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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-05 18:33:23 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-05 18:33:23 +0000 |
commit | 1d5cace9db9aef76f26b2d7ba54bbb76443b00b2 (patch) | |
tree | 314a15dd1aa103da13bdc83ba1d2105a290bc5ba /builtins/let.def | |
parent | Initial commit. (diff) | |
download | bash-upstream.tar.xz bash-upstream.zip |
Adding upstream version 5.0.upstream/5.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'builtins/let.def')
-rw-r--r-- | builtins/let.def | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/builtins/let.def b/builtins/let.def new file mode 100644 index 0000000..d090a45 --- /dev/null +++ b/builtins/let.def @@ -0,0 +1,131 @@ +This file is let.def, from which is created let.c. +It implements the builtin "let" in Bash. + +Copyright (C) 1987-2009 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/>. + +$BUILTIN let +$FUNCTION let_builtin +$PRODUCES let.c +$SHORT_DOC let arg [arg ...] +Evaluate arithmetic expressions. + +Evaluate each ARG as an arithmetic expression. Evaluation is done in +fixed-width integers with no check for overflow, though division by 0 +is trapped and flagged as an error. The following list of operators is +grouped into levels of equal-precedence operators. The levels are listed +in order of decreasing precedence. + + id++, id-- variable post-increment, post-decrement + ++id, --id variable pre-increment, pre-decrement + -, + unary minus, plus + !, ~ logical and bitwise negation + ** exponentiation + *, /, % multiplication, division, remainder + +, - addition, subtraction + <<, >> left and right bitwise shifts + <=, >=, <, > comparison + ==, != equality, inequality + & bitwise AND + ^ bitwise XOR + | bitwise OR + && logical AND + || logical OR + expr ? expr : expr + conditional operator + =, *=, /=, %=, + +=, -=, <<=, >>=, + &=, ^=, |= assignment + +Shell variables are allowed as operands. The name of the variable +is replaced by its value (coerced to a fixed-width integer) within +an expression. The variable need not have its integer attribute +turned on to be used in an expression. + +Operators are evaluated in order of precedence. Sub-expressions in +parentheses are evaluated first and may override the precedence +rules above. + +Exit Status: +If the last ARG evaluates to 0, let returns 1; let returns 0 otherwise. +$END + +#include <config.h> + +#if defined (HAVE_UNISTD_H) +# ifdef _MINIX +# include <sys/types.h> +# endif +# include <unistd.h> +#endif + +#include "../bashintl.h" + +#include "../shell.h" +#include "common.h" + +/* Arithmetic LET function. */ +int +let_builtin (list) + WORD_LIST *list; +{ + intmax_t ret; + int expok; + + CHECK_HELPOPT (list); + + /* Skip over leading `--' argument. */ + if (list && list->word && ISOPTION (list->word->word, '-')) + list = list->next; + + if (list == 0) + { + builtin_error (_("expression expected")); + return (EXECUTION_FAILURE); + } + + for (; list; list = list->next) + { + ret = evalexp (list->word->word, EXP_EXPANDED, &expok); + if (expok == 0) + return (EXECUTION_FAILURE); + } + + return ((ret == 0) ? EXECUTION_FAILURE : EXECUTION_SUCCESS); +} + +#ifdef INCLUDE_UNUSED +int +exp_builtin (list) + WORD_LIST *list; +{ + char *exp; + intmax_t ret; + int expok; + + if (list == 0) + { + builtin_error (_("expression expected")); + return (EXECUTION_FAILURE); + } + + exp = string_list (list); + ret = evalexp (exp, EXP_EXPANDED, &expok); + (void)free (exp); + return (((ret == 0) || (expok == 0)) ? EXECUTION_FAILURE : EXECUTION_SUCCESS); +} +#endif |