Gawk length(array) question

Hi All,

The Gawk man page says:
> Starting with version 3.1.5, as a non-standard extension,
> with an array  argument, length() returns the number
> of elements in the array.

It looks like Gawk's length(array) extension does not work inside
functions. Is this a bug or feature or am I missing something? See the
example below. I am using GNU Awk 3.1.6

$ cat testdata
CD NAME
AT Austria
BG Bulgaria
CH Switzerland
DE Germany
EE Estonia
FR France
GR Greece

$ cat test.awk

# Populate array
NR > 1 { array[$1] = $2 }

# Print array length and call function A
END { print "array:",length(array) ; A(array) }

function A(array_A) { print "array_A:", length(array_A) }

$ gawk -f test.awk testdata
array: 7
gawk: test.awk:8: (FILENAME=data FNR=8) fatal: attempt to use array
`array_A (from array)' in a scalar context

BTW, there is no such error if I have asort(array_A) or asorti(array_A)
inside the function.

Hermann

On 3/15/2008 6:08 AM, Hermann Peifer wrote:
> Hi All,
>
> The Gawk man page says: 
>
> It looks like Gawk's length(array) extension does not work inside
> functions. Is this a bug or feature or am I missing something? See the
> example below. I am using GNU Awk 3.1.6
>
> $ cat testdata
> CD NAME
> AT Austria
> BG Bulgaria
> CH Switzerland
> DE Germany
> EE Estonia
> FR France
> GR Greece
>
> $ cat test.awk
>
> # Populate array
> NR > 1 { array[$1] = $2 }
>
> # Print array length and call function A
> END { print "array:",length(array) ; A(array) }
>
> function A(array_A) { print "array_A:", length(array_A) }
>
> $ gawk -f test.awk testdata
> array: 7
> gawk: test.awk:8: (FILENAME=data FNR=8) fatal: attempt to use array
> `array_A (from array)' in a scalar context
>
> BTW, there is no such error if I have asort(array_A) or asorti(array_A)
> inside the function.
>
> Hermann

I get the same result with gawk 3.1.6 for cygwin. Obviously you can work aro
und
it since asort() returns the number of elements in an array just like length
()
is supposed to (or "for (i in array) lgth++" if you don't want to be
gawk-specific) but it does seem like a bug. Anyone know if there's a list of
known gawk bugs on-line somewhere?

Ed.

Ed Morton wrote:
>
> On 3/15/2008 6:08 AM, Hermann Peifer wrote: 
>
> I get the same result with gawk 3.1.6 for cygwin. Obviously you can work a
round
> it since asort() returns the number of elements in an array just like leng
th()
> is supposed to (or "for (i in array) lgth++" if you don't want to be
> gawk-specific) but it does seem like a bug. Anyone know if there's a list 
of
> known gawk bugs on-line somewhere?
>
> 	Ed.
>

Thanks for confirming. I wouldn't know of any online Gawk bug list. If
such a thing existed, it would probably mentioned somewhere at:
http://www.gnu.org/software/gawk/ or http://savannah.gnu.org/projects/gawk

The Gawk man page says:

> BUG REPORTS
> If you find a bug in gawk, please send electronic mail to
bug-gawk@gnu.org.

Hermann

You cannot pass an array as an argument to a function. However, variables in
awk are in general global, so you can use the actual variable name in the
function.

Rajan

"Hermann Peifer" <peifer@gmx.eu> wrote in message
news:47DBAE29.4050709@gmx.eu...
> Hi All,
>
> The Gawk man page says: 
>
> It looks like Gawk's length(array) extension does not work inside
> functions. Is this a bug or feature or am I missing something? See the
> example below. I am using GNU Awk 3.1.6
>
> $ cat testdata
> CD NAME
> AT Austria
> BG Bulgaria
> CH Switzerland
> DE Germany
> EE Estonia
> FR France
> GR Greece
>
> $ cat test.awk
>
> # Populate array
> NR > 1 { array[$1] = $2 }
>
> # Print array length and call function A
> END { print "array:",length(array) ; A(array) }
>
> function A(array_A) { print "array_A:", length(array_A) }
>
> $ gawk -f test.awk testdata
> array: 7
> gawk: test.awk:8: (FILENAME=data FNR=8) fatal: attempt to use array
> `array_A (from array)' in a scalar context
>
> BTW, there is no such error if I have asort(array_A) or asorti(array_A)
> inside the function.
>
> Hermann

On 3/23/2008 6:16 PM, Rajan wrote:

[please don't top-post, fixed below]

>
> "Hermann Peifer" <peifer@gmx.eu> wrote in message
> news:47DBAE29.4050709@gmx.eu...
> 
>
> You cannot pass an array as an argument to a function.

Of course you can.

> However, variables in
> awk are in general global, so you can use the actual variable name in the
> function.

That doesn't help when you're performing the same operation on multiple vari
ables.

Ed.

Apologies, Ed is right.

for (i in array_A) len++ and length(array) works length(array_A) doesn't
work in a function. Thanks!

Rajan

"Ed Morton" <morton@lsupcaemnt.com> wrote in message
news:47E6E6C6.9040502@lsupcaemnt.com...
>
>
> On 3/23/2008 6:16 PM, Rajan wrote:
>
> [please don't top-post, fixed below]
> 
>
> Of course you can.
> 
>
> That doesn't help when you're performing the same operation on multiple
> variables.
>
> Ed.
>

Rajan wrote:
> You cannot pass an array as an argument to a function.

I can. I would even go so far and say: Everybody can.

My bug report has been confirmed by Arnold Robbins and fixed 8 days ago:

Sat Mar 15 22:17:21 2008  Arnold D. Robbins  <arnold@skeeve.com>

* builtin.c (do_length): Handle the case of the parameter being
an array that was a function parameter.


[url]http://cvs.savannah.gnu.org/viewvc/gawk-stable/ChangeLog?root=gawk&view=markup[/ur
l]

Hermann