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Elegant way to search for UTF-8 files with BOM?

For debugging purposes, I need to recursively search a directory for all files which start with a UTF-8 byte order mark (BOM). My current solution is a simple shell script:

find -type f |
while read file
do
    if [ "`head -c 3 -- "$file"`" == $'\xef\xbb\xbf' ]
    then
        echo "found BOM in: $file"
    fi
done

Or, if you prefer short, unreadable one-liners:

find -type f|while read file;do [ "`head -c3 -- "$file"`" == $'\xef\xbb\xbf' ] && echo "found BOM in: $file";done

It doesn't work with filenames that contain a line break, but such files are not to be expected anyway.

Is there any shorter or more elegant solution?

Are there any interesting text editors or macros for text editors?


A
Agostino

What about this one simple command which not just finds but clears the nasty BOM? :)

find . -type f -exec sed '1s/^\xEF\xBB\xBF//' -i {} \;

I love "find" :)

Warning The above will modify binary files which contain those three characters.

If you want just to show BOM files, use this one:

grep -rl $'\xEF\xBB\xBF' .

Incorrectly detects PDF with a BOM marker.. that's because it searches the whole document, not just the first line
Or with ack: "ack '\xEF\xBB\xBF'"
change the sed command to add a 1 before the leading 's' so it only applies to the first line
Use grep -rlI $'\xEF\xBB\xBF' . to ignore binary files.
Detects and modifies JPG and other binary files, as already said.
d
doppelgreener

The best and easiest way to do this on Windows:

Total Commander → go to project's root dir → find files (Alt + F7) → file types *.* → Find text "EF BB BF" → check 'Hex' checkbox → search

And you get the list :)


Nice, especially the use of my long time favorite Total commander, but unfortunately this suffers the same issue as many others: it searches all bytes in a fle, so many images etc are reported. This can be slightly improved by using RegEx instead of Hex and searching for "^\xEF\xBB\xBF" which will eliminate many images but still has files that have the BOM halfway through the file (although there should be few) and of course any binary files that happen to have an ascii newline charcode just beofre the BOM. Still, all images were gone in my test search.
A
Aron Griffis
find . -type f -print0 | xargs -0r awk '
    /^\xEF\xBB\xBF/ {print FILENAME}
    {nextfile}'

Most of the solutions given above test more than the first line of the file, even if some (such as Marcus's solution) then filter the results. This solution only tests the first line of each file so it should be a bit quicker.


Got is working with the following on Linux (RHEL6) - find . -type f -print0 | xargs -0 awk '/^\xEF\xBB\xBF/ {print FILENAME} {nextfile}'
How do I have to modify your code to fix these files after they were found?
C
CesarB

If you accept some false positives (in case there are non-text files, or in the unlikely case there is a ZWNBSP in the middle of a file), you can use grep:

fgrep -rl `echo -ne '\xef\xbb\xbf'` .

t
theory

You can use grep to find them and Perl to strip them out like so:

grep -rl $'\xEF\xBB\xBF' . | xargs perl -i -pe 's{\xEF\xBB\xBF}{}'

This one worked for me, the accepted answer didn't (I'm on a Mac)
M
Marcus Griep

I would use something like:

grep -orHbm1 "^`echo -ne '\xef\xbb\xbf'`" . | sed '/:0:/!d;s/:0:.*//'

Which will ensure that the BOM occurs starting at the first byte of the file.


P
Peter Mortensen

For a Windows user, see this (good PHP script for finding the BOM in your project).


The linked website shows: "Website Offline, No Cached Version Available".
same script is also available in github: github.com/emrahgunduz/BomCleaner
Thanks buddy, Your answer saved my day.
And a BOM Finder: github.com/svn2github/wikia/blob/master/extensions/FCKeditor/… (in case someone don't like the 'automatic' cleaning, or just wants to find the files with BOM)
m
mario

An overkill solution to this is phptags (not the vi tool with the same name), which specifically looks for PHP scripts:

phptags --warn ./

Will output something like:

./invalid.php: TRAILING whitespace ("?>\n")
./invalid.php: UTF-8 BOM alone ("\xEF\xBB\xBF")

And the --whitespace mode will automatically fix such issues (recursively, but asserts that it only rewrites .php scripts.)


P
Peter Mortensen

I used this to correct only JavaScript files:

find . -iname *.js -type f -exec sed 's/^\xEF\xBB\xBF//' -i.bak {} \; -exec rm {}.bak \;

J
Jonathan Wright
find -type f -print0 | xargs -0 grep -l `printf '^\xef\xbb\xbf'` | sed 's/^/found BOM in: /'

find -print0 puts a null \0 between each file name instead of using new lines

xargs -0 expects null separated arguments instead of line separated

grep -l lists the files which match the regex

The regex ^\xeff\xbb\xbf isn't entirely correct, as it will match non-BOMed UTF-8 files if they have zero width spaces at the start of a line


You still need a "head 1" in the pipe before the grep
M
Mike Dotterer

If you are looking for UTF files, the file command works. It will tell you what the encoding of the file is. If there are any non ASCII characters in there it will come up with UTF.

file *.php | grep UTF

That won't work recursively though. You can probably rig up some fancy command to make it recursive, but I just searched each level individually like the following, until I ran out of levels.

file */*.php | grep UTF