I have a file in the below format:


This file has got 1000's of data items in above format, Name=Value.

If values are missing, and I want to find these in below output as missing value for Age.

I tried by using the cut command, cut -d “=“ -f2 > some file, then grep for an empty line, grep -n ‘[[:blank:]]’ file, then display the line number in the original file.

But since I have multiple files, this method looks complicated.

Is there any simpler method for this?

  • I did not understand what's the output you want for a single file. Could insert an example? – aborruso Jan 5 '19 at 18:00

You could try using this:

cat <filename> | sed "s/ /\n/g" | grep "=$"

This will replace your spaces to new lines (which will not work if you have values contaning spaces) and then look for entries with = followed by line end.

  • 1
    Since there are multiple files and the field name is always the same, it might be useful to use cat -n, which will display the line number. – ChatterOne Jan 2 '19 at 9:32
  • This will also report values that end in =, e.g. key=value=. – Kusalananda Jan 2 '19 at 11:44

If you treat your file as delimited, then you can match and output any lines whose second field consists of at most whitespace:

awk -F= '$2 ~ /^[ \t]*$/' file

Using grep with extended regexp:

grep -Eno "[A-Za-z]+=( |$)" /path/to/file

Should print empty keys and corresponding line numbers.

  • Thanks , this is also helpful , above solution worked , thanks – SuS Jan 2 '19 at 8:00
  • This too would disallow values to end in =. – Kusalananda Jan 2 '19 at 11:45

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