Imported from ../bash-4.0-rc1.tar.gz.

[platform/upstream/bash.git] / builtins / let.def

diff --git a/builtins/let.def b/builtins/let.def
index fdb3a6f..2601fb9 100644 (file)
--- a/builtins/let.def
+++ b/builtins/let.def
@@ -1,44 +1,58 @@
 This file is let.def, from which is created let.c.
 It implements the builtin "let" in Bash.
 
-Copyright (C) 1987, 1989, 1991 Free Software Foundation, Inc.
+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 1, or (at your option) any later
-version.
+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.
+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.
+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 ...]
-Each ARG is an arithmetic expression to be evaluated.  Evaluation
-is done in long 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.
-
-       -               unary minus
-       !               logical NOT
-       * / %           multiplication, division, remainder
-       + -             addition, subtraction
-       <= >= < >       comparison
-       == !=           equality inequality
-       =               assignment
+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 long integer) within
+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.
 
@@ -46,32 +60,70 @@ Operators are evaluated in order of precedence.  Sub-expressions in
 parentheses are evaluated first and may override the precedence
 rules above.
 
-If the last ARG evaluates to 0, let returns 1; 0 is returned
-otherwise.
+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;
 {
-  long ret = 0L;
+  intmax_t ret;
+  int expok;
+
+  /* Skip over leading `--' argument. */
+  if (list && list->word && ISOPTION (list->word->word, '-'))
+    list = list->next;
 
-  if (!list)
+  if (list == 0)
     {
-      builtin_error ("argument (expression) expected");
+      builtin_error (_("expression expected"));
       return (EXECUTION_FAILURE);
     }
 
-  while (list)
+  for (; list; list = list->next)
     {
-      ret = evalexp (list->word->word);
-      list = list->next;
+      ret = evalexp (list->word->word, &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);
     }
 
-  if (ret == 0L)
-    return (EXECUTION_FAILURE);
-  else
-    return (EXECUTION_SUCCESS);
+  exp = string_list (list);
+  ret = evalexp (exp, &expok);
+  (void)free (exp);
+  return (((ret == 0) || (expok == 0)) ? EXECUTION_FAILURE : EXECUTION_SUCCESS);
 }
+#endif