Find empty value for any name in file

Question

I have a file in the below format:

Name=Dan
Age=45
Name=Alex
Age=35
Cellphone=12345678901
Name=John
Age=
Cellphone=12345678901

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?

Answer 1

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.

Answer 2

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

Answer 3

Using grep with extended regexp:

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

Should print empty keys and corresponding line numbers.