# strings

## PROLOG



           This manual page is part of the POSIX Programmer's Manual.  The
           Linux implementation of this interface may differ (consult the
           corresponding Linux manual page for details of Linux behavior), or
           the interface may not be implemented on Linux.
    


## NAME



           strings — find printable strings in files
    


## SYNOPSIS



           strings **[** -a**] [** -t _format_**] [** -n _number_**] [**_file_...**]**
    


## DESCRIPTION



           The _strings_ utility shall look for printable strings in regular
           files and shall write those strings to standard output. A
           printable string is any sequence of four (by default) or more
           printable characters terminated by a <newline> or NUL character.
           Additional implementation-defined strings may be written; see
           _localedef_.
    
           If the first argument is **'-'** , the results are unspecified.
    


## OPTIONS



           The _strings_ utility shall conform to the Base Definitions volume
           of POSIX.1‐2017, _Section 12.2_ , _Utility Syntax Guidelines_ , except
           for the unspecified usage of **'-'**.
    
           The following options shall be supported:
    
           **-a** Scan files in their entirety. If **-a** is not specified, it
                     is implementation-defined what portion of each file is
                     scanned for strings.
    
           **-n** _number_ Specify the minimum string length, where the _number_
                     argument is a positive decimal integer. The default
                     shall be 4.
    
           **-t** _format_ Write each string preceded by its byte offset from the
                     start of the file. The format shall be dependent on the
                     single character used as the _format_ option-argument:
    
                     d     The offset shall be written in decimal.
    
                     o     The offset shall be written in octal.
    
                     x     The offset shall be written in hexadecimal.
    


## OPERANDS



           The following operand shall be supported:
    
           _file_      A pathname of a regular file to be used as input. If no
                     _file_ operand is specified, the _strings_ utility shall
                     read from the standard input.
    


## STDIN



           See the INPUT FILES section.
    


## INPUT FILES



           The input files named by the utility arguments or the standard
           input shall be regular files of any format.
    


## ENVIRONMENT VARIABLES



           The following environment variables shall affect the execution of
           _strings_ :
    
           _LANG_      Provide a default value for the internationalization
                     variables that are unset or null. (See the Base
                     Definitions volume of POSIX.1‐2017, _Section 8.2_ ,
                     _Internationalization Variables_ for the precedence of
                     internationalization variables used to determine the
                     values of locale categories.)
    
           _LC_ALL_    If set to a non-empty string value, override the values
                     of all the other internationalization variables.
    
           _LC_CTYPE_  Determine the locale for the interpretation of sequences
                     of bytes of text data as characters (for example,
                     single-byte as opposed to multi-byte characters in
                     arguments and input files) and to identify printable
                     strings.
    
           _LC_MESSAGES_
                     Determine the locale that should be used to affect the
                     format and contents of diagnostic messages written to
                     standard error.
    
           _NLSPATH_   Determine the location of message catalogs for the
                     processing of _LC_MESSAGES_.
    


## ASYNCHRONOUS EVENTS



           Default.
    


## STDOUT



           Strings found shall be written to the standard output, one per
           line.
    
           When the **-t** option is not specified, the format of the output
           shall be:
    
               "%s", <_string_ >
    
           With the **-t o** option, the format of the output shall be:
    
               "%o %s", <_byte offset_ >, <_string_ >
    
           With the **-t x** option, the format of the output shall be:
    
               "%x %s", <_byte offset_ >, <_string_ >
    
           With the **-t d** option, the format of the output shall be:
    
               "%d %s", <_byte offset_ >, <_string_ >
    


## STDERR



           The standard error shall be used only for diagnostic messages.
    


## OUTPUT FILES



           None.
    


## EXTENDED DESCRIPTION



           None.
    


## EXIT STATUS



           The following exit values shall be returned:
    
            0    Successful completion.
    
           >0    An error occurred.
    


## CONSEQUENCES OF ERRORS



           Default.
    
           _The following sections are informative._
    


## APPLICATION USAGE



           By default the data area (as opposed to the text, ``bss'', or
           header areas) of a binary executable file is scanned.
           Implementations document which areas are scanned.
    
           Some historical implementations do not require NUL or <newline>
           terminators for strings to permit those languages that do not use
           NUL as a string terminator to have their strings written.
    


## EXAMPLES



           None.
    


## RATIONALE



           Apart from rationalizing the option syntax and slight difficulties
           with object and executable binary files, _strings_ is specified to
           match historical practice closely. The **-a** and **-n** options were
           introduced to replace the non-conforming **-** and **-**_number_ options.
           These options are no longer specified by POSIX.1‐2008 but may be
           present in some implementations.
    
           The **-o** option historically means different things on different
           implementations. Some use it to mean ``_offset_ in decimal'', while
           others use it as ``_offset_ in octal''. Instead of trying to decide
           which way would be least objectionable, the **-t** option was added.
           It was originally named **-O** to mean ``offset'', but was changed to
           **-t** to be consistent with _od_.
    
           The ISO C standard function _isprint_() is restricted to a domain of
           **unsigned char**.  This volume of POSIX.1‐2017 requires
           implementations to write strings as defined by the current locale.
    


## FUTURE DIRECTIONS



           None.
    


* * *