builtins/caller.def

   1 This file is caller.def, from which is created caller.c.  It implements the
   2 builtin "caller" in Bash.
   3
   4 Copyright (C) 2002-2008 Rocky Bernstein for Free Software Foundation, Inc.
   5 Copyright (C) 2008-2013 Free Software Foundation, Inc.
   6
   7 This file is part of GNU Bash, the Bourne Again SHell.
   8
   9 Bash is free software: you can redistribute it and/or modify
  10 it under the terms of the GNU General Public License as published by
  11 the Free Software Foundation, either version 3 of the License, or
  12 (at your option) any later version.
  13
  14 Bash is distributed in the hope that it will be useful,
  15 but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 GNU General Public License for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with Bash.  If not, see <http://www.gnu.org/licenses/>.
  21
  22 $PRODUCES caller.c
  23
  24 $BUILTIN caller
  25 $FUNCTION caller_builtin
  26 $DEPENDS_ON DEBUGGER
  27 $SHORT_DOC caller [expr]
  28 Return the context of the current subroutine call.
  29
  30 Without EXPR, returns "$line $filename".  With EXPR, returns
  31 "$line $subroutine $filename"; this extra information can be used to
  32 provide a stack trace.
  33
  34 The value of EXPR indicates how many call frames to go back before the
  35 current one; the top frame is frame 0.
  36
  37 Exit Status:
  38 Returns 0 unless the shell is not executing a shell function or EXPR
  39 is invalid.
  40 $END
  41
  42 #include <config.h>
  43 #include <stdio.h>
  44 #include "chartypes.h"
  45 #include "bashtypes.h"
  46
  47 #if defined (HAVE_UNISTD_H)
  48 #  ifdef _MINIX
  49 #    include <sys/types.h>
  50 #  endif
  51 #  include <unistd.h>
  52 #endif
  53
  54 #include <errno.h>
  55
  56 #include "../bashintl.h"
  57
  58 #include "../shell.h"
  59 #include "common.h"
  60 #include "builtext.h"
  61 #include "bashgetopt.h"
  62
  63 #ifdef LOADABLE_BUILTIN
  64 #  include "builtins.h"
  65 #endif
  66
  67 #if !defined (errno)
  68 extern int errno;
  69 #endif /* !errno */
  70
  71 int
  72 caller_builtin (list)
  73      WORD_LIST *list;
  74 {
  75 #if !defined (ARRAY_VARS)
  76   printf ("1 NULL\n");
  77   return (EXECUTION_FAILURE);
  78 #else
  79   SHELL_VAR *funcname_v, *bash_source_v, *bash_lineno_v;
  80   ARRAY *funcname_a, *bash_source_a, *bash_lineno_a;
  81   char *funcname_s, *source_s, *lineno_s;
  82   intmax_t num;
  83
  84   CHECK_HELPOPT (list);
  85
  86   GET_ARRAY_FROM_VAR ("FUNCNAME", funcname_v, funcname_a);
  87   GET_ARRAY_FROM_VAR ("BASH_SOURCE", bash_source_v, bash_source_a);
  88   GET_ARRAY_FROM_VAR ("BASH_LINENO", bash_lineno_v, bash_lineno_a);
  89
  90   if (bash_lineno_a == 0 || array_empty (bash_lineno_a))
  91     return (EXECUTION_FAILURE);
  92
  93   if (bash_source_a == 0 || array_empty (bash_source_a))
  94     return (EXECUTION_FAILURE);
  95
  96  if (no_options (list))
  97     return (EX_USAGE);
  98   list = loptend;       /* skip over possible `--' */
  99
 100   /* If there is no argument list, then give short form: line filename. */
 101   if (list == 0)
 102     {
 103       lineno_s = array_reference (bash_lineno_a, 0);
 104       source_s = array_reference (bash_source_a, 1);
 105       printf("%s %s\n", lineno_s ? lineno_s : "NULL", source_s ? source_s : "NULL");
 106       return (EXECUTION_SUCCESS);
 107     }
 108
 109   if (funcname_a == 0 || array_empty (funcname_a))
 110     return (EXECUTION_FAILURE);
 111
 112   if (legal_number (list->word->word, &num))
 113     {
 114       lineno_s = array_reference (bash_lineno_a, num);
 115       source_s = array_reference (bash_source_a, num+1);
 116       funcname_s = array_reference (funcname_a, num+1);
 117
 118       if (lineno_s == NULL|| source_s == NULL || funcname_s == NULL)
 119         return (EXECUTION_FAILURE);
 120
 121       printf("%s %s %s\n", lineno_s, funcname_s, source_s);
 122     }
 123   else
 124     {
 125       sh_invalidnum (list->word->word);
 126       builtin_usage ();
 127       return (EX_USAGE);
 128     }
 129
 130   return (EXECUTION_SUCCESS);
 131 #endif
 132 }
 133
 134 #ifdef LOADABLE_BUILTIN
 135 static char *caller_doc[] = {
 136 N_("Returns the context of the current subroutine call.\n\
 137     \n\
 138     Without EXPR, returns "$line $filename".  With EXPR, returns\n\
 139     "$line $subroutine $filename"; this extra information can be used to\n\
 140     provide a stack trace.\n\
 141     \n\
 142     The value of EXPR indicates how many call frames to go back before the\n\
 143     current one; the top frame is frame 0."),
 144   (char *)NULL
 145 };
 146
 147 struct builtin caller_struct = {
 148         "caller",
 149         caller_builtin,
 150         BUILTIN_ENABLED,
 151         caller_doc,
 152         "caller [EXPR]",
 153         0
 154 };
 155
 156 #endif /* LOADABLE_BUILTIN */