54

Is there any linux command to extracts all the ascii strings from an executable or other binary file? I suppose I could do it with a grep, but I remember hearing somewhere that such a command existed?

6 Answers 6

90

The command you are looking for is strings

Its name is quite self-explanatory, it retrieves any printable string from a given file.

man strings gives:

STRINGS(1)

NAME
strings - find the printable strings in a object, or other binary, file

SYNOPSIS
strings [ - ] [ -a ] [ -o ] [ -t format ] [ -number ] [ -n number ] [--] [file ...]

2
  • In some use cases, white space, including newlines, is considered "ascii". GNU strings option -w (--include-all-whitespace) might help in those cases. Jan 13, 2022 at 12:48
  • 1
    awesome! I didn't know such command existed. Now I can finally grep files containing a mixture of text and non-printable data. Jan 13, 2022 at 17:51
17

The strings command is the way to go for this particular type of problems. Sometimes you also have to pipe it out to grep.

For example:

strings somebinaryfile | grep textuwanttofind
5

The command does exist, and is called.... strings!

4

A problem with using strings is that you don't see surrounding non printables and you have to be careful with the minimum string length.

A problem using

od -c FILE
or
hexdump -C FILE
is that a sequence can be difficult to find if it wraps a line.

Something I like a lot for this is ZTreeWin running in WINE on Linux - you can do a lot with it but the searching in any file or editing binaries can be particularly useful.

The awesome ytree package is available for many Linux and Unix variants and has a good Hex dump view of any file but doesn't have the search that ZTreeWin (and its 16bit predecessor, XTree) have.

3

The od command can do this:

od -c *filename*
1
  • 3
    yeah, that does extract the ASCII characters, but it's not really the strings, per se. I think that 'strings' is more useful for the majority of cases.
    – user5336
    Aug 7, 2009 at 15:07
0

If strings is not available (like with git-bash on Windows) - try something like this:

  • tr -d -c '[:print:]\n'

Explanation: Delete (-d) all characters other than printable and newline.

Complement (-c): gives the opposite/inverse of the translate character list. In this case all non-printable non-newline characters.

Reference for the tr (translate) command: https://www.gnu.org/software/coreutils/manual/html_node/tr-invocation.html

Similar answer from Stack Overflow: https://stackoverflow.com/a/55360597/226625

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