illumos-port-bash/builtins/shift.def

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Modula-2

This file is shift.def, from which is created shift.c.
It implements the builtin "shift" in Bash.
Copyright (C) 1987-2020 Free Software Foundation, Inc.
This file is part of GNU Bash, the Bourne Again SHell.
Bash is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Bash is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Bash. If not, see <http://www.gnu.org/licenses/>.
$PRODUCES shift.c
#include <config.h>
#if defined (HAVE_UNISTD_H)
# ifdef _MINIX
# include <sys/types.h>
# endif
# include <unistd.h>
#endif
#include "../bashansi.h"
#include "../bashintl.h"
#include "../shell.h"
#include "common.h"
$BUILTIN shift
$FUNCTION shift_builtin
$SHORT_DOC shift [n]
Shift positional parameters.
Rename the positional parameters $N+1,$N+2 ... to $1,$2 ... If N is
not given, it is assumed to be 1.
Exit Status:
Returns success unless N is negative or greater than $#.
$END
int print_shift_error;
/* Shift the arguments ``left''. Shift DOLLAR_VARS down then take one
off of REST_OF_ARGS and place it into DOLLAR_VARS[9]. If LIST has
anything in it, it is a number which says where to start the
shifting. Return > 0 if `times' > $#, otherwise 0. */
int
shift_builtin (list)
WORD_LIST *list;
{
intmax_t times;
int itimes, nargs;
CHECK_HELPOPT (list);
if (get_numeric_arg (list, 0, &times) == 0)
return (EXECUTION_FAILURE);
if (times == 0)
return (EXECUTION_SUCCESS);
else if (times < 0)
{
sh_erange (list ? list->word->word : NULL, _("shift count"));
return (EXECUTION_FAILURE);
}
nargs = number_of_args ();
if (times > nargs)
{
if (print_shift_error)
sh_erange (list ? list->word->word : NULL, _("shift count"));
return (EXECUTION_FAILURE);
}
else if (times == nargs)
clear_dollar_vars ();
else
shift_args (itimes = times);
invalidate_cached_quoted_dollar_at ();
return (EXECUTION_SUCCESS);
}