Cleaning code and provide minimal libc

1 files changed, 29 insertions, 0 deletions

diff --git a/src/libc/string.c b/src/libc/string.c
new file mode 100644
index 0000000..93a9e63
--- /dev/null
+++ b/src/libc/string.c
@@ -0,0 +1,29 @@
+#include "string.h"
+#include "math.h"
+
+void itoa(int i, char *a){
+    // Check if lower than 0
+    char neg=0;
+    if(i<0){
+        neg=1;
+        i=-i;
+        a[0]='-';
+    }
+
+    // Count number of digits
+    int len=1;
+    while(i/pow(10,len)>=1)
+    {
+        len++;
+    }
+
+    // Build string
+    int max_pow=len-1;
+    for(int j=0;j<=max_pow;j++){
+        int cur_pow=pow(10,max_pow-j);
+        char digit=i/cur_pow;
+        a[j+neg]='0'+digit;
+        i=i-digit*cur_pow; // Remove first digits (most significant)
+    }
+    a[len+neg]='\0';
+}
\ No newline at end of file