[c_book] ex-1-19 reverses one line at time

c_book/1-ch/data/ex-1-19

@@ -0,0 +1,2 @@
+this will be messed up
+siht daer ot elba eb dlouhs uoy

c_book/1-ch/exercises/ex-1-19.c

@@ -0,0 +1,62 @@
+#include<stdio.h>
+#define MAX 1000 
+
+/*
+ * Reverses lines one line at a time. 
+ *
+ * Prints results to stdout. 
+ * */
+
+int getnextline(char[], int);
+void reverse(char[], int); 
+
+int getnextline(char s[], int limit)
+{
+   int i, c;
+
+   for (i = 0; i < limit - 1 && (c = getchar()) != EOF && c != '\n'; ++i) {
+     s[i] = c;
+   } 
+
+   if (c == '\n') {
+     s[i] = '\n';
+     ++i;   
+  }
+
+   s[i] = '\0';
+
+   reverse(s, i);
+   return i;
+}
+
+// removes trailing ' ' and \t 
+void reverse(char s[], int len) 
+{
+  int h, left, right;
+  left = 0;
+  right = len - 2;
+
+  while (right > left) {
+    h = s[left];
+    s[left] = s[right];
+    s[right] = h;
+    ++left;
+    --right;
+  }
+} 
+
+
+int main(void)
+{
+  int len;
+  char s[MAX];
+  // while we have a line 
+  while (getnextline(s, MAX) != 0) {
+    printf("%s", s);
+  }
+
+
+  return 0;
+}
+
+