How do you search for files containing dos line endings (CRLF) with grep on Linux?

Question

I want to search for files containing dos line endings with grep on Linux. Something like this:

grep -IUr --color '\r\n' .

The above seems to match for literal rn which is not what is desired.

The output of this will be piped through xargs into todos to convert crlf to lf like this

grep -IUrl --color '^M' . | xargs -ifile fromdos 'file'

Answer 1

Use Ctrl+V, Ctrl+M to enter a literal Carriage Return character into your grep string. So:

grep -IUr --color "^M"

will work - if the ^M there is a literal CR that you input as I suggested.

If you want the list of files, you want to add the -l option as well.

Explanation

• -I ignore binary files
• -U prevents grep to strip CR characters. By default it would do it if it decides it's a text file.
• -r read all files under each directory recursively.

Answer 2

grep probably isn't the tool you want for this. It will print a line for every matching line in every file. Unless you want to, say, run todos 10 times on a 10 line file, grep isn't the best way to go about it. Using find to run file on every file in the tree then grepping through that for "CRLF" will get you one line of output for each file which has dos style line endings:

find . -not -type d -exec file "{}" ";" | grep CRLF

will get you something like:

./1/dos1.txt: ASCII text, with CRLF line terminators
./2/dos2.txt: ASCII text, with CRLF line terminators
./dos.txt: ASCII text, with CRLF line terminators

Answer 3

grep -IUlr $'\r'

explainshell.com - grep -IUlr

Answer 4

If your version of grep supports -P (--perl-regexp) option, then

grep -lUP '\r$'

could be used.

Answer 5

# list files containing dos line endings (CRLF)

cr="$(printf "\r")"    # alternative to ctrl-V ctrl-M

grep -Ilsr "${cr}$" . 

grep -Ilsr $'\r$' .   # yet another & even shorter alternative

Answer 6

The query was search... I have a similar issue... somebody submitted mixed line endings into the version control, so now we have a bunch of files with 0x0d 0x0d 0x0a line endings. Note that

grep -P '\x0d\x0a'

finds all lines, whereas

grep -P '\x0d\x0d\x0a'

and

grep -P '\x0d\x0d'

finds no lines so there may be something "else" going on inside grep when it comes to line ending patterns... unfortunately for me!

Answer 7

If, like me, your minimalist unix doesn't include niceties like the file command, and backslashes in your grep expressions just don't cooperate, try this:

$ for file in `find . -type f` ; do
> dump $file | cut -c9-50 | egrep -m1 -q ' 0d| 0d'
> if [ $? -eq 0 ] ; then echo $file ; fi
> done

Modifications you may want to make to the above include:

• tweak the find command to locate only the files you want to scan
• change the dump command to od or whatever file dump utility you have
• confirm that the cut command includes both a leading and trailing space as well as just the hexadecimal character output from the dump utility
• limit the dump output to the first 1000 characters or so for efficiency

For example, something like this may work for you using od instead of dump:

 od -t x2 -N 1000 $file | cut -c8- | egrep -m1 -q ' 0d| 0d|0d$'

Answer 8

You can use file command in unix. It gives you the character encoding of the file along with line terminators.

$ file myfile
myfile: ISO-8859 text, with CRLF line terminators
$ file myfile | grep -ow CRLF
CRLF