Add exercise descriptions and answers for ch1

* Corrected behavior in solutions for 1-9 and 1-23

1 files changed, 14 insertions, 3 deletions

diff --git a/ch1/1-18_strip-blanks.c b/ch1/1-18_strip-blanks.c
index c766445..947ce8d 100644
--- a/ch1/1-18_strip-blanks.c
+++ b/ch1/1-18_strip-blanks.c
@@ -1,8 +1,16 @@
 #include <stdio.h>
 
+/* The C Programming Language: 2nd Edition
+ *
+ * Exercise 1-18: Write a program to remove trailing blanks and tabs from each
+ * line of input, and to delete entirely blank lines.
+ *
+ * Answer: Simple -- start from the end of the line and look for a non-blank
+ * character. Once found, place your \n and \0 just afterwards. By checking
+ * that 'i' > 1, it ensures that blank lines never get spit out, since a line
+ * with content will always be 2 or more characters long due to the \n.
+ */
 #define MAXLINELENGTH 9001
-/* Write a program to remove trailing blanks and tabs from each line of input,
-   and to delete entirely blank lines. */
 
 int get_line(char s[], int lim) {
 	int c, i;
@@ -24,7 +32,10 @@ int main(void) {
 
 	/* Make sure every line is gone over */
 	while (len = get_line(buffer, MAXLINELENGTH)) {
-		/* An empty for statement, simply to change the i variable. */
+		/* An empty for statement, simply to change the i variable.
+		 * Subtracting 2 from 'len' is to account for 0-based indexing and the \0
+		 * string terminator.
+		 */
 		for (i = len - 2; (i > 0) && (buffer[i] == ' ') || (buffer[i] == '\t'); --i);
 
 		/* We've reached the end of the line's actual content. Terminate the line. */