Awk with a variable

Question

I have an awk command to print out the total number of times "200" occurred in column 26.

awk '$26 ~ /200/{n++}; END {print n+0}' testfile

How do I modify this statement so I can pass 200 as a variable? e.g. if I have a variable $code with a value of 200

Thanks in advance

If code has the value 20 and the number 200 appears in field 26, should that match or not? Are you looking for a match on the WHOLE of field 26 or only part of it? — Ed Morton
– Ed Morton, Commented Feb 5, 2014 at 23:40

Zombo · Accepted Answer · 2014-02-05 19:55:00Z

3

awk '$26 ~ code {n++} END {print n+0}' code=200 testfile

If a filename on the command line has the form var=val it is treated as a variable assignment. The variable var will be assigned the value val.

§ Awk Program Execution

answered Feb 5, 2014 at 19:55

Zombo

1

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2 Comments

n0741337 Over a year ago

That's something I didn't know, but wanted to note after looking it up in The AWK Programming Language: the filename var=val assignment is

performed at the time when that argument would otherwise be accessed as a file.  This type of assignment allows variables to be changed before and after a file is read.

Meaning that order is important.

Ed Morton Over a year ago

@n0741337 Correct and variables assigned that way are not available in the BEGIN section which can cause confusion/mistakes. You should only use this method if you need to change a variables value between files, otherwise awk -v awkvar="$shellvar" is almost always the right approach. See the article I wrote for the comp.unix.shell FAQ at cfajohnson.com/shell/cus-faq-2.html#Q24 for more details.

Kent · Accepted Answer · 2014-02-05 20:13:55Z

2

awk  -v var="$shellVar" '$26~var{n++} END{print n}' file

you see above line how to use shell variable in awk. some notes for your awk one-liner:

print n+0 not necessary. because the n defined by you, not picked from input text, and you explicitly did n++, so it is number type, n+0 makes no sense
the ; before END should be removed
I copied your code about the checking 200 part. but it is risky. if the $26 has only a number, you can consider to use 1*$26 == 200 or $26 == "200" using regex in this situation may give wrong result, think about in your $26, value was : 20200

answered Feb 5, 2014 at 20:13

Kent

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