release/src/router/busybox/libbb/bb_strtonum.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Utility routines.
   4  *
   5  * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
   6  *
   7  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   8  */
   9
  10 #include "libbb.h"
  11
  12 /* On exit: errno = 0 only if there was non-empty, '\0' terminated value
  13  * errno = EINVAL if value was not '\0' terminated, but otherwise ok
  14  *    Return value is still valid, caller should just check whether end[0]
  15  *    is a valid terminating char for particular case. OTOH, if caller
  16  *    requires '\0' terminated input, [s]he can just check errno == 0.
  17  * errno = ERANGE if value had alphanumeric terminating char ("1234abcg").
  18  * errno = ERANGE if value is out of range, missing, etc.
  19  * errno = ERANGE if value had minus sign for strtouXX (even "-0" is not ok )
  20  *    return value is all-ones in this case.
  21  *
  22  * Test code:
  23  * char *endptr;
  24  * const char *minus = "-";
  25  * errno = 0;
  26  * bb_strtoi(minus, &endptr, 0); // must set ERANGE
  27  * printf("minus:%p endptr:%p errno:%d EINVAL:%d\n", minus, endptr, errno, EINVAL);
  28  * errno = 0;
  29  * bb_strtoi("-0-", &endptr, 0); // must set EINVAL and point to second '-'
  30  * printf("endptr[0]:%c errno:%d EINVAL:%d\n", endptr[0], errno, EINVAL);
  31  */
  32
  33 static unsigned long long ret_ERANGE(void)
  34 {
  35         errno = ERANGE; /* this ain't as small as it looks (on glibc) */
  36         return ULLONG_MAX;
  37 }
  38
  39 static unsigned long long handle_errors(unsigned long long v, char **endp, char *endptr)
  40 {
  41         if (endp) *endp = endptr;
  42
  43         /* errno is already set to ERANGE by strtoXXX if value overflowed */
  44         if (endptr[0]) {
  45                 /* "1234abcg" or out-of-range? */
  46                 if (isalnum(endptr[0]) || errno)
  47                         return ret_ERANGE();
  48                 /* good number, just suspicious terminator */
  49                 errno = EINVAL;
  50         }
  51         return v;
  52 }
  53
  54
  55 unsigned long long FAST_FUNC bb_strtoull(const char *arg, char **endp, int base)
  56 {
  57         unsigned long long v;
  58         char *endptr;
  59
  60         /* strtoul("  -4200000000") returns 94967296, errno 0 (!) */
  61         /* I don't think that this is right. Preventing this... */
  62         //if (!isalnum(arg[0])) return ret_ERANGE();
  63         char first = (arg[0] != '-' ? arg[0] : arg[1]);
  64         if (!isalnum(first)) return ret_ERANGE();
  65
  66         /* not 100% correct for lib func, but convenient for the caller */
  67         errno = 0;
  68         v = strtoull(arg, &endptr, base);
  69         return handle_errors(v, endp, endptr);
  70 }
  71
  72 long long FAST_FUNC bb_strtoll(const char *arg, char **endp, int base)
  73 {
  74         unsigned long long v;
  75         char *endptr;
  76
  77         /* Check for the weird "feature":
  78          * a "-" string is apparently a valid "number" for strto[u]l[l]!
  79          * It returns zero and errno is 0! :( */
  80         char first = (arg[0] != '-' ? arg[0] : arg[1]);
  81         if (!isalnum(first)) return ret_ERANGE();
  82
  83         errno = 0;
  84         v = strtoll(arg, &endptr, base);
  85         return handle_errors(v, endp, endptr);
  86 }
  87
  88 #if ULONG_MAX != ULLONG_MAX
  89 unsigned long FAST_FUNC bb_strtoul(const char *arg, char **endp, int base)
  90 {
  91         unsigned long v;
  92         char *endptr;
  93
  94         char first = (arg[0] != '-' ? arg[0] : arg[1]);
  95         if (!isalnum(first)) return ret_ERANGE();
  96
  97         errno = 0;
  98         v = strtoul(arg, &endptr, base);
  99         return handle_errors(v, endp, endptr);
 100 }
 101
 102 long FAST_FUNC bb_strtol(const char *arg, char **endp, int base)
 103 {
 104         long v;
 105         char *endptr;
 106
 107         char first = (arg[0] != '-' ? arg[0] : arg[1]);
 108         if (!isalnum(first)) return ret_ERANGE();
 109
 110         errno = 0;
 111         v = strtol(arg, &endptr, base);
 112         return handle_errors(v, endp, endptr);
 113 }
 114 #endif
 115
 116 #if UINT_MAX != ULONG_MAX
 117 unsigned FAST_FUNC bb_strtou(const char *arg, char **endp, int base)
 118 {
 119         unsigned long v;
 120         char *endptr;
 121
 122         char first = (arg[0] != '-' ? arg[0] : arg[1]);
 123         if (!isalnum(first)) return ret_ERANGE();
 124
 125         errno = 0;
 126         v = strtoul(arg, &endptr, base);
 127         if (v > UINT_MAX) return ret_ERANGE();
 128         return handle_errors(v, endp, endptr);
 129 }
 130
 131 int FAST_FUNC bb_strtoi(const char *arg, char **endp, int base)
 132 {
 133         long v;
 134         char *endptr;
 135
 136         char first = (arg[0] != '-' ? arg[0] : arg[1]);
 137         if (!isalnum(first)) return ret_ERANGE();
 138
 139         errno = 0;
 140         v = strtol(arg, &endptr, base);
 141         if (v > INT_MAX) return ret_ERANGE();
 142         if (v < INT_MIN) return ret_ERANGE();
 143         return handle_errors(v, endp, endptr);
 144 }
 145 #endif