shift(1p) — Linux manual page

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

       shift — shift positional parameters

SYNOPSIS         top

       shift [n]

DESCRIPTION         top

       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         top

       None.

OPERANDS         top

       See the DESCRIPTION.

STDIN         top

       Not used.

INPUT FILES         top

       None.

ENVIRONMENT VARIABLES         top

       None.

ASYNCHRONOUS EVENTS         top

       Default.

STDOUT         top

       Not used.

STDERR         top

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES         top

       None.

EXTENDED DESCRIPTION         top

       None.

EXIT STATUS         top

       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         top

       Default.

       The following sections are informative.

APPLICATION USAGE         top

       None.

EXAMPLES         top

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

RATIONALE         top

       None.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       Section 2.14, Special Built-In Utilities

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                         SHIFT(1P)

HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH.