vga text output and libc expansion

[3sys] / sys1 / kern / src / libc / stdlib.c

diff --git a/sys1/kern/src/libc/stdlib.c b/sys1/kern/src/libc/stdlib.c
new file mode 100644 (file)
index 0000000..859372f
--- /dev/null
+++ b/sys1/kern/src/libc/stdlib.c
@@ -0,0 +1,193 @@
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <limits.h>
+
+int atoi(const char *str)
+{
+       return strtol(str, 0, 10);
+}
+
+long atol(const char *str)
+{
+       return strtol(str, 0, 10);
+}
+
+long strtol(const char *str, char **endp, int base)
+{
+       long acc = 0;
+       int sign = 1;
+       int valid = 0;
+       const char *start = str;
+
+       while(isspace(*str)) str++;
+
+       if(base == 0) {
+               if(str[0] == '0') {
+                       if(str[1] == 'x' || str[1] == 'X') {
+                               base = 16;
+                       } else {
+                               base = 8;
+                       }
+               } else {
+                       base = 10;
+               }
+       }
+
+       if(*str == '+') {
+               str++;
+       } else if(*str == '-') {
+               sign = -1;
+               str++;
+       }
+
+       while(*str) {
+               long val = LONG_MAX;
+               char c = tolower(*str);
+
+               if(isdigit(c)) {
+                       val = *str - '0';
+               } else if(c >= 'a' && c <= 'f') {
+                       val = 10 + c - 'a';
+               } else {
+                       break;
+               }
+               if(val >= base) {
+                       break;
+               }
+               valid = 1;
+
+               acc = acc * base + val;
+               str++;
+       }
+
+       if(endp) {
+               *endp = (char*)(valid ? str : start);
+       }
+
+       return sign > 0 ? acc : -acc;
+}
+
+void itoa(int val, char *buf, int base)
+{
+       static char rbuf[16];
+       char *ptr = rbuf;
+       int neg = 0;
+
+       if(val < 0) {
+               neg = 1;
+               val = -val;
+       }
+
+       if(val == 0) {
+               *ptr++ = '0';
+       }
+
+       while(val) {
+               int digit = val % base;
+               *ptr++ = digit < 10 ? (digit + '0') : (digit - 10 + 'a');
+               val /= base;
+       }
+
+       if(neg) {
+               *ptr++ = '-';
+       }
+
+       ptr--;
+
+       while(ptr >= rbuf) {
+               *buf++ = *ptr--;
+       }
+       *buf = 0;
+}
+
+void utoa(unsigned int val, char *buf, int base)
+{
+       static char rbuf[16];
+       char *ptr = rbuf;
+
+       if(val == 0) {
+               *ptr++ = '0';
+       }
+
+       while(val) {
+               unsigned int digit = val % base;
+               *ptr++ = digit < 10 ? (digit + '0') : (digit - 10 + 'a');
+               val /= base;
+       }
+
+       ptr--;
+
+       while(ptr >= rbuf) {
+               *buf++ = *ptr--;
+       }
+       *buf = 0;
+}
+
+#define QSORT_THRESHOLD        4
+#define ITEM(idx)      ((char*)arr + (idx) * itemsz)
+
+#define SWAP(p, q) \
+       do { \
+               int nn = itemsz; \
+               char *pp = (p); \
+               char *qq = (q); \
+               do { \
+                       char tmp = *pp; \
+                       *pp++ = *qq; \
+                       *qq++ = tmp; \
+               } while(--nn > 0); \
+       } while(0)
+
+static void ins_sort(void *arr, size_t count, size_t itemsz, int (*cmp)(const void*, const void*))
+{
+       int i;
+       char *it, *a, *b;
+
+       if(count <= 1) return;
+
+       it = (char*)arr + itemsz;
+       for(i=1; i<count; i++) {
+               a = it;
+               it += itemsz;
+               while(a > (char*)arr && cmp(a, (b = a - itemsz)) < 0) {
+                       SWAP(a, b);
+                       a -= itemsz;
+               }
+       }
+}
+
+void qsort(void *arr, size_t count, size_t itemsz, int (*cmp)(const void*, const void*))
+{
+       char *ma, *mb, *mc, *left, *right;
+       size_t sepidx, nleft, nright;
+
+       if(count <= 1) return;
+
+       if(count < QSORT_THRESHOLD) {
+               ins_sort(arr, count, itemsz, cmp);
+               return;
+       }
+
+       ma = arr;
+       mb = ITEM(count / 2);
+       mc = ITEM(count - 1);
+       if(cmp(ma, mb) < 0) SWAP(ma, mb);
+       if(cmp(mc, ma) < 0) SWAP(mc, ma);
+
+       left = ma + itemsz;
+       right = mc - itemsz;
+       for(;;) {
+               while(cmp(left, ma) < 0) left += itemsz;
+               while(cmp(ma, right) < 0) right -= itemsz;
+               if(left >= right) break;
+               SWAP(left, right);
+       }
+       SWAP(ma, right);
+       sepidx = (right - (char*)arr) / itemsz;
+       nleft = sepidx;
+       nright = count - nleft - 1;
+
+       qsort(ma, nleft, itemsz, cmp);
+       qsort(right + itemsz, nright, itemsz, cmp);
+}