Awk not working in bash script when use variable in comparison

Question

Following is my bash script. If I use varible oid to compare in awk, it doesnt show matching line.

oid="3586302804992"
SYMBOL_CSV_FILE="symbol/BAC"
awk -F, '$5 == $oid' "$SYMBOL_CSV_FILE"
echo "2nd"
awk -F, '$5 == "3586302804992"' "$SYMBOL_CSV_FILE"

O/P is

2nd
BAC,1,O,1,3586302804992

symbol/BAK file contents are

BAC,1,O,1,3586302804992o

Putting "" around $oid , on 3rd line, doesnt make any difference.

To use bash variables inside an awk script, you need to "pass" them with -v. For example num=3; awk -v n=$num 'BEGIN{print n}'. — fedorqui
– fedorqui, Commented Aug 13, 2013 at 11:50

anubhava · Accepted Answer · 2013-08-13 11:51:10Z

6

Instead of:

awk -F, '$5 == $oid' "$SYMBOL_CSV_FILE"

use it like this:

awk -F "," -v oid="$oid" '$5 == oid' "$SYMBOL_CSV_FILE"

answered Aug 13, 2013 at 11:51

anubhava

790k67 gold badges603 silver badges671 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

rahul.deshmukhpatil Over a year ago

thanks, Worked in right way. @Anubhava: the variable passing mechanism to awk has any specific reason?

anubhava Over a year ago

Yes -v is standard way to pass variables from shell to awk. These variable then become standard awk variables and you can use them without quoting or $ inside awk scripts.

Didier Trosset · Accepted Answer · 2013-08-13 13:49:23Z

1

For bash to interpret your variables, you have to use the double quotes. Single quotes will send $oid as is to your program.

Then, as the $5 will also be interpreted, and you don't want to! You have to escape the $.

In the end, you have:

awk -F, "\$5 == $oid" "$SYMBOL_CSV_FILE"
        ^^          ^

edited Aug 13, 2013 at 13:49

answered Aug 13, 2013 at 11:50

Didier Trosset

37.6k14 gold badges89 silver badges126 bronze badges

2 Comments

rahul.deshmukhpatil Over a year ago

Giving error as awk: == 3586302804992 awk: ^ syntax error 2nd BAC,1,O,1,3586302804992

Didier Trosset Over a year ago

@rahul.deshmukhpatil Fixed with escaping the $5. Thanks for pointing this out.

Collectives™ on Stack Overflow

Awk not working in bash script when use variable in comparison

2 Answers 2

2 Comments

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related