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authorzlg <zlg@zlg.space>2013-01-09 01:10:15 -0600
committerzlg <zlg@zlg.space>2013-01-09 01:10:15 -0600
commit1f7068ac3281c0651c876d99612432a36c298f90 (patch)
tree34f1f5347390ccc04a052470c27909d50687e707
parentClean up 1-13 and 1-20, correct 1-21 (diff)
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Solve Exercise 1-22: wordwrap
* Removed unnecessary get_line() function in 1-17 * Corrected grammar in README, added an acknowledgement
Diffstat (limited to '')
-rw-r--r--1-17_over-80.c15
-rw-r--r--1-22_wordwrap.c75
-rw-r--r--README.mdown13
3 files changed, 82 insertions, 21 deletions
diff --git a/1-17_over-80.c b/1-17_over-80.c
index dcf7058..53f00ce 100644
--- a/1-17_over-80.c
+++ b/1-17_over-80.c
@@ -2,21 +2,6 @@
#define MINLENGTH 80
-/* Read as much as possible of a string and return its length. */
-int get_line(char s[]) {
- int c, i;
-
- for (i = 0; i < MINLENGTH - 1 && (c = getchar()) != EOF; ++i) {
- s[i] = c;
- }
- if (c == '\n') {
- s[i] = c;
- ++i;
- }
- s[i] = '\0';
- return i;
-}
-
int main() {
// longline is used as a boolean that tells us if it's a line worth printing
int longline = 0;
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);
+ }
+
+}
diff --git a/README.mdown b/README.mdown
index 1fafb61..f5d961a 100644
--- a/README.mdown
+++ b/README.mdown
@@ -1,8 +1,8 @@
-These files are my solutions to Kernighan and Ritchie's *The C Programming
-Language, 2nd Edition*. My aim is to deepen my understanding of C, using only
-the concepts covered in content that comes before each exercise. That means no
-"cheating" by using standard library features that aren't been covered in the
-book yet. As a result, many of my solutions will probably not be "the best", but
+These files are my solutions to Kernighan and Ritchie's *The C Programming
+Language, 2nd Edition*. My aim is to deepen my understanding of C, using only
+the concepts covered in content that comes before each exercise. That means no
+"cheating" by using standard library features that aren't covered in the book
+yet. As a result, many of my solutions will probably not be "the best", but
suitable for the goal at hand: *learning*.
I chose this route because as I was reading the K&R, I didn't feel like I was
@@ -12,4 +12,5 @@ why was I learning C? I tackled a few exercises and found that I was beginning
to learn a few things I hadn't ran into before.
Critique is welcome, but please keep in mind the limitations I've outlined in
-the first paragraph.
+the first paragraph. Also note that some incomplete implementations are noted,
+which I intend on revisiting. Any suggestions and advice are welcome.