How to check if the file is a binary file and read all the files which are not?

Question

How can I know if a file is a binary file?

For example, compiled c file.

I want to read all files from some directory, but I want ignore binary files.

Answer 1

Try the following command-line:

file "$FILE" | grep -vq 'ASCII' && echo "$FILE is binary"

Answer 2

You can do this also by leveraging the diff command. Check this answer:

https://unix.stackexchange.com/questions/275516/is-there-a-convenient-way-to-classify-files-as-binary-or-text#answer-402870

Answer 3

grep

Assuming binary means file containing non-printable characters (excluding blank characters such as spaces, tabs or new line characters), this may work (both BSD and GNU):

$ grep '[^[:print:][:blank:]]' file && echo Binary || echo Text

^{Note: GNU grep will report file containing only NULL characters as text, but it would work correctly on BSD version.}

^{For more examples, see: How do I grep for all non-ASCII characters.}

Answer 4

Use utility file, sample usage:

 $ file /bin/bash
 /bin/bash: Mach-O universal binary with 2 architectures
 /bin/bash (for architecture x86_64):   Mach-O 64-bit executable x86_64
 /bin/bash (for architecture i386): Mach-O executable i386

 $ file /etc/passwd
 /etc/passwd: ASCII English text

 $ file code.c
 code.c: ASCII c program text

file manual page

Answer 5

Use Perl’s built-in -T file test operator, preferably after ascertaining that it is a plain file using the -f file test operator:

$ perl -le 'for (@ARGV) { print if -f && -T }' \
    getwinsz.c a.out /etc/termcap /bin /bin/cat \
    /dev/tty /usr/share/zoneinfo/UTC /etc/motd
getwinsz.c
/etc/termcap
/etc/motd

Here’s the complement of that set:

$ perl -le 'for (@ARGV) { print unless -f && -T }' \
    getwinsz.c a.out /etc/termcap /bin /bin/cat \
    /dev/tty /usr/share/zoneinfo/UTC /etc/motd
a.out
/bin
/bin/cat
/dev/tty
/usr/share/zoneinfo/UTC

Answer 6

Going off Bach's suggestion, I think --mime-encoding is the best flag to get something reliable from file.

file --mime-encoding [FILES ...] | grep -v '\bbinary$'

will print the files that file believes have a non-binary encoding. You can pipe this output through cut -d: -f1 to trim the : encoding if you just want the filenames.

---

Caveat: as @yugr reports below .doc files report an encoding of application/mswordbinary. This looks to me like a bug - the mime type is erroneously being concatenated with the encoding.

$ for flag in --mime --mime-type --mime-encoding; do
    echo "$flag"
    file "$flag" /tmp/example.{doc{,x},png,txt}
  done
--mime
/tmp/example.doc:  application/msword; charset=binary
/tmp/example.docx: application/vnd.openxmlformats-officedocument.wordprocessingml.document; charset=binary
/tmp/example.png:  image/png; charset=binary
/tmp/example.txt:  text/plain; charset=us-ascii
--mime-type
/tmp/example.doc:  application/msword
/tmp/example.docx: application/vnd.openxmlformats-officedocument.wordprocessingml.document
/tmp/example.png:  image/png
/tmp/example.txt:  text/plain
--mime-encoding
/tmp/example.doc:  application/mswordbinary
/tmp/example.docx: binary
/tmp/example.png:  binary
/tmp/example.txt:  us-ascii