BSD awk bug ?

[Tomoya Tabuchi]

On Wed, Aug 16, 2017 at 10:14:46AM +0900, KIRIYAMA Kazuhiko wrote:
> admin at tbedfpc:~/tmp % ll
> total 12
> -rw-r--r--  1 admin  admin  235 Aug 16 10:01 regex-1.sh
> -rw-r--r--  1 admin  admin  236 Aug 16 10:01 regex-2.sh
> -rw-r--r--  1 admin  admin  260 Aug 16 10:01 regex.sh
> admin at tbedfpc:~/tmp % cat regex.sh 
> #!/bin/sh
> 
> data='1 2 3 4 5 6
> 1 2 3 4 5
> 1 2 3 4 5 6
> 1 2 3 4 5 6
> 1 2 3 4
> 1 2 3'
> 
> IFS=$'\n'
> for datum in $data; do
>     if echo "$datum" | egrep -q  '^([^[:space:]]+[[:space:]]+){5}'; then
>         echo "$datum"
>     else
>         echo "Not 6 components! : \"$datum\""
>     fi
> done
> admin at tbedfpc:~/tmp % sh ./regex.sh 
> 1 2 3 4 5 6
> Not 6 components! : "1 2 3 4 5"
> 1 2 3 4 5 6
> 1 2 3 4 5 6
> Not 6 components! : "1 2 3 4"
> Not 6 components! : "1 2 3"
> admin at tbedfpc:~/tmp % cat regex-1.sh 
> #!/bin/sh
> 
> _f_awk='
> {
>         if ($0 ~ /^([^[:space:]]+[[:space:]]+){5}/) {
>                 print $0
>         } else {
>                 print "Not 6 components! : \"" $0 "\""
>         }
> }'
> 
> data='1 2 3 4 5 6
> 1 2 3 4 5
> 1 2 3 4 5 6
> 1 2 3 4 5 6
> 1 2 3 4
> 1 2 3'
> 
> echo "$data" | awk "$_f_awk"
> admin at tbedfpc:~/tmp % sh ./regex-1.sh 
> Not 6 components! : "1 2 3 4 5 6"
> Not 6 components! : "1 2 3 4 5"
> Not 6 components! : "1 2 3 4 5 6"
> Not 6 components! : "1 2 3 4 5 6"
> Not 6 components! : "1 2 3 4"
> Not 6 components! : "1 2 3"
> admin at tbedfpc:~/tmp % cat regex-2.sh
> #!/bin/sh
> 
> _f_awk='
> {
>         if ($0 ~ /^([^[:space:]]+[[:space:]]+){5}/) {
>                 print $0
>         } else {
>                 print "Not 6 components! : \"" $0 "\""
>         }
> }'
> 
> data='1 2 3 4 5 6
> 1 2 3 4 5
> 1 2 3 4 5 6
> 1 2 3 4 5 6
> 1 2 3 4
> 1 2 3'
> 
> echo "$data" | gawk "$_f_awk"
> admin at tbedfpc:~/tmp % sh ./regex-2.sh
> 1 2 3 4 5 6
> Not 6 components! : "1 2 3 4 5"
> 1 2 3 4 5 6
> 1 2 3 4 5 6
> Not 6 components! : "1 2 3 4"
> Not 6 components! : "1 2 3"
> admin at tbedfpc:~/tmp % uname -a
> FreeBSD tbedfpc 12.0-CURRENT FreeBSD 12.0-CURRENT #0 r321597: Thu Jul 27 12:30:57 UTC 2017     root at tbedfc:/usr/obj/usr/src/sys/GENERIC  amd64
> admin at tbedfpc:~/tmp % pkg info -aI|grep gawk
> gawk-4.1.4_1                   GNU version of Awk
> admin at tbedfpc:~/tmp % 
> 
> 
> Is this the BSD awk (/usr/bin/awk) bug ?
> 
> ---
> KIRIYAMA Kazuhiko
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Hello Kiriyama-san,

The man page awk(1) says that {m,n} matcning is not supported. The "{5}"
part matches the literal sequence of characters it's made out of, I suppose.

Someone please correct me if I'm wrong.

Regards,
Tomoya