strings(1p) — Linux manual page

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.1‐2017, 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         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.1‐2017, 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         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.1‐2017 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.1‐2017, 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 1003.1-2017, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The
       Open Group Base Specifications Issue 7, 2018 Edition, Copyright
       (C) 2018 by the Institute of Electrical and Electronics
       Engineers, Inc and The Open Group.  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.opengroup.org/unix/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               2017                       STRINGS(1P)