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)
  40 {
  41         char next_ch = **endp;
  42
  43         /* errno is already set to ERANGE by strtoXXX if value overflowed */
  44         if (next_ch) {
  45                 /* "1234abcg" or out-of-range? */
  46                 if (isalnum(next_ch) || 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         if (!endp) endp = &endptr;
  61         *endp = (char*) arg;
  62
  63         /* strtoul("  -4200000000") returns 94967296, errno 0 (!) */
  64         /* I don't think that this is right. Preventing this... */
  65         //if (!isalnum(arg[0])) return ret_ERANGE();
  66         char first = (arg[0] != '-' ? arg[0] : arg[1]);
  67         if (!isalnum(first)) return ret_ERANGE();
  68
  69         /* not 100% correct for lib func, but convenient for the caller */
  70         errno = 0;
  71         v = strtoull(arg, endp, base);
  72         return handle_errors(v, endp);
  73 }
  74
  75 long long FAST_FUNC bb_strtoll(const char *arg, char **endp, int base)
  76 {
  77         unsigned long long v;
  78         char *endptr;
  79         char first;
  80
  81         if (!endp) endp = &endptr;
  82         *endp = (char*) arg;
  83
  84         /* Check for the weird "feature":
  85          * a "-" string is apparently a valid "number" for strto[u]l[l]!
  86          * It returns zero and errno is 0! :( */
  87         first = (arg[0] != '-' ? arg[0] : arg[1]);
  88         if (!isalnum(first)) return ret_ERANGE();
  89
  90         errno = 0;
  91         v = strtoll(arg, endp, base);
  92         return handle_errors(v, endp);
  93 }
  94
  95 #if ULONG_MAX != ULLONG_MAX
  96 unsigned long FAST_FUNC bb_strtoul(const char *arg, char **endp, int base)
  97 {
  98         unsigned long v;
  99         char *endptr;
 100
 101         if (!endp) endp = &endptr;
 102         *endp = (char*) arg;
 103
 104         if (!isalnum(arg[0])) return ret_ERANGE();
 105
 106         errno = 0;
 107         v = strtoul(arg, endp, base);
 108         return handle_errors(v, endp);
 109 }
 110
 111 long FAST_FUNC bb_strtol(const char *arg, char **endp, int base)
 112 {
 113         long v;
 114         char *endptr;
 115         char first;
 116
 117         if (!endp) endp = &endptr;
 118         *endp = (char*) arg;
 119
 120         first = (arg[0] != '-' ? arg[0] : arg[1]);
 121         if (!isalnum(first)) return ret_ERANGE();
 122
 123         errno = 0;
 124         v = strtol(arg, endp, base);
 125         return handle_errors(v, endp);
 126 }
 127 #endif
 128
 129 #if UINT_MAX != ULONG_MAX
 130 unsigned FAST_FUNC bb_strtou(const char *arg, char **endp, int base)
 131 {
 132         unsigned long v;
 133         char *endptr;
 134
 135         if (!endp) endp = &endptr;
 136         *endp = (char*) arg;
 137
 138         if (!isalnum(arg[0])) return ret_ERANGE();
 139
 140         errno = 0;
 141         v = strtoul(arg, endp, base);
 142         if (v > UINT_MAX) return ret_ERANGE();
 143         return handle_errors(v, endp);
 144 }
 145
 146 int FAST_FUNC bb_strtoi(const char *arg, char **endp, int base)
 147 {
 148         long v;
 149         char *endptr;
 150         char first;
 151
 152         if (!endp) endp = &endptr;
 153         *endp = (char*) arg;
 154
 155         first = (arg[0] != '-' ? arg[0] : arg[1]);
 156         if (!isalnum(first)) return ret_ERANGE();
 157
 158         errno = 0;
 159         v = strtol(arg, endp, base);
 160         if (v > INT_MAX) return ret_ERANGE();
 161         if (v < INT_MIN) return ret_ERANGE();
 162         return handle_errors(v, endp);
 163 }
 164 #endif