In computer software

Computer software

Computer software, or just software, is a collection of computer programs and related data that provide the instructions for telling a computer what to do and how to do it....

, strings is a program in Unix-like

Unix-like

A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification....

 operating system

Operating system

An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...

s that finds and prints text strings

String (computer science)

In formal languages, which are used in mathematical logic and theoretical computer science, a string is a finite sequence of symbols that are chosen from a set or alphabet....

 embedded in binary files such as executables.

It can be used on object files, and core dump

Core dump

In computing, a core dump consists of the recorded state of the working memory of a computer program at a specific time, generally when the program has terminated abnormally...

s.

Strings are recognized by looking for sequences of at least 4 (by default) printable characters terminating in a NUL character (that is, null-terminated string

Null-terminated string

In computer programming, a null-terminated string is a character string stored as an array containing the characters and terminated with a null character...

s). Some implementations provide options for determining what is recognized as a printable character, which is useful for finding non-ASCII and wide character text.

Common usage includes piping it to grep

Grep

grep is a command-line text-search utility originally written for Unix. The name comes from the ed command g/re/p...

and fold

Fold (Unix)

Fold is a Unix command used for making a file with long lines more readable on a limited width terminal. Most Linux terminals have a default screen width of 80, and therefore reading files with long lines could get annoying. The fold command puts a line feed every X characters if it doesn't...

or redirecting the output to a file

Computer file

A computer file is a block of arbitrary information, or resource for storing information, which is available to a computer program and is usually based on some kind of durable storage. A file is durable in the sense that it remains available for programs to use after the current program has finished...

.

It is part of the GNU Binary Utilities

GNU Binary Utilities

The GNU Binary Utilities, or binutils, comprise a collection of programming tools for the manipulation of object code in various object file formats. The current versions were originally written by programmers at Cygnus Solutions using the Binary File Descriptor library...

 (binutils), and has been ported to other operating systems including Microsoft Windows

Microsoft Windows

Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

.

Example

Using strings to print sequences of characters that are at least 8 characters long (this command prints the system's BIOS

BIOS

In IBM PC compatible computers, the basic input/output system , also known as the System BIOS or ROM BIOS , is a de facto standard defining a firmware interface....

 information; should be run as root):
dd if=/dev/mem bs=1k skip=768 count=256 2>/dev/null | strings -n 8 | less

See also

• cat
  Cat (Unix)
  The cat command is a standard Unix program used to concatenate and display files. The name is from catenate, a synonym of concatenate.- Specification :...
  
  
• GNU Debugger
  GNU Debugger
  The GNU Debugger, usually called just GDB and named gdb as an executable file, is the standard debugger for the GNU software system. It is a portable debugger that runs on many Unix-like systems and works for many programming languages, including Ada, C, C++, Objective-C, Free Pascal, Fortran, Java...
  
  
• strip
  Strip (Unix)
  In Unix and Unix-like operating systems, the strip program removes unnecessary information from executable binary programs and object files, thus potentially resulting in better performance and sometimes significantly less disk space usage...