awk search wildcards

[Bill McNAMARA_1]

hi,
I've got an awk script thanks to help on the itrc that I'm still playing around with.
It's called as follows from within a script.

awk -f script.awk search=$2 filename

The first line of the awk script looks as follows.

$0 ~ "" search{GOTIT=1}

Now, I've discovered that I can have wildcards passed from the shell script command line as follows:

$2 = 20..
will report 2001 2002 2003 -- 2099 etc..
$2 = 20. will report 201 - 209
$2 = 20 will report 1020 1120 etc..

how can I specify that the $2 of 2 only lists 2 and not 2222 2000 200 192 92 etc...



Thanks,
Bill

[Curtis Larson_1 · Accepted solution]

you'll need to do something like this:

$2="^2 | 2$|( 2 )|^2$"

basically, match a 2 with a blank space before and after, at the beginning of a line, at the end of a line, or on a line by itself.

if your pattern, 2 in this case, is delimited by something other then a space or in addition to a space, maybe a tab, you'll need to modify as appropriate.

[James R. Ferguson]

Hi Bill:

Pass a regular expression as:

# awk -f script.awk search=[^$2]$2[^$2] filename

In this case, only isolated character occurances equal to the character defined as $2, following the string "", will be printed from your script.

Regards!

...JRF...

[James R. Ferguson]

Hi (again) Bill:

Ten-points to Curtis! His solution handles the case where the matching single character occurs at the line's end (mine doesn't). Curtis' solution generalizes for the case where you want to match a single character at the beginning of a line too (mine doesn't).

Regards!

...JRF...