Initial Commit

OU4/is_connected_help_functions.c

@@ -0,0 +1,88 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <stdbool.h>
+
+#define MAXNODENAME 40
+#define BUFSIZE 400
+
+/**
+ * @brief Find position of first non-whitespace character.
+ *
+ * @param s - string to search.
+ * @return int - Returns the position of the first non-whitespace character, or -1 if not found.
+ */
+int first_non_white_space(const char *s)
+{
+    int i = 0; // Start at first char.
+
+    // Advance as long as we're loooking at white-space until we hit EOL.
+    while (s[i] && isspace(s[i])) {
+        i++;
+    }
+    // We found a non-whitespace char.
+    if (s[i]) {
+        // It was a proper characted. Return its position.
+        return i;
+    } else {
+        // It was the null terminator. Return fail.
+        return -1;
+    }
+}
+
+/**
+ * @brief Determine if the string is blank.
+ *
+ * @param s - string to search.
+ * @return true if the line contains only whitespace chars.
+ * @return false if the line contains at least one non-whitespace char.
+ */
+
+bool line_is_blank(const char *s)
+{
+    // Line is blank if it only contained white-space chars.
+    return first_non_white_space(s) < 0;
+}
+
+/**
+ * @brief Determina if the string is a comment line.
+ *
+ * @param s - string to search.
+ * @return true if the line is a comment line.
+ * @return false if the line is not a comment line.
+ *
+ * A comment line has a hash sign '#' as the first non-whitespace char on the line.
+ */
+bool line_is_comment(const char *s)
+{
+    int i = first_non_white_space(s);
+    return (i >= 0 && s[i] == '#');
+}
+
+/**
+ * @brief Extract node names from a line from the map file.
+ *
+ * @param buf - Input buffer.
+ * @param n1 - Output buffer for the first node name. Must be at least MAXNODENAME+1 long.
+ * @param n2 - Ditto for the second node name.
+ * @return int - Returns the number of correctly parsed node names. If the return value is 2, both n1
+ * and n2 contain node names. If the return value is less than 2, parsing of at least one node name
+ * failed, in which case the content of n1 and n2 are undefined.
+ */
+int parse_map_line(const char *buf, char *n1, char *n2)
+{
+    // Create a format string the will do the work.
+    char fmt[20];
+    // This will generate the format string " %40s %40s" if MAXNODENAME is 40.
+    snprintf(fmt, sizeof(fmt), " %%%ds %%%ds", MAXNODENAME, MAXNODENAME);
+
+    // sscanf does all the necessary parsing.
+    // Node names must be separated by whitespace.
+    // Whitespace before the first node name is allowed.
+    // Anything after the second node name is ignored.
+    int n = sscanf(buf, fmt, n1, n2);
+
+    // The return value from sscanf contains the number of properly parsed format codes, i.e. the
+    // number of node names.
+    return n;
+}