restructuring

F0:F030,F042,F072/Snippets/readint.c

@@ -0,0 +1,77 @@
+char *omit_spaces(char *buf){
+    while(*buf){
+        if(*buf > ' ') break;
+        ++buf;
+    }
+    return buf;
+}
+
+// THERE'S NO OVERFLOW PROTECTION IN NUMBER READ PROCEDURES!
+// read decimal number
+static char *getdec(char *buf, uint32_t *N){
+    uint32_t num = 0;
+    while(*buf){
+        char c = *buf;
+        if(c < '0' || c > '9'){
+            break;
+        }
+        num *= 10;
+        num += c - '0';
+        ++buf;
+    }
+    *N = num;
+    return buf;
+}
+// read hexadecimal number (without 0x prefix!)
+static char *gethex(char *buf, uint32_t *N){
+    uint32_t num = 0;
+    while(*buf){
+        char c = *buf;
+        uint8_t M = 0;
+        if(c >= '0' && c <= '9'){
+            M = '0';
+        }else if(c >= 'A' && c <= 'F'){
+            M = 'A' - 10;
+        }else if(c >= 'a' && c <= 'f'){
+            M = 'a' - 10;
+        }
+        if(M){
+            num <<= 4;
+            num += c - M;
+        }else{
+            break;
+        }
+        ++buf;
+    }
+    *N = num;
+    return buf;
+}
+// read binary number (without 0b prefix!)
+static char *getbin(char *buf, uint32_t *N){
+    uint32_t num = 0;
+    while(*buf){
+        char c = *buf;
+        if(c < '0' || c > '1'){
+            break;
+        }
+        num <<= 1;
+        if(c == '1') num |= 1;
+        ++buf;
+    }
+    *N = num;
+    return buf;
+}
+
+/**
+ * @brief getnum - read uint32_t from string (dec, hex or bin: 127, 0x7f, 0b1111111)
+ * @param buf - buffer with number and so on
+ * @param N   - the number read
+ * @return pointer to first non-number symbol in buf (if it is == buf, there's no number)
+ */
+char *getnum(char *txt, uint32_t *N){
+    if(*txt == '0'){
+        if(txt[1] == 'x' || txt[1] == 'X') return gethex(txt+2, N);
+        if(txt[1] == 'b' || txt[1] == 'B') return getbin(txt+2, N);
+    }
+    return getdec(txt, N);
+}