CODEWITHSUNDEEP
regexawk
Chris
Chris

Reputation: 1019

awk processing with a variable

input file is:

line1 [time-1] abcdef
line2 [time-1] absde1
line3 [time-1] abcdef
line4 [time-1] zzzzzz

this command is working fine:

$ str="abcdef|zzzzzz"
$ awk '!($0~/('"$str"')$/)' test_input
line2 [time-1] absde1

following command fails:

$ str="[time-1] abcdef|[time-1] zzzzzz"
$ echo "${str}"
[time-1] abcdef|[time-1] zzzzzz
$ awk '!($0~/('"$str"')$/)' test_input
awk: fatal: Invalid range end: /([time-1] abcdef|[time-1] zzzzzz)$/
$

Is it possible to pass variable with such string to awk too?

Upvotes: 2

Views: 141

Answers (2)

Gilberto Treviño
Gilberto Treviño

Reputation: 136

You just have to escape the square brackets

$ str="\[time-1\] abcdef|\[time-1\] zzzzzz"
$ awk '!($0~/('"$str"')$/)' test_input
line2 [time-1] absde1

--- Edit --------------------------

To create the str variable with escaped characters

str="[time-1] abcdef|[time-1] zzzzzz" | sed -e 's/[]\/$*.^[]/\\&/g'

This way, the pipe-separated list can be an automatically generated list.

Upvotes: 0

anubhava
anubhava

Reputation: 785128

One more awk:

awk -v str="$str" 'BEGIN {
   n = split(str, a, "|")
}
{
   for (i=1; i<=n; i++)
      if (index($0, a[i]))
         next
   print
}' file


line2 [time-1] absde1

Reason why you cannot just use $str as regex is that you have regex meta characters such as [, ] etc.

Upvotes: 1

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