From 1f7068ac3281c0651c876d99612432a36c298f90 Mon Sep 17 00:00:00 2001
From: zlg <zlg@zlg.space>
Date: Wed, 9 Jan 2013 01:10:15 -0600
Subject: Solve Exercise 1-22: wordwrap

* Removed unnecessary get_line() function in 1-17
* Corrected grammar in README, added an acknowledgement
---
 1-22_wordwrap.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 75 insertions(+)
 create mode 100644 1-22_wordwrap.c

(limited to '1-22_wordwrap.c')

diff --git a/1-22_wordwrap.c b/1-22_wordwrap.c
new file mode 100644
index 0000000..5e17b50
--- /dev/null
+++ b/1-22_wordwrap.c
@@ -0,0 +1,75 @@
+#include <stdio.h>
+
+/* The C Programming Language: 2nd Edition
+ * Exercise 1-22:
+ * "Write a program to 'fold' long input lines into two or more shorter lines
+ * after the last non-blank character that occurs before the n-th column of
+ * input. Make sure your program does something intelligent with very long
+ * lines, and if there are no blanks or tabs before the specified column."
+ *
+ * So... Quite a hefty requirement. In a nutshell, our goal is to create sane
+ * hard-wrapping. This is a common function in text editors, and it's
+ * important to get it right or the results are wonky.
+ *
+ *
+ * TODO: get_line() is not fully correct. When it hits a \t, it counts it as
+ * one character and has no concept of display count. I'll fix this later on.
+ */
+
+// For tradition's sake, let's wrap at 80 columns
+#define MAXLEN 80
+
+char data[MAXLEN];
+int i, j, k;
+
+int get_line(char s[], int lim) {
+	/* Put as much as possible into a temp string, and count its length */
+	int c, i;
+
+	for (i = 0; i < lim && (c = getchar()) != EOF && c != '\n'; ++i) {
+		s[i] = c;
+	}
+	if (c == '\n') {
+		s[i] = c;
+		++i;
+	}
+	s[i] = '\0';
+	return i;
+}
+
+/* Find the first blank character, starting from the end of the string. Returns
+ * the position of the blank, or -1 if one wasn't found.
+ */
+int b_find_blank(char s[], int lim) {
+	// Start at the end of the string and go backwards.
+	for (i = lim; i >= 0; i--) {
+		// Simply replace the first blank with a newline.
+		if (s[i] == ' ' || s[i] == '\t') {
+			return i;
+		}
+	}
+	return -1;
+}
+
+int main() {
+	while (j = get_line(data, MAXLEN)) {
+			if (j == 80) {
+				// We know it's a long line now. Let's make sure we're breaking in
+				// the right place
+				k = b_find_blank(data, MAXLEN);
+				//printf("%d\n", k);
+				if (k > -1) {
+					data[k] = '\n';
+					data[MAXLEN] = '\0';
+					printf("%s", data);
+					continue;
+				} else {
+					data[MAXLEN] = '\0';
+					printf("%s\n", data);
+					continue;
+				}
+			}
+		printf("%s", data);
+	}
+
+}
-- 
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