Add doc, signature, indentation

conversions/c_atoi_str_to_integer.c

@@ -1,8 +1,27 @@
+/**
+ * \file
+ * \brief Recoding the original atoi function in stdlib.h 
+ * \author [Krishna Vedala](https://github.com/kvedala)
+ *
+ * The function convert a string passed to an integer 
+ */
 #include <stdio.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
 
-// recoding the original atoi function in stdlib.h
-int	c_atoi(char *str)
+/**
+ * the function take a string and return an integer
+ * \param[out] str pointer to a char address
+ */
+int c_atoi(const char *str)
 {
+    /**
+    * i is a counter
+    * sign hold the sign (negative or positive)
+    * value hold the current value by default set to 0
+    * prev hold the previous value for managing the overflow
+    */
     int     i;
     int     sign;
     long    value;
@@ -11,18 +30,22 @@ int	c_atoi(char *str)
     i = 0;
     sign = 1;
     value = 0;
-	// skip wait spaces
+
+    /* skipping the spaces */
     while (((str[i] <= 13 && str[i] >= 9) || str[i] == 32) && str[i] != '\0')
         i++;
-	// store the sign
+
+    /* store the sign if it is negative sign */
     if (str[i] == '-' || str[i] == '+')
         (str[i++] == '-') ? sign = -1 : 1;
-	// convert char by char to an int value
+
+    /* converting char by char to a numeric value */
     while (str[i] >= 48 && str[i] <= 57 && str[i] != '\0')
     {
         prev = value;
         value = value * 10 + sign * (str[i] - '0');
-		// manage the overflow
+
+        /* managing the overflow */
         if (sign == 1 && prev > value)
             return (-1);
         else if (sign == -1 && prev < value)
@@ -32,9 +55,33 @@ int	c_atoi(char *str)
     return (value);	
 }
 
-
-int	main()
+/**
+ * test the function implementation
+ */
+int test_c_atoi()
 {
-	// Test
-	printf("%d\n", c_atoi("-234"));
+    printf("<<<< TEST FUNCTION >>>>\n");
+    assert(c_atoi("123") == atoi("123"));
+    assert(c_atoi("-123") == atoi("-123"));
+    assert(c_atoi("") == atoi(""));
+    assert(c_atoi("-h23") == atoi("-h23"));
+    assert(c_atoi("         23") == atoi("         23"));
+    assert(c_atoi("999999999999") == atoi("999999999999"));
+    printf("<<<< TEST DONE >>>>\n");
+}
+
+
+/**
+ * the main function take one argument of type char*
+ * example : ./program 123
+ */
+int	main(int argc, char **argv)
+{
+    if (argc == 2)
+    {
+        printf("Your number + 5 is %d\n", c_atoi(argv[1]) + 5);
+        return (0);
+    }
+    printf("wrong number of parmeters\n");
+    return (1);
 }