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Diffstat (limited to 'builtins/shift.def')
-rw-r--r-- | builtins/shift.def | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/builtins/shift.def b/builtins/shift.def new file mode 100644 index 0000000..4d8fed0 --- /dev/null +++ b/builtins/shift.def @@ -0,0 +1,95 @@ +This file is shift.def, from which is created shift.c. +It implements the builtin "shift" in Bash. + +Copyright (C) 1987, 1989, 1991 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 1, 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; see the file COPYING. If not, write to the Free Software +Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. + +$PRODUCES shift.c + +#if defined (HAVE_STRING_H) +# include <string.h> +#else /* !HAVE_STRING_H */ +# include <strings.h> +#endif /* !HAVE_STRING_H */ + +#include "../shell.h" + +$BUILTIN shift +$FUNCTION shift_builtin +$SHORT_DOC shift [n] +The positional parameters from $N+1 ... are renamed to $1 ... If N is +not given, it is assumed to be 1. +$END + +/* 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; +{ + int times, number; + WORD_LIST *args; + + times = get_numeric_arg (list); + + if (!times) + return (EXECUTION_SUCCESS); + + if (times < 0) + { + builtin_error ("shift count must be >= 0"); + return (EXECUTION_FAILURE); + } + + args = list_rest_of_args (); + number = list_length (args); + dispose_words (args); + + if (times > number) + { + builtin_error ("shift count must be <= $#"); + return (EXECUTION_FAILURE); + } + + while (times-- > 0) + { + register int count; + + if (dollar_vars[1]) + free (dollar_vars[1]); + + for (count = 1; count < 9; count++) + dollar_vars[count] = dollar_vars[count + 1]; + + if (rest_of_args) + { + WORD_LIST *temp = rest_of_args; + + dollar_vars[9] = savestring (temp->word->word); + rest_of_args = rest_of_args->next; + temp->next = (WORD_LIST *)NULL; + dispose_words (temp); + } + else + dollar_vars[9] = (char *)NULL; + } + + return (EXECUTION_SUCCESS); +} |