Ubuntu – Find and report line numbers of empty lines in text file

command linetext processing

I have text file containing 14000+ lines. it contains some data I am using for data training of speech recognition.

I created that file via coding of java and due to some semantic error a few of the lines are empty. Every time I run training it gives an error after about 30 minutes complaining that there is a empty line.

Is there any code/script/command which can give me list of line numbers with empty lines, so I can fill those empty lines and save my time?

Working should be like:

I will input a file.txt and it will give me

line number 1121,1212,1450,13000 and so on ... are empty in file.txt

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Best Answer

You can find the empty lines, and their line numbers, with 

grep -E --line-number --with-filename '^$' file.txt

An example: 

w3@aardvark:~(0)$ grep -E --line-number --with-filename '^$' file.txt
file.txt:1:
file.txt:3:
file.txt:4:
w3@aardvark:~(0)$ cat -n file.txt
     1  
     2  Not empty
     3  
     4  
     5  Not empty
w3@aardvark:~(0)$

If your "empty" lines contain blanks or TABs, use: 

grep -E --line-number --with-filename '^\s*$' file.txt
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