Re: [PLUG] awk: is field blank?
Awk variable NF contains number of fieds. So:
awk 'NF==8 { print }'
Will print lines with 8 fields.
Best, Tomas
On Sat, Oct 30, 2021, 11:31 Rich Shepard wrote:
> I've a 351K line file with 8 fields. About 50K of those lines has $8 blank.
> I want awk to print only rows with values in all 8 fields. I'm not finding
> how to tell awk to print $0 if $8 is not blank.
>
> My awk/sed book doesn't seem to have this information and my web searches
> aren't finding the answer, either.
>
> Clue needed.
>
> Rich
>
Re: [PLUG] awk: is field blank?
On Sat, 30 Oct 2021, Robert Citek wrote:
Simplified version of your script:
BEGIN {FS="|"}
$8 != " "
Robert,
Thanks for the insights. I've not been aware of some before.
Regards,
Rich
Re: [PLUG] awk: is field blank?
A few pointers:
- {print $0} and {print} are the same
- {print} is the default action for any pattern match
- since you are printing the entire line, the OFS isn't used and,
therefore, doesn't need to be specified
- you don't need to specify an "if" as that is part of the structure of an
awk script: conditional {action}
Simplified version of your script:
BEGIN {FS="|"}
$8 != " "
... and an example:
$ echo -e "a|b|c|d\na|b||d" | awk -F'|' '$3 != ""'
a|b|c|d
Regards,
- Robert
On Sat, Oct 30, 2021 at 9:51 AM Rich Shepard
wrote:
> On Sat, 30 Oct 2021, Robert Citek wrote:
>
> > Here's a sample:
> > $ echo -e "a\tb\tc\td\na\tb\t\td" | awk -F'\t' '{print}'
> > a b c d
> > a b d
>
> > $ echo -e "a\tb\tc\td\na\tb\t\td" | awk -F'\t' '$3=="" {print}'
> > a b d
>
> My script uses if and awk doesn't like how I've used it:
> BEGIN {FS="|";OFS="|"}
> if {$8!=""} {
>print $0
> }
>
> gawk -f clean-broadway-file.awk mean-vel-broadway.dat > out.dat
> gawk: clean-broadway-file.awk:8: if {$8==""} {
> gawk: clean-broadway-file.awk:8: ^ syntax error
>
> I want to print the whole line only if $8 is not empty.
>
> Thanks,
>
> Rich
>
Re: [PLUG] awk: is field blank?
On Sat, 30 Oct 2021, Robert Citek wrote:
Here's a sample:
$ echo -e "a\tb\tc\td\na\tb\t\td" | awk -F'\t' '{print}'
a b c d
a b d
$ echo -e "a\tb\tc\td\na\tb\t\td" | awk -F'\t' '$3=="" {print}'
a b d
My script uses if and awk doesn't like how I've used it:
BEGIN {FS="|";OFS="|"}
if {$8!=""} {
print $0
}
gawk -f clean-broadway-file.awk mean-vel-broadway.dat > out.dat
gawk: clean-broadway-file.awk:8: if {$8==""} {
gawk: clean-broadway-file.awk:8: ^ syntax error
I want to print the whole line only if $8 is not empty.
Thanks,
Rich
Re: [PLUG] awk: is field blank?
... and to negate the conditional use an exclamation point (!) :
$ echo -e "a\tb\tc\td\na\tb\t\td" | awk -F'\t' '$3 != "" {print}'
a b c d
Regards,
- Robert
On Sat, Oct 30, 2021 at 9:46 AM Robert Citek wrote:
> Sorry, this item didn't get pasted in my last post:
>
> $ echo -e "a\tb\tc\td\na\tb\t\td" | awk '{print $1" = "$2" = "$3" = "$4}'
> a = b = c = d
> a = b = d =
>
> Notice that you have to specify the field separator with the -F option,
> otherwise awk compresses consecutive whitespace characters by default.
>
> Regards,
> - Robert
>
> On Sat, Oct 30, 2021 at 9:41 AM Robert Citek
> wrote:
>
>> Hello Rich,
>>
>> Here's a sample:
>>
>> $ echo -e "a\tb\tc\td\na\tb\t\td" | awk -F'\t' '{print}'
>> a b c d
>> a b d
>>
>> $ echo -e "a\tb\tc\td\na\tb\t\td" | awk -F'\t' '$3=="" {print}'
>> a b d
>>
>> Good luck and let us know how it goes.
>>
>> Regards,
>> - Robert
>>
>> On Sat, Oct 30, 2021 at 9:31 AM Rich Shepard
>> wrote:
>>
>>> I've a 351K line file with 8 fields. About 50K of those lines has $8
>>> blank.
>>> I want awk to print only rows with values in all 8 fields. I'm not
>>> finding
>>> how to tell awk to print $0 if $8 is not blank.
>>>
>>> My awk/sed book doesn't seem to have this information and my web searches
>>> aren't finding the answer, either.
>>>
>>> Clue needed.
>>>
>>> Rich
>>>
>>
Re: [PLUG] awk: is field blank?
Sorry, this item didn't get pasted in my last post:
$ echo -e "a\tb\tc\td\na\tb\t\td" | awk '{print $1" = "$2" = "$3" = "$4}'
a = b = c = d
a = b = d =
Notice that you have to specify the field separator with the -F option,
otherwise awk compresses consecutive whitespace characters by default.
Regards,
- Robert
On Sat, Oct 30, 2021 at 9:41 AM Robert Citek wrote:
> Hello Rich,
>
> Here's a sample:
>
> $ echo -e "a\tb\tc\td\na\tb\t\td" | awk -F'\t' '{print}'
> a b c d
> a b d
>
> $ echo -e "a\tb\tc\td\na\tb\t\td" | awk -F'\t' '$3=="" {print}'
> a b d
>
> Good luck and let us know how it goes.
>
> Regards,
> - Robert
>
> On Sat, Oct 30, 2021 at 9:31 AM Rich Shepard
> wrote:
>
>> I've a 351K line file with 8 fields. About 50K of those lines has $8
>> blank.
>> I want awk to print only rows with values in all 8 fields. I'm not finding
>> how to tell awk to print $0 if $8 is not blank.
>>
>> My awk/sed book doesn't seem to have this information and my web searches
>> aren't finding the answer, either.
>>
>> Clue needed.
>>
>> Rich
>>
>
Re: [PLUG] awk: is field blank?
Hello Rich,
Here's a sample:
$ echo -e "a\tb\tc\td\na\tb\t\td" | awk -F'\t' '{print}'
a b c d
a b d
$ echo -e "a\tb\tc\td\na\tb\t\td" | awk -F'\t' '$3=="" {print}'
a b d
Good luck and let us know how it goes.
Regards,
- Robert
On Sat, Oct 30, 2021 at 9:31 AM Rich Shepard
wrote:
> I've a 351K line file with 8 fields. About 50K of those lines has $8 blank.
> I want awk to print only rows with values in all 8 fields. I'm not finding
> how to tell awk to print $0 if $8 is not blank.
>
> My awk/sed book doesn't seem to have this information and my web searches
> aren't finding the answer, either.
>
> Clue needed.
>
> Rich
>
[PLUG] awk: is field blank?
I've a 351K line file with 8 fields. About 50K of those lines has $8 blank. I want awk to print only rows with values in all 8 fields. I'm not finding how to tell awk to print $0 if $8 is not blank. My awk/sed book doesn't seem to have this information and my web searches aren't finding the answer, either. Clue needed. Rich
