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-rw-r--r--stage3/string.c56
1 files changed, 56 insertions, 0 deletions
diff --git a/stage3/string.c b/stage3/string.c
new file mode 100644
index 0000000..ff4bfc3
--- /dev/null
+++ b/stage3/string.c
@@ -0,0 +1,56 @@
+#include "string.h"
+
+usize find_char(const char *str, char chr)
+{
+ usize ret = 0;
+ while (*str != chr && *str != '\0')
+ str++, ret++;
+ return ret;
+}
+
+u64 parse_num(u8 **str, u8 base, isize size)
+{
+ u64 x = 0;
+
+ while (size-- != 0) {
+ u8 c = **str;
+
+ u64 d;
+ if (c >= '0' && c <= '9')
+ d = c - '0';
+ else if (c >= 'a' && c <= 'z')
+ d = c - 'a';
+ else if (c >= 'A' && c <= 'z')
+ d = c - 'A';
+ else
+ return x;
+
+ if (d >= base)
+ return x;
+
+ (*str)++;
+ x = x * base + d;
+ }
+
+ return x;
+}
+
+usize strlen(const char *str)
+{
+ return find_char(str, '\0');
+}
+
+int strcmp(const char *p1, const char *p2)
+{
+ while (*p1 == *p2 && *p1 != '\0')
+ p1++, p2++;
+ return *p1 - *p2;
+}
+
+int strncmp(const char *p1, const char *p2, usize size)
+{
+ for (usize i = 0; i < size; i++)
+ if (p1[i] != p2[i])
+ return p1[i]-p2[i];
+ return 0;
+}