AWK - question in dealing with variable no of fields

Author

question in dealing with variable no of fields

dada

2004-03-19, 8:23 pm

hi,

i wud like to check if all the records have same number of fields .

i.e

for eg if the file has,
1 2 3
4 5 6
7 8 9
i will print ok
if it is like

1 2
3 4 5
4 5 6
i willl rpint error and exit

also when i tried a simple program i got the following error wat does it mean

gawk: temp:4: (FILENAME=eg.txt FNR=1) fatal: division by zero attempted

the version gawk 3.1.0

Ulrich M. Schwarz

2004-03-19, 8:23 pm

usenetdada@yahoo.com (dada) writes:

> hi,
>
> i wud like to check if all the records have same number of fields .

The following worked, at least on the test data you gave:

NR == 1 { fields_per_record = NF; worked=2;}
NF != fields_per_record { worked=0;
print "Error: line", NR,
"had",NF,"fields",
"where I expected", fields_per_record ".",
"The offending line was:\n",$0;
# exit -1;
}
END { if (worked)
print "ok";
else exit -1;
}

If you comment in the first "exit" line, we will fail as soon as the
first error comes up, but the rest of the input data will remain in
the stream.

With greetings from .de,
Ulrich
--[color=darkred]
Salesman: The glass is future-proof and can handle a 100% capacity upgrade.
Tech support: You need a water upgrade. -- JM, in the sdm

Kenny McCormack

2004-03-19, 8:23 pm

In article <f7851403.0402290314.1632b582@posting.google.com>,
dada <usenetdada@yahoo.com> wrote:
....
>also when i tried a simple program i got the following error wat does it mean

Any particular program, or is it all programs?

>gawk: temp:4: (FILENAME=eg.txt FNR=1) fatal: division by zero attempted

It probably means that division by zero was attempted, at line 1 of data
file "eg.txt", and that gawk flagged this as a fatal error. This probably
occurred at line 4 of script file "temp".

Of course, that's just a layman's interpretation...

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