Line data    Source code

       1             : This file is break.def, from which is created break.c.
       2             : It implements the builtins "break" and "continue" in Bash.
       3             : 
       4             : Copyright (C) 1987-2009 Free Software Foundation, Inc.
       5             : 
       6             : This file is part of GNU Bash, the Bourne Again SHell.
       7             : 
       8             : Bash is free software: you can redistribute it and/or modify
       9             : it under the terms of the GNU General Public License as published by
      10             : the Free Software Foundation, either version 3 of the License, or
      11             : (at your option) any later version.
      12             : 
      13             : Bash is distributed in the hope that it will be useful,
      14             : but WITHOUT ANY WARRANTY; without even the implied warranty of
      15             : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      16             : GNU General Public License for more details.
      17             : 
      18             : You should have received a copy of the GNU General Public License
      19             : along with Bash.  If not, see <http://www.gnu.org/licenses/>.
      20             : 
      21             : $PRODUCES break.c
      22             : 
      23             : $BUILTIN break
      24             : $FUNCTION break_builtin
      25             : $SHORT_DOC break [n]
      26             : Exit for, while, or until loops.
      27             : 
      28             : Exit a FOR, WHILE or UNTIL loop.  If N is specified, break N enclosing
      29             : loops.
      30             : 
      31             : Exit Status:
      32             : The exit status is 0 unless N is not greater than or equal to 1.
      33             : $END
      34             : #include <config.h>
      35             : 
      36             : #if defined (HAVE_UNISTD_H)
      37             : #  ifdef _MINIX
      38             : #    include <sys/types.h>
      39             : #  endif
      40             : #  include <unistd.h>
      41             : #endif
      42             : 
      43             : #include "../bashintl.h"
      44             : 
      45             : #include "../shell.h"
      46             : #include "common.h"
      47             : 
      48             : extern char *this_command_name;
      49             : extern int posixly_correct;
      50             : 
      51             : static int check_loop_level __P((void));
      52             : 
      53             : /* The depth of while's and until's. */
      54             : int loop_level = 0;
      55             : 
      56             : /* Non-zero when a "break" instruction is encountered. */
      57             : int breaking = 0;
      58             : 
      59             : /* Non-zero when we have encountered a continue instruction. */
      60             : int continuing = 0;
      61             : 
      62             : /* Set up to break x levels, where x defaults to 1, but can be specified
      63             :    as the first argument. */
      64             : int
      65          66 : break_builtin (list)
      66             :      WORD_LIST *list;
      67             : {
      68          66 :   intmax_t newbreak;
      69             : 
      70          66 :   CHECK_HELPOPT (list);
      71             : 
      72          66 :   if (check_loop_level () == 0)
      73             :     return (EXECUTION_SUCCESS);
      74             : 
      75           0 :   (void)get_numeric_arg (list, 1, &newbreak);
      76             : 
      77           0 :   if (newbreak <= 0)
      78             :     {
      79           0 :       sh_erange (list->word->word, _("loop count"));
      80           0 :       breaking = loop_level;
      81           0 :       return (EXECUTION_FAILURE);
      82             :     }
      83             : 
      84           0 :   if (newbreak > loop_level)
      85           0 :     newbreak = loop_level;
      86             : 
      87           0 :   breaking = newbreak;
      88             : 
      89           0 :   return (EXECUTION_SUCCESS);
      90             : }
      91             : 
      92             : $BUILTIN continue
      93             : $FUNCTION continue_builtin
      94             : $SHORT_DOC continue [n]
      95             : Resume for, while, or until loops.
      96             : 
      97             : Resumes the next iteration of the enclosing FOR, WHILE or UNTIL loop.
      98             : If N is specified, resumes the Nth enclosing loop.
      99             : 
     100             : Exit Status:
     101             : The exit status is 0 unless N is not greater than or equal to 1.
     102             : $END
     103             : 
     104             : /* Set up to continue x levels, where x defaults to 1, but can be specified
     105             :    as the first argument. */
     106             : int
     107          75 : continue_builtin (list)
     108             :      WORD_LIST *list;
     109             : {
     110          75 :   intmax_t newcont;
     111             : 
     112          75 :   CHECK_HELPOPT (list);
     113             : 
     114          75 :   if (check_loop_level () == 0)
     115             :     return (EXECUTION_SUCCESS);
     116             : 
     117           0 :   (void)get_numeric_arg (list, 1, &newcont);
     118             : 
     119           0 :   if (newcont <= 0)
     120             :     {
     121           0 :       sh_erange (list->word->word, _("loop count"));
     122           0 :       breaking = loop_level;
     123           0 :       return (EXECUTION_FAILURE);
     124             :     }
     125             : 
     126           0 :   if (newcont > loop_level)
     127           0 :     newcont = loop_level;
     128             : 
     129           0 :   continuing = newcont;
     130             : 
     131           0 :   return (EXECUTION_SUCCESS);
     132             : }
     133             : 
     134             : /* Return non-zero if a break or continue command would be okay.
     135             :    Print an error message if break or continue is meaningless here. */
     136             : static int
     137         141 : check_loop_level ()
     138             : {
     139             : #if defined (BREAK_COMPLAINS)
     140         141 :   if (loop_level == 0 && posixly_correct == 0)
     141         141 :     builtin_error (_("only meaningful in a `for', `while', or `until' loop"));
     142             : #endif /* BREAK_COMPLAINS */
     143             : 
     144         141 :   return (loop_level);
     145             : }