How can I find encoding of a file via a script on Linux?

file -bi <file name>

If you like to do this for a bunch of files

for f in `find | egrep -v Eliminate`; do echo "$f" ' -- ' `file -bi "$f"` ; done

uchardet - An encoding detector library ported from Mozilla.

Usage:

~> uchardet file.java
UTF-8

Various Linux distributions (Debian, Ubuntu, openSUSE, Pacman, etc.) provide binaries.

In Debian you can also use: encguess:

$ encguess test.txt
test.txt  US-ASCII

As it is a perl script, it can be installed on most systems, by installing perl or the script as standalone, in case perl has already been installed.

$ dpkg -S /usr/bin/encguess
perl: /usr/bin/encguess

Then there are several other implementations in various languages going under the name uchardet, that you can find some additional versions in the README here.

Then there is the classic file command. Perhaps with the most comprehensive magic file in existence, since it's been around as long as the C-language. You use it like this:

file -b --mime-encoding -P bytes=1024 xxxx.md

where:

• -b: Do not prepend filenames to output lines (brief mode).
• --mime-encoding: To output only the element of the mime type strings.
• -P bytes=1024: Set the bytes parameter to read a maximum number of 1024 bytes.
  (You can also use the encoding parameter.) *

* Caveat: Due to character-set byte-alignment, the results may depend on the number of bytes read. (Which is why Teocci wraps the command in a function to first read the total number of characters in the file, using wc. If you get a result of binary for a readable file, it is obviously wrong.)

Finally, there is also a native powershell function in this gist.

To convert encoding from ISO 8859-1 to ASCII:

iconv -f ISO_8859-1 -t ASCII filename.txt

Here is an example script using file -I and iconv which works on Mac OS X.

For your question, you need to use mv instead of iconv:

#!/bin/bash
# 2016-02-08
# check encoding and convert files
for f in *.java
do
  encoding=`file -I $f | cut -f 2 -d";" | cut -f 2 -d=`
  case $encoding in
    iso-8859-1)
    iconv -f iso8859-1 -t utf-8 $f > $f.utf8
    mv $f.utf8 $f
    ;;
  esac
done

With Python, you can use the chardet module.

It is really hard to determine if it is ISO 8859-1. If you have a text with only 7-bit characters that could also be ISO 8859-1, but you don't know. If you have 8-bit characters then the upper region characters exist in order encodings as well. Therefore you would have to use a dictionary to get a better guess which word it is and determine from there which letter it must be. Finally, if you detect that it might be UTF-8 then you are sure it is not ISO 8859-1.

Encoding is one of the hardest things to do, because you never know if nothing is telling you.

With this command:

for f in `find .`; do echo `file -i "$f"`; done

you can list all files in a directory and subdirectories and the corresponding encoding.

If files have a space in the name, use:

IFS=$'\n'
for f in `find .`; do echo `file -i "$f"`; done

Remember it'll change your current Bash session interpreter for "spaces".

In PHP you can check it like below:

Specifying the encoding list explicitly:

php -r "echo 'probably : ' . mb_detect_encoding(file_get_contents('myfile.txt'), 'UTF-8, ASCII, JIS, EUC-JP, SJIS, iso-8859-1') . PHP_EOL;"

More accurate "mb_list_encodings":

php -r "echo 'probably : ' . mb_detect_encoding(file_get_contents('myfile.txt'), mb_list_encodings()) . PHP_EOL;"

Here in the first example, you can see that I used a list of encodings (detect list order) that might be matching. To have a more accurate result, you can use all possible encodings via: mb_list_encodings()

Note the mb_* functions require php-mbstring:

apt-get install php-mbstring

This is not something you can do in a foolproof way. One possibility would be to examine every character in the file to ensure that it doesn't contain any characters in the ranges 0x00 - 0x1f or 0x7f -0x9f but, as I said, this may be true for any number of files, including at least one other variant of ISO 8859.

Another possibility is to look for specific words in the file in all of the languages supported and see if you can find them.

So, for example, find the equivalent of the English "and", "but", "to", "of" and so on in all the supported languages of ISO 8859-1 and see if they have a large number of occurrences within the file.

I'm not talking about literal translation such as:

English   French
-------   ------
of        de, du
and       et
the       le, la, les

although that's possible. I'm talking about common words in the target language (for all I know, Icelandic has no word for "and" - you'd probably have to use their word for "fish" [sorry that's a little stereotypical. I didn't mean any offense, just illustrating a point]).

I know you're interested in a more general answer, but what's good in ASCII is usually good in other encodings. Here is a Python one-liner to determine if standard input is ASCII. (I'm pretty sure this works in Python 2, but I've only tested it on Python 3.)

python -c 'from sys import exit,stdin;exit()if 128>max(c for l in open(stdin.fileno(),"b") for c in l) else exit("Not ASCII")' < myfile.txt

If you're talking about XML files (ISO-8859-1), the XML declaration inside them specifies the encoding: <?xml version="1.0" encoding="ISO-8859-1" ?> So, you can use regular expressions (e.g., with Perl) to check every file for such specification.

More information can be found here: How to Determine Text File Encoding.

I was working in a project that requires cross-platform support and I encounter many problems related with the file encoding.

I made this script to convert all to utf-8:

#!/bin/bash
## Retrieve the encoding of files and convert them
for f  `find "$1" -regextype posix-egrep -regex ".*\.(cpp|h)$"`; do
  echo "file: $f"
  ## Reads the entire file and get the enconding
  bytes_to_scan=$(wc -c < $f)
  encoding=`file -b --mime-encoding -P bytes=$bytes_to_scan $f`
  case $encoding in
    iso-8859-1 | euc-kr)
    iconv -f euc-kr -t utf-8 $f > $f.utf8
    mv $f.utf8 $f
    ;;
  esac
done

I used a hack to read the entire file and estimate the file encoding using file -b --mime-encoding -P bytes=$bytes_to_scan $f

The file command is not able to do this.

– Both yes and no. The following will do the job, but isn't completely reliable : ¹

file -i * | grep -v iso-8859-1

It returns the non-ISO-8859-1 encoded files in the current directory – the ones you want to move.

I am using the following script to

1. Find all files that match FILTER with SRC_ENCODING
2. Create a backup of them
3. Convert them to DST_ENCODING
4. (optional) Remove the backups

#!/bin/bash -xe

SRC_ENCODING="iso-8859-1"
DST_ENCODING="utf-8"
FILTER="*.java"

echo "Find all files that match the encoding $SRC_ENCODING and filter $FILTER"
FOUND_FILES=$(find . -iname "$FILTER" -exec file -i {} \; | grep "$SRC_ENCODING" | grep -Eo '^.*\.java')

for FILE in $FOUND_FILES ; do
    ORIGINAL_FILE="$FILE.$SRC_ENCODING.bkp"
    echo "Backup original file to $ORIGINAL_FILE"
    mv "$FILE" "$ORIGINAL_FILE"

    echo "converting $FILE from $SRC_ENCODING to $DST_ENCODING"
    iconv -f "$SRC_ENCODING" -t "$DST_ENCODING" "$ORIGINAL_FILE" -o "$FILE"
done

echo "Deleting backups"
find . -iname "*.$SRC_ENCODING.bkp" -exec rm {} \;

You can extract encoding of a single file with the file command. I have a sample.html file with:

$ file sample.html 

sample.html: HTML document, UTF-8 Unicode text, with very long lines

$ file -b sample.html

HTML document, UTF-8 Unicode text, with very long lines

$ file -bi sample.html

text/html; charset=utf-8

$ file -bi sample.html  | awk -F'=' '{print $2 }'

utf-8

In Cygwin, this looks like it works for me:

find -type f -name "<FILENAME_GLOB>" | while read <VAR>; do (file -i "$<VAR>"); done

Example:

find -type f -name "*.txt" | while read file; do (file -i "$file"); done

You could pipe that to AWK and create an iconv command to convert everything to UTF-8, from any source encoding supported by iconv.

Example:

find -type f -name "*.txt" | while read file; do (file -i "$file"); done | awk -F[:=] '{print "iconv -f "$3" -t utf8 \""$1"\" > \""$1"_utf8\""}' | bash

With Perl, use Encode::Detect.