diff options
Diffstat (limited to 'ch1/1-18_strip-blanks.c')
| -rw-r--r-- | ch1/1-18_strip-blanks.c | 17 |
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. */ |