strings [ -a ] [ -o ] [ -# ] [ -s ] [ fspec ... ]
The strings command searches one or more files for printable ASCII strings and writes them to standard output. If no files are specified, then the command searches standard input in binary mode.
The isprint() library function is used to test for printable ASCII characters. A sequence of printable characters must be terminated with a null, carriage return, or line feed character to be considered a valid string.