shift

SHIFT(1POSIX)              POSIX Programmer's Manual             SHIFT(1POSIX)



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
       shift — shift positional parameters

SYNOPSIS
       shift [n]

DESCRIPTION
       The positional parameters shall be shifted. Positional parameter 1
       shall be assigned the value of parameter (1+n), parameter 2 shall be
       assigned the value of parameter (2+n), and so on. The parameters
       represented by the numbers "$#" down to "$#−n+1" shall be unset, and
       the parameter '#' is updated to reflect the new number of positional
       parameters.

       The value n shall be an unsigned decimal integer less than or equal to
       the value of the special parameter '#'.  If n is not given, it shall be
       assumed to be 1. If n is 0, the positional and special parameters are
       not changed.

OPTIONS
       None.

OPERANDS
       See the DESCRIPTION.

STDIN
       Not used.

INPUT FILES
       None.

ENVIRONMENT VARIABLES
       None.

ASYNCHRONOUS EVENTS
       Default.

STDOUT
       Not used.

STDERR
       The standard error shall be used only for diagnostic messages.

OUTPUT FILES
       None.

EXTENDED DESCRIPTION
       None.

EXIT STATUS
       If the n operand is invalid or is greater than "$#", this may be
       considered a syntax error and a non-interactive shell may exit; if the
       shell does not exit in this case, a non-zero exit status shall be
       returned. Otherwise, zero shall be returned.

CONSEQUENCES OF ERRORS
       Default.

       The following sections are informative.

APPLICATION USAGE
       None.

EXAMPLES
       $ set a b c d e
       $ shift 2
       $ echo $*
       c d e

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       Section 2.14, Special Built-In Utilities

COPYRIGHT
       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                        SHIFT(1POSIX)