Search multiple lines in a file

cbtshare · 12-06-2019, 11:17 PM

Hello All,

I have a file with a particular pattern that I want.(with the title ParameterValue)

Code:

"ParameterName": 
                "ParameterValue": 
                "Description": 
                "Source": "
                "ApplyType": 
                "DataType": 
                "AllowedValues": 
                "IsModifiable":

The file also has patterns with no ParameterValue i.e

Code:

"ParameterName": 
                "Description": 
                "Source": "
                "ApplyType": 
                "DataType": 
                "AllowedValues": 
                "IsModifiable":

Is there a way I can get only content that corresponding ParameterName AND ParameterValue

The values are in a file calle dbparam2

I have tried the following:

Only gets ParameterValue, but I need the name

Code:

grep -- 'ParameterValue*' dbparam2

gets both, but it get ParameterName ONLY values as well, they dont match

Code:

grep -e ParameterName -e ParameterValue dbparam2

Shows nothing

Code:

awk '/ParameterName/ && /ParameterValue/' dbparam2

Please assist me, thank you

syg00 · 12-07-2019, 12:02 AM

*nix is stream orientated - a record ends at the newline. So by definition you can't test for multiple values across newlines - but we've all tried. Well, you can even with grep, but the regex can get monstrous. There is (or was) a multiline grep available - same comment re the regex.
If the ParameterValue is always immediately after ParameterName, search for the former and specify you want 1 line of context before the match. See the manpage. Easy.
If not, you'll need to flag when you hit ParameterName and keep looking - awk is the better tool then.

grail · 12-07-2019, 12:04 AM

Please show a full example, ie including the 'name'. Also, include the desired output

As for the information, will ParameterValue always follow ParameterName or can it be anywhere in the list of values?

cbtshare · 12-07-2019, 12:11 AM

Quote:

Originally Posted by grail

Please show a full example, ie including the 'name'. Also, include the desired output

As for the information, will ParameterValue always follow ParameterName or can it be anywhere in the list of values?

Yes, ParameterName always precedes ParameterValue , but there are also line without ParameterValue and those lines are what I do not want.
An example is

Code:

               "ParameterName": "tmpdir",
                "ParameterValue": "/rdsdbdata/tmp/",
                "Description": "The directory used for temporary files and temporary tables",
                "Source": "system",
                "ApplyType": "static",
                "DataType": "string",
                "IsModifiable": false

a desired output would be just to show

Code:

"ParameterName": "tmpdir",
 "ParameterValue": "/rdsdbdata/tmp/",

or even the whole lines

Code:

               "ParameterName": "tmpdir",
                "ParameterValue": "/rdsdbdata/tmp/",
                "Description": "The directory used for temporary files and temporary tables",
                "Source": "system",
                "ApplyType": "static",
                "DataType": "string",
                "IsModifiable": false

berndbausch · 12-07-2019, 12:36 AM

Quote:

Originally Posted by cbtshare

Shows nothing

Code:

awk '/ParameterName/ && /ParameterValue/' dbparam2

Because this awk program finds lines that contain both.

You could create an awk program that remembers ParameterName and only outputs it when it encounters ParameterValue, something like (not tested):

Code:

/ParameterName/   { PN = $0 }
/ParameterValue/ { print PN; print }

grail · 12-07-2019, 12:47 AM

SO maybe something like:

Code:

awk '/ParameterName/{out = $0; getline; if(/ParameterValue/)print out RS $0}' file_name

cbtshare · 12-07-2019, 01:04 AM

Quote:

Originally Posted by grail

SO maybe something like:

Code:

awk '/ParameterName/{out = $0; getline; if(/ParameterValue/)print out RS $0}' file_name

amazing, thank you !

syg00 · 12-07-2019, 04:41 AM

What's wrong with KISS ?.

Code:

grep -B1 ParameterValue input.file

MadeInGermany · 12-07-2019, 04:49 AM

In sed the N command appends the next line.

Code:

sed '/"ParameterName":/!d;N;/"ParameterValue":/!d' file_name

Delete if not "ParameterName": otherwise N, delete if not "ParameterValue": otherwise default-print.
Or

Code:

sed -n '/"ParameterName":/{N;/"ParameterValue":/p;}' file_name

No default-print. If "ParameterName": then N, if "ParameterValue": then print.