Changeset 30a5470 in mainline

Timestamp:

2010-04-18T00:19:51Z (15 years ago)

Author:

Martin Decky <martin@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

c39a103

Parents:

88dea9d

Message:

string to integer conversion routines

Location:

kernel/generic

Files:

• include/str.h (modified) (1 diff)
• src/lib/str.c (modified) (2 diffs)

kernel/generic/include/str.h

@@ -97 +97 @@
 extern bool wstr_remove(wchar_t *str, size_t pos);
 
+extern int str_uint64(const char *, char **, unsigned int, bool, uint64_t *);
+
 #endif
 

kernel/generic/src/lib/str.c

@@ -110 +110 @@
 #include <align.h>
 #include <debug.h>
+#include <macros.h>
 
 /** Byte mask consisting of lowest @n bits (out of 8) */
@@ -760 +761 @@
 }
 
+/** Convert string to uint64_t (internal variant).
+ *
+ * @param nptr   Pointer to string.
+ * @param endptr Pointer to the first invalid character is stored here.
+ * @param base   Zero or number between 2 and 36 inclusive.
+ * @param neg    Indication of unary minus is stored here.
+ * @apram result Result of the conversion.
+ *
+ * @return EOK if conversion was successful.
+ *
+ */
+static int str_uint(const char *nptr, char **endptr, unsigned int base,
+    bool *neg, uint64_t *result)
+{
+        ASSERT(endptr != NULL);
+        ASSERT(neg != NULL);
+        ASSERT(result != NULL);
+        
+        *neg = false;
+        const char *str = nptr;
+        
+        /* Ignore leading whitespace */
+        while (isspace(*str))
+                str++;
+        
+        if (*str == '-') {
+                *neg = true;
+                str++;
+        } else if (*str == '+')
+                str++;
+        
+        if (base == 0) {
+                /* Decode base if not specified */
+                base = 10;
+                
+                if (*str == '0') {
+                        base = 8;
+                        str++;
+                        
+                        switch (*str) {
+                        case 'b':
+                        case 'B':
+                                base = 2;
+                                str++;
+                                break;
+                        case 'o':
+                        case 'O':
+                                base = 8;
+                                str++;
+                                break;
+                        case 'd':
+                        case 'D':
+                        case 't':
+                        case 'T':
+                                base = 10;
+                                str++;
+                                break;
+                        case 'x':
+                        case 'X':
+                                base = 16;
+                                str++;
+                                break;
+                        }
+                }
+        } else {
+                /* Check base range */
+                if ((base < 2) || (base > 36)) {
+                        *endptr = (char *) str;
+                        return EINVAL;
+                }
+        }
+        
+        *result = 0;
+        const char *startstr = str;
+        
+        while (*str != 0) {
+                unsigned int digit;
+                
+                if ((*str >= 'a') && (*str <= 'z'))
+                        digit = *str - 'a' + 10;
+                else if ((*str >= 'A') && (*str <= 'Z'))
+                        digit = *str - 'A' + 10;
+                else if ((*str >= '0') && (*str <= '9'))
+                        digit = *str - '0';
+                else
+                        break;
+                
+                if (digit >= base)
+                        break;
+                
+                uint64_t prev = *result;
+                *result = (*result) * base + digit;
+                
+                if (*result < prev) {
+                        /* Overflow */
+                        *endptr = (char *) str;
+                        return EOVERFLOW;
+                }
+                
+                str++;
+        }
+        
+        if (str == startstr) {
+                /*
+                 * No digits were decoded => first invalid character is
+                 * the first character of the string.
+                 */
+                str = nptr;
+        }
+        
+        *endptr = (char *) str;
+        
+        if (str == nptr)
+                return EINVAL;
+        
+        return EOK;
+}
+
+/** Convert string to uint64_t.
+ *
+ * @param nptr   Pointer to string.
+ * @param endptr If not NULL, pointer to the first invalid character
+ *               is stored here.
+ * @param base   Zero or number between 2 and 36 inclusive.
+ * @param strict Do not allow any trailing characters.
+ * @apram result Result of the conversion.
+ *
+ * @return EOK if conversion was successful.
+ *
+ */
+int str_uint64(const char *nptr, char **endptr, unsigned int base,
+    bool strict, uint64_t *result)
+{
+        ASSERT(result != NULL);
+        
+        bool neg;
+        char *lendptr;
+        int ret = str_uint(nptr, &lendptr, base, &neg, result);
+        
+        if (endptr != NULL)
+                *endptr = (char *) lendptr;
+        
+        if (ret != EOK)
+                return ret;
+        
+        /* Do not allow negative values */
+        if (neg)
+                return EINVAL;
+        
+        /* Check whether we are at the end of
+           the string in strict mode */
+        if ((strict) && (*lendptr != 0))
+                return EINVAL;
+        
+        return EOK;
+}
+
 /** @}
  */