR correctly
would be astonishing, requiring strong evidence, which I haven't seen.
User error seems much more likely.

Back to Perl.

Is this problem as simple as someone confusing NF with NR?

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

with <sitljv$ot4$1@dont-email.me> Certes wrote:

On 27/09/2021 19:53, Keith Thompson wrote:

Eric Pozharski <whynot@pozharski.name> writes:

with <87k0j2kj70.fsf@nosuchdomain.example.com> Keith Thompson wrote:

Eric Pozharski <whynot@pozharski.name> writes:

with <87ee9claxk.fsf@nosuchdomain.example.com> Keith Thompson wrote: >>>>>> Eric Pozharski <whynot@pozharski.name> writes:

with <87mto1lr4r.fsf@nosuchdomain.example.com> Keith Thompson wrote: >>>>>>>> Eric Pozharski <whynot@pozharski.name> writes:

with <eli$2109231453@qaz.wtf> Eli the Bearded wrote:

In comp.lang.perl.misc, Andreas Fenner <Andis_Spamtonne@web.de> >>>>>>>>>> wrote:

*SKIP*

? If so, let's continue this on comp.lang.awk.

I'd rather not. This deviated far enough from topic (whatever that
was; honestly, with OP it's hard to tell). I hope that I've got
safeguards installed to avoid traps like this again. I can't
imagine that outside will be appriciated.

*SKIP*

Back to Perl.

Is this problem as simple as someone confusing NF with NR?

Kind sir, rest assured that your magical seeing is enormous -- indeed,
it is. I've just checked, 1.31.1 (of android) is fine; 1.20 (of linux)
is fine too. Also learned valuable lesson (not only records must be multi-field, also tests must be multi-record).

p.s. See what happens when threre are no safeguards?

--
Torvalds' goal for Linux is very simple: World Domination
Stallman's goal for GNU is even simpler: Freedom

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

Hongyi Zhao <hongyi.zhao@gmail.com> writes:

What's the perl command corresponding to the following awk code:

$ awk '{sub(/[0-9]+$/, $NF+1); print}' file

perl -ape 's/[0-9]+$/$F[-1]+1/e'

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

Rainer Weikusat <rweikusat@talktalk.net> writes:

Hongyi Zhao <hongyi.zhao@gmail.com> writes:

What's the perl command corresponding to the following awk code:

$ awk '{sub(/[0-9]+$/, $NF+1); print}' file

perl -ape 's/[0-9]+$/$F[-1]+1/e'

Perl version :-):

perl -ape 's/\d+$/$F[-1]+1/e'

Without using autosplit:

perl -pe 's/(-\K)?(\d+)$/"$1$2"+1/e'

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

Rainer Weikusat <rweikusat@talktalk.net> writes:

Rainer Weikusat <rweikusat@talktalk.net> writes:

Hongyi Zhao <hongyi.zhao@gmail.com> writes:

What's the perl command corresponding to the following awk code:

$ awk '{sub(/[0-9]+$/, $NF+1); print}' file

[...]

Without using autosplit:

perl -pe 's/(-\K)?(\d+)$/"$1$2"+1/e'

Doesn't work for non-numerical strings ending with a sequence of
numbers.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

Hongyi Zhao <hongyi.zhao@gmail.com> writes:

What's the perl command corresponding to the following awk code:

$ awk '{sub(/[0-9]+$/, $NF+1); print}' file

Regards,
HZ

It's actually possible to do this without autosplit:

[rw@doppelsaurus]/tmp#cat f
0
a1
aa 2
aaa 3 4
bbb
ccc -2
dddd abc4
[rw@doppelsaurus]/tmp#awk '{sub(/[0-9]+$/, $NF+1); print}' f
1
a1
aa 3
aaa 3 5
bbb
ccc --1
dddd abc1
[rw@doppelsaurus]/tmp#perl -pe 's/(\S*\K)(\d+)$/1+"$1$2"/e' f
1
a1
aa 3
aaa 3 5
bbb
ccc --1
dddd abc1

:-)

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

Rainer Weikusat <rweikusat@talktalk.net> wrote:

Hongyi Zhao <hongyi.zhao@gmail.com> writes:

What's the perl command corresponding to the following awk code:

$ awk '{sub(/[0-9]+$/, $NF+1); print}' file

It's actually possible to do this without autosplit:

[rw@doppelsaurus]/tmp#cat f
0
a1
aa 2
aaa 3 4
bbb
ccc -2
dddd abc4
[rw@doppelsaurus]/tmp#awk '{sub(/[0-9]+$/, $NF+1); print}' f
1
a1
aa 3
aaa 3 5
bbb
ccc --1
dddd abc1
[rw@doppelsaurus]/tmp#perl -pe 's/(\S*\K)(\d+)$/1+"$1$2"/e' f
1
a1
aa 3
aaa 3 5
bbb
ccc --1
dddd abc1

The awk is of course slightly pathological (substituting the trailing
numeric string for whatever $NF+1 happens to evaluate to, which quite
often is 0+1), so this does work a bit nicer with the more unusual
cases, also understands signs:

% perl -pe 's/[+-]?\d+$/1+$&/e;' f
1
a2
aa 3
aaa 3 5
bbb
ccc -1
dddd abc5

--
/* * * Otto J. Makela <om@iki.fi> * * * * * * * * * */
/* Phone: +358 40 765 5772, ICBM: N 60 10' E 24 55' */
/* Mail: Mechelininkatu 26 B 27, FI-00100 Helsinki */
/* * * Computers Rule 01001111 01001011 * * * * * * */

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

om@iki.fi (Otto J. Makela) writes:

Rainer Weikusat <rweikusat@talktalk.net> wrote:

Hongyi Zhao <hongyi.zhao@gmail.com> writes:

What's the perl command corresponding to the following awk code:

$ awk '{sub(/[0-9]+$/, $NF+1); print}' file

It's actually possible to do this without autosplit:

[...]

[rw@doppelsaurus]/tmp#perl -pe 's/(\S*\K)(\d+)$/1+"$1$2"/e' f
1
a1
aa 3
aaa 3 5
bbb
ccc --1
dddd abc1

The awk is of course slightly pathological (substituting the trailing
numeric string for whatever $NF+1 happens to evaluate to, which quite
often is 0+1), so this does work a bit nicer with the more unusual
cases, also understands signs:

% perl -pe 's/[+-]?\d+$/1+$&/e;' f

This doesn't work at all because it's not equivalent to the original awk script. It should have --1 in the second-to-last-line and abc1 in the
last.

1
a2
aa 3
aaa 3 5
bbb
ccc -1
dddd abc5

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

Rainer Weikusat <rweikusat@talktalk.net> wrote:

om@iki.fi (Otto J. Makela) writes:

The awk is of course slightly pathological (substituting the trailing
numeric string for whatever $NF+1 happens to evaluate to, which quite
often is 0+1), so this does work a bit nicer with the more unusual
cases, also understands signs:

% perl -pe 's/[+-]?\d+$/1+$&/e;' f

This doesn't work at all because it's not equivalent to the original
awk script. It should have --1 in the second-to-last-line and abc1 in
the last.

When I said the awk script is slightly pathological, I meant it due to
the inconsistent internal logic most likely doesn't really produce the
results the original coder was expecting, and thus I presented something
that is simple and perhaps a bit more logical in what it outputs.

I am sorry to have caused such confusion.
--
/* * * Otto J. Makela <om@iki.fi> * * * * * * * * * */
/* Phone: +358 40 765 5772, ICBM: N 60 10' E 24 55' */
/* Mail: Mechelininkatu 26 B 27, FI-00100 Helsinki */
/* * * Computers Rule 01001111 01001011 * * * * * * */

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

om@iki.fi (Otto J. Makela) writes:

Rainer Weikusat <rweikusat@talktalk.net> wrote:

om@iki.fi (Otto J. Makela) writes:

The awk is of course slightly pathological (substituting the trailing
numeric string for whatever $NF+1 happens to evaluate to, which quite
often is 0+1), so this does work a bit nicer with the more unusual
cases, also understands signs:

% perl -pe 's/[+-]?\d+$/1+$&/e;' f

This doesn't work at all because it's not equivalent to the original
awk script. It should have --1 in the second-to-last-line and abc1 in
the last.

When I said the awk script is slightly pathological, I meant it due to
the inconsistent internal logic most likely doesn't really produce the results the original coder was expecting,

I don't think the original coder was expecting anything except trying to
do a "my awk is longer than your perl"-demonstration.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)