How do I find files that do not end with a newline/linefeed?

Question

How can I list normal text (.txt) filenames, that don\'t end with a newline?

e.g.: list (output) this filename:

$ cat a.txt
asdfasdlsad4rand         


        

Answer 1

Use pcregrep, a Perl Compatible Regular Expressions version of grep which supports a multiline mode using -M flag that can be used to match (or not match) if the last line had a newline:

pcregrep -LMr '\n$' .

In the above example we are saying to search recursively (-r) in current directory (.) listing files that don't match (-L) our multiline (-M) regex that looks for a newline at the end of a file ('\n$')

Changing -L to -l would list the files that do have newlines in them.

pcregrep can be installed on MacOS with the homebrew pcre package: brew install pcre

Answer 2

If you are using 'ack' (http://beyondgrep.com) as a alternative to grep, you just run this:

ack -v '\n$'

It actually searches all lines that don't match (-v) a newline at the end of the line.

Answer 3

Ok it's my turn, I give it a try:

find . -type f -print0 | xargs -0 -L1 bash -c 'test "$(tail -c 1 "$0")" && echo "No new line at end of $0"'

Answer 4

Since your question has the perl tag, I'll post an answer which uses it:

find . -type f -name '*.txt' -exec perl check.pl {} +

where check.pl is the following:

#!/bin/perl 

use strict;
use warnings;

foreach (@ARGV) {
    open(FILE, $_);

    seek(FILE, -2, 2);

    my $c;

    read(FILE,$c,1);
    if ( $c ne "\n" ) {
        print "$_\n";
    }
    close(FILE);
}

This perl script just open, one per time, the files passed as parameters and read only the next-to-last character; if it is not a newline character, it just prints out the filename, else it does nothing.

Answer 5

Give this a try:

find . -type f -exec sh -c '[ -z "$(sed -n "\$p" "$1")" ]' _ {} \; -print

It will print filenames of files that end with a blank line. To print files that don't end in a blank line change the -z to -n.

Answer 6

If you have ripgrep installed:

rg -l '[^\n]\z'

That regular expression matches any character which is not a newline, and then the end of the file.