strings (Unix)

Not to be confused with string (computing).

strings

The strings command
Written in	C
Operating system	Unix, Unix-like, Plan 9, Inferno
Platform	Cross-platform
Type	Command
License	Plan 9: MIT License

strings is a shell command that searches a file for printable character strings and writes them to standard output.

The command can be useful for analyzing the information in a binary file. By definition, a binary file contains data that is not printable text yet a binary file often does contain some printable character text – often in relatively short sequences distributed throughout the file. These portions of the binary file can be informative as to what the file contains overall. For a text file, a file containing all printable characters, the command prints the entire file content, and therefore, provides no utility over more commonly used file output commands such as cat.

The command searches for sequences of printable characters that end with a NUL character but ignores any sequence that is less than a specified length or 4 characters by default. Some implementations provide options for determining what is recognized as a printable character, which is useful for finding non-ASCII and wide character text. By default, it only selects strings from the initialized and loaded sections of an object file. For other types of files, it selects strings from the whole file.

The command is available in Unix, Plan 9, Inferno, and Unix-like operating systems. It is part of the GNU Binary Utilities (binutils), and has been implemented to other operating systems including Windows.

Example

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

• GNU Debugger – Source-level debugger
• List of POSIX commands
• Paste (Unix) – Shell command for joining files horizontally
• Strip (Unix) – Shell command for removing non-essential information from executable code files

External links

• strings – Shell and Utilities Reference, The Single UNIX Specification, Version 5 from The Open Group
• strings(1) – Plan 9 Programmer's Manual, Volume 1
• strings(1) – Inferno General commands Manual