For each file given, GNU strings prints the printable character sequences that are at least 4 characters long (or the number given with the following options) and are followed by an unprintable character. By default, it only prints the strings from the initialized and loaded sections of object files; for other types of files, it prints the strings from the whole file.

strings is mainly useful for determining the contents of non-text files.
 

-a
--all
-
Do not scan only the initialized and loaded sections of object files; scan the whole files.
-f
--print-file-name
Print the name of the file before each string.
--help
Print a summary of the program usage on the standard output and exit.
-min-len
-n min-len
--bytes=min-len
Print sequences of characters that are at least min-len characters long, instead of the default 4.
-o
Like ‘-t o’. Some other versions of strings have ‘-o’ act like ‘-t d’. Since we can not be compatible with both ways, we simply chose one.
-t radix
--radix=radix
Print the offset within the file before each string. The single character argument specifies the radix of the offset—‘o’ for octal, ‘x’ for hexadecimal, or ‘d’ for decimal.
--target=bfdname
Specify an object code format other than your system’s default format. See Target selection for more information.
-v
--version
Print the program version number on the standard output and exit.