awk count characters of a row
 

Hi!

I have a huge data set which does not have the same amount of columns in each row. However, the columns are aligned. I would like to check the columns that start at the 20th character of the line and see if the value at that column is larger then 50. In that case I want to print that whole line. Is there an easy way to do this with AWK? Your help is very much appreciated!

cheers,
Tomas

First, we'll need to know how the data is formatted--e.g. how is a column defined? (It could have the data separated by commas, or it could be based on the number of characters. Can you simply post a sample of the data?

Second, why are you restricting the solution to AWK?

Case A. The data is a number
strng=substr($0,20,length($0)-19)
n=split(strng,arra," ")
if arra[1] > 50 {
... error routines
}

Case B. The data is a string.
strng=substr($0,20,length($0)-19)
n=split(strng,arra," ")
if length(arra[1]) > 50 {
... error routines
}

OK

Assumption (in a SDF - fixed length ASCII - file , the field separator is usually blank. ie. padded to align.

OK

Thanks for the reply!

The data file is agn.dat at http://cdsarc.u-strasbg.fr/viz-bin/C...8&target=http&

And this is the code that I used:

#!/bin/awk -f

strng=substr($0,83,length($0)-82)
n=split(strng,arra," ")
if arra[1]<17
{
print $0
}

However, it gives the following error:

awk: /home/tomas/scripts/agn:5: if arra[1]<17
awk: /home/tomas/scripts/agn:5: ^ syntax error

Any idea what I do wrong?

As you want to execute all commands for each line, they need to be enclosed in curly braces around all statements. It’s one case in you awk script.

NB: without giving the length substr will return the rest of the line.

@ Reuti: So you mean like this?:

#!/bin/awk -f

{
strng=substr($0,83,length($0)-82)
n=split(strng,arra," ")
if arra[1] < 17 {
print $0
}
}

It still gives the following error:

awk: /home/tomas/scripts/agn:6: if arra[1] < 17 {
awk: /home/tomas/scripts/agn:6: ^ syntax error
awk: /home/tomas/scripts/agn:6: if arra[1] < 17 {
awk: /home/tomas/scripts/agn:6: ^ syntax error

Oh, I edited too much at once: and parenthesis around the comparison.

Thanks! It works great now.

So this script will check if the number starting at the 83th character of a line is smaller than 11, and if so it will print that whole line:

#!/bin/awk -f
{
strng=substr($0,83,length($0)-82)
n=split(strng,arra," ")
if ( arra[1] < 11 )
{
print $0
}
}