LinuxQuestions.org - [SOLVED] Retrieve default value with grep -e?

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Retrieve default value with grep -e?

I am parsing text files looking for specific entries like so

Code:

    grep -e 'Model' -e 'Manufacturer' -e 'Man Date' -e 'SW Version' -e' SW Name' -e 'HW Version' -e 'Receiver ID' JGMDTV356.HDD

This gives me an output like so

Code:

    Model        = HR24

    Manufacturer  = 100

    Man Date      = 04/14/2010

    SW Version    = 4D1

    HW Version    = 2.3

    Receiver ID  = 035635905389

    Model        = WDCWD5000AVVS-63M8B0 (Dragonfly-0)

The problem is that some files do not have the same number of fields. How can I do something like this?

Code:

  Model        = HR24

    Manufacturer  = 100

    Man Date      = N/A

    SW Version    = 4D1

    HW Version    = N/A

    Receiver ID  = N/A

    Model        = N/A

Could this be done?

Not (easily) with grep - anything with associative arrays (bash, awk, perl, ...) you should be able to do something. Maybe populate all as "n/a" and only print the input if found, else the default. If you don't want to hard-code the fields, make up a file containing them, and read it in.

An ugly hack using a bash script assuming that Model is always present and comes first and the other fields come in the same order if present.

Code:

#! /bin/bash



while read line

do

  if [[ $line =~ Model.* ]]; then

    echo $line

    read line 

    for i in "Manufacturer" "Man Date" "SW Version" "HW Version" "Receiver ID"

    do

      if [[ $line =~ $i.* ]]; then

        echo $line

        if [ "$i" != "Receiver ID" ]; then

          read line

        fi

      else

        echo $i" = N/A"

      fi

    done

  fi

done < test.txt

If test.txt contains:

Code:

    Model        = HR24

    Manufacturer  = 100

    Man Date      = 04/14/2010

    SW Version    = 4D1

    HW Version    = 2.3

    Receiver ID  = 035635905389

    Model        = WDCWD5000AVVS-63M8B0 (Dragonfly-0)

    Manufacturer  = 100

    SW Version    = 4D1

then the ouput is:

Quote:

Model = HR24
Manufacturer = 100
Man Date = 04/14/2010
SW Version = 4D1
HW Version = 2.3
Receiver ID = 035635905389
Model = WDCWD5000AVVS-63M8B0 (Dragonfly-0)
Manufacturer = 100
Man Date = N/A
SW Version = 4D1
HW Version = N/A
Receiver ID = N/A

Quote:

Originally Posted by allend (Post 4513805)

An ugly hack using a bash script assuming that Model is always present and comes first and the other fields come in the same order if present.

Code:

#! /bin/bash



while read line

do

  if [[ $line =~ Model.* ]]; then

    echo $line

    read line 

    for i in "Manufacturer" "Man Date" "SW Version" "HW Version" "Receiver ID"

    do

      if [[ $line =~ $i.* ]]; then

        echo $line

        if [ "$i" != "Receiver ID" ]; then

          read line

        fi

      else

        echo $i" = N/A"

      fi

    done

  fi

done < test.txt

If test.txt contains:

Code:

    Model        = HR24

    Manufacturer  = 100

    Man Date      = 04/14/2010

    SW Version    = 4D1

    HW Version    = 2.3

    Receiver ID  = 035635905389

    Model        = WDCWD5000AVVS-63M8B0 (Dragonfly-0)

    Manufacturer  = 100

    SW Version    = 4D1

then the ouput is:

Ugly maybe, but this is a clever hack.

Unfortunately, this won't fly. Depending on the supplier that sends the file, Model may not even be present.

I need to devise a strategy where the relevant stuff is captured and the rest is rejected.

Thanks for your time.

In that case, I concur with syg00, grep is not the tool here, you need a proper prog lang (in my case Perl) that can handle arbitrary data layouts that may have missing elements.