WebSVN – HelenOS-historic – Diff – /uspace/trunk/libc/generic/string.c

  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 #include <string.h>
+#include <unistd.h>
+#include <ctype.h>
+#include <limits.h>
 /* Dummy implementation of mem/ functions */
 void * memset(void *s, int c, size_t n)
+{
     while (n--)
         *(odst++) = *(os++);
     return dest;
+}
+/** Count the number of characters in the string, not including terminating 0.
+ * @param str string
+ * @return number of characters in string.
+ */
 size_t strlen(const char *str)
+{
     size_t counter = 0;
     while (str[counter] != 0) {
         counter++;
+    }
     return counter;
+}
+/** Return pointer to the first occurence of character c in string
+ * @param str scanned string
+ * @param c searched character (taken as one byte)
+ * @return pointer to the matched character or NULL if it is not found in given string.
+ */
+char *strchr(const char *str, int c)
+{
+    while (*str != '\0') {
+        if (*str == (char)c)
+            return (char *)str;
+        str++;
+    }
+    return NULL;
+}
+/** Return pointer to the last occurence of character c in string
+ * @param str scanned string
+ * @param c searched character (taken as one byte)
+ * @return pointer to the matched character or NULL if it is not found in given string.
+ */
+char *strrchr(const char *str, int c)
+{
+    char *retval = NULL;
+    while (*str != '\0') {
+        if (*str == (char)c)
+            retval = (char *)str;
+        str++;
+    }
+    return (char *)retval;
+}
+/** Convert string to a number.
+ * Core of strtol and strtoul functions.
+ * @param nptr pointer to string
+ * @param endptr if not NULL, function stores here pointer to the first invalid character
+ * @param base zero or number between 2 and 36 inclusive
+ * @param sgn its set to 1 if minus found
+ * @return result of conversion.
+ */
+static unsigned long _strtoul(const char *nptr, char **endptr, int base, char *sgn)
+{
+    unsigned char c;
+    unsigned long result = 0;
+    unsigned long a, b;
+    const char *str = nptr;
+    const char *tmpptr;
+    while (isspace(*str))
+        str++;
+    if (*str == '-') {
+        *sgn = 1;
+        ++str;
+    } else if (*str == '+')
+        ++str;
+    if (base) {
+        if ((base == 1) || (base > 36)) {
+            /* FIXME: set errno to EINVAL */
+            return 0;
+        }
+        if ((base == 16) && (*str == '0') && ((str[1] == 'x') || (str[1] == 'X'))) {
+            str += 2;
+        }
+    } else {
+        base = 10;
+        if (*str == '0') {
+            base = 8;
+            if ((str[1] == 'X') || (str[1] == 'x'))  {
+                base = 16;
+                str += 2;
+            }
+        }
+    }
+    tmpptr = str;
+    while (*str) {
+        c = *str;
+        c = ( c >= 'a'? c-'a'+10:(c >= 'A'?c-'A'+10:(c <= '9'?c-'0':0xff)));
+        if (c > base) {
+            break;
+        }
+        a = (result & 0xff) * base + c;
+        b = (result >> 8) * base + (a >> 8);
+        if (b > (ULONG_MAX >> 8)) {
+            /* overflow */
+            /* FIXME: errno = ERANGE*/
+            return ULONG_MAX;
+        }
+        result = (b << 8) + (a & 0xff);
+        ++str;
+    }
+    if (str == tmpptr) {
+        /* no number was found => first invalid character is the first character of the string */
+        /* FIXME: set errno to EINVAL */
+        str = nptr;
+        result = 0;
+    }
+    if (endptr)
+        *endptr = (char *)str;
+    if (nptr == str) {
+        /*FIXME: errno = EINVAL*/
+        return 0;
+    }
+    return result;
+}
+/** Convert initial part of string to long int according to given base.
+ * The number may begin with an arbitrary number of whitespaces followed by optional sign (`+' or `-').
+ * If the base is 0 or 16, the prefix `0x' may be inserted and the number will be taken as hexadecimal one.
+ * If the base is 0 and the number begin with a zero, number will be taken as octal one (as with base 8).
+ * Otherwise the base 0 is taken as decimal.
+ * @param nptr pointer to string
+ * @param endptr if not NULL, function stores here pointer to the first invalid character
+ * @param base zero or number between 2 and 36 inclusive
+ * @return result of conversion.
+ */
+long int strtol(const char *nptr, char **endptr, int base)
+{
+    char sgn = 0;
+    unsigned long number = 0;
+    number = _strtoul(nptr, endptr, base, &sgn);
+    if (number > LONG_MAX) {
+        if ((sgn) && (number == (unsigned long)(LONG_MAX) + 1)) {
+            /* FIXME: set 0 to errno */
+            return number;
+        }
+        /* FIXME: set ERANGE to errno */
+        return (sgn?LONG_MIN:LONG_MAX);
+    }
+    return (sgn?-number:number);
+}
+/** Convert initial part of string to unsigned long according to given base.
+ * The number may begin with an arbitrary number of whitespaces followed by optional sign (`+' or `-').
+ * If the base is 0 or 16, the prefix `0x' may be inserted and the number will be taken as hexadecimal one.
+ * If the base is 0 and the number begin with a zero, number will be taken as octal one (as with base 8).
+ * Otherwise the base 0 is taken as decimal.
+ * @param nptr pointer to string
+ * @param endptr if not NULL, function stores here pointer to the first invalid character
+ * @param base zero or number between 2 and 36 inclusive
+ * @return result of conversion.
+ */
+unsigned long strtoul(const char *nptr, char **endptr, int base)
+{
+    char sgn = 0;
+    unsigned long number = 0;
+    number = _strtoul(nptr, endptr, base, &sgn);
+    return (sgn?-number:number);
+}

Subversion Repositories HelenOS-historic

(root)/uspace/trunk/libc/generic/string.c – Rev 1197 → 1314