src/operand2sig.c

   1 /* operand2sig.c -- common function for parsing signal specifications
   2    Copyright (C) 2008-2024 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17 /* Extracted from kill.c/timeout.c by Pádraig Brady.
  18    FIXME: Move this to gnulib/str2sig.c */
  19
  20
  21 /* Convert OPERAND to a signal number.  Return the signal number, or -1 if
  22    unsuccessful.  */
  23
  24 #include <config.h>
  25 #include <stdio.h>
  26 #include <sys/types.h>
  27 #include <sys/wait.h>
  28
  29 #include "system.h"
  30 #include "quote.h"
  31 #include "sig2str.h"
  32 #include "operand2sig.h"
  33
  34 extern int
  35 operand2sig (char const *operand)
  36 {
  37   int signum;
  38
  39   if (ISDIGIT (*operand))
  40     {
  41       /* Note we don't put a limit on the maximum value passed,
  42          because we're checking shell $? values here, and ksh for
  43          example will add 256 to the signal value, thus being wider
  44          than the number of WEXITSTATUS bits.
  45          We could validate that values were not above say
  46          ((WEXITSTATUS (~0) << 1) + 1), which would cater for ksh.
  47          But some shells may use other adjustments in future to be
  48          (forward) compatible with systems that support
  49          wider exit status values as discussed at
  50          https://austingroupbugs.net/view.php?id=947  */
  51
  52       char *endp;
  53       long int l = (errno = 0, strtol (operand, &endp, 10));
  54       int i = l;
  55       signum = (operand == endp || *endp || errno || i != l ? -1 : i);
  56
  57       if (signum != -1)
  58         {
  59           /* Note AIX uses a different bit pattern for status returned
  60              from shell and wait(), so we can't use WTERMSIG etc. here.
  61              Also ksh returns 0xFF + signal number.  */
  62           signum &= signum >= 0xFF ? 0xFF : 0x7F;
  63         }
  64     }
  65   else
  66     {
  67       /* Convert signal to upper case in the C locale, not in the
  68          current locale.  Don't assume ASCII; it might be EBCDIC.  */
  69       char *upcased = xstrdup (operand);
  70       char *p;
  71       for (p = upcased; *p; p++)
  72         if (strchr ("abcdefghijklmnopqrstuvwxyz", *p))
  73           *p += 'A' - 'a';
  74
  75       /* Look for the signal name, possibly prefixed by "SIG",
  76          and possibly lowercased.  */
  77       if (!(str2sig (upcased, &signum) == 0
  78             || (upcased[0] == 'S' && upcased[1] == 'I' && upcased[2] == 'G'
  79                 && str2sig (upcased + 3, &signum) == 0)))
  80         signum = -1;
  81
  82       free (upcased);
  83     }
  84
  85   if (0 > signum || signum > SIGNUM_BOUND)
  86     {
  87       error (0, 0, _("%s: invalid signal"), quote (operand));
  88       return -1;
  89     }
  90
  91   return signum;
  92 }