SHIFT(1P) POSIX Programmer's Manual SHIFT(1P)
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 repre-
sented by the numbers "$#" down to "$#-n+1" shall be unset, and the
parameter '#' is updated to reflect the new number of positional param-
eters.
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 con-
sidered 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 Electri-
cal 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.ker-
nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 SHIFT(1P)