From 5018e06c580dd21c958ec1672c26a3448faf0c55 Mon Sep 17 00:00:00 2001 From: zlg Date: Wed, 13 Feb 2013 20:48:44 -0600 Subject: Add license file, reorganize project --- ch1/1-20_detab.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 ch1/1-20_detab.c (limited to 'ch1/1-20_detab.c') diff --git a/ch1/1-20_detab.c b/ch1/1-20_detab.c new file mode 100644 index 0000000..dc8f5b5 --- /dev/null +++ b/ch1/1-20_detab.c @@ -0,0 +1,48 @@ +#include + +/* The C Programming Language: 2nd Edition + * Exercise 1-20: + * "Write a program `detab` that replaces tabs in the input with the proper + * number of blanks to space to the next tabstop. Assume a fixed set of + * tabstops, say every 'n' columns. Should 'n' be a variable or a symbolic + * parameter?" + * + * Answer: 'n' should be a symbolic parameter. It's more apparent what's being + * worked with and it's not susceptible to scope. Though, in this simple + * program it really doesn't matter. + * + * The "correct" solution uses the isprint() stdlib function, but it's not + * covered by this point in the book, so I did not use it. + */ + +#define TABWIDTH 8 + +int main(void) { + int column, c; + column = 0; + while ((c = getchar()) != EOF) { + // Be sure that the character is a tab + if (c == '\t') { + /* + * Divide a line by TABWIDTH and you have your tabstops. If you + * modulo by TABWIDTH and it equals 0, you've reached a tabstop and + * don't need to output more spaces! + */ + while (column % TABWIDTH != 0 && column != 0) { + putchar(' '); + ++column; + } + } else { + if (c == '\n') { + // Line-endings should reset the column counter after being output. + putchar(c); + column = 0; + } else { + // Now we can just output and increase column! + putchar(c); + ++column; + } + } + } + return 0; +} -- cgit v1.2.3-54-g00ecf