xenial (1) strings.1posix.gz

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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.1‐2008, 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.1‐2008, 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.1‐2008 requires implementations to write strings as defined by the current locale.

FUTURE DIRECTIONS

       None.

SEE ALSO

       localedef, nm

       The Base Definitions volume of POSIX.1‐2008, Chapter 8,  Environment  Variables,  Section  12.2,  Utility
       Syntax Guidelines

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2013 Edition,
       Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open  Group  Base
       Specifications  Issue 7, Copyright (C) 2013 by the Institute of Electrical and Electronics Engineers, Inc
       and The Open Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In  the  event
       of  any  discrepancy between this version and the original IEEE and The Open Group Standard, the original
       IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at
       http://www.unix.org/online.html .

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