PROLOG | NAME | SYNOPSIS | DESCRIPTION | OPTIONS | OPERANDS | STDIN | INPUT FILES | ENVIRONMENT VARIABLES | ASYNCHRONOUS EVENTS | STDOUT | STDERR | OUTPUT FILES | EXTENDED DESCRIPTION | EXIT STATUS | CONSEQUENCES OF ERRORS | APPLICATION USAGE | EXAMPLES | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

STRINGS(1P)               POSIX Programmer's Manual              STRINGS(1P)

PROLOG         top

       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         top

       strings — find printable strings in files

SYNOPSIS         top

       strings [−a] [−t format] [−n number] [file...]

DESCRIPTION         top

       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         top

       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         top

       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         top

       See the INPUT FILES section.

INPUT FILES         top

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

ENVIRONMENT VARIABLES         top

       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         top

       Default.

STDOUT         top

       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         top

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES         top

       None.

EXTENDED DESCRIPTION         top

       None.

EXIT STATUS         top

       The following exit values shall be returned:

        0    Successful completion.

       >0    An error occurred.

CONSEQUENCES OF ERRORS         top

       Default.

       The following sections are informative.

APPLICATION USAGE         top

       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         top

       None.

RATIONALE         top

       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         top

       None.

SEE ALSO         top

       localedef(1p), nm(1p)

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

COPYRIGHT         top

       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 .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the
       source files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                 2013                         STRINGS(1P)