CSC161 2010F, Class 07: Basic Input and Output in C

Overview:
* I/O Basics.
* A Group Exercise.
* Lab!

Admin:
* Notes on Web site
* Are there questions on assignment 2?
  * Is #13 really as much of a beast as it seems to be?
    * Identify when you've hit the end of a word.  (Steal from book.
    Cite.)
    * Keep track of how many characters are in a word.  (May be in
      the book.  Otherwise: Counter variable.  Set to 1 when you
      begin a word.  Increment at each character.)
    * Keep the histogram: An array of size 10 or 11, depending on what
      you find easier.  Alternately: 10 variables.
    * Print the histogram in rows: For loop
* Note that the due date was changed until Thurday.
* I had a request to go a bit slower on how you compile, and I will do so.
* I expect to grade assignment 1 tonight.
* For tomorrow: Read K&R 5.10 (The Command Line)

Input and output in C
* Taken from the library <stdio.h>
* printf for writing stuff
  printf (FORMATTING INSTRUCTIONS, stuff, more stuff, even more stuff)
  * Each bit of stuff gets plugged in in order.
  * A percent sign indicates that you want to plug in something
  * The stuff after the percent sign indicates the type and other
    issues.
  printf ("Your grade is %d.", yourgrade);
  printf ("Your grade is %3d.", yourgrade);
  printf ("Your grade is %03d.", yourgrade);

* scanf for reading stuff
  scanf (FORMAT INSTRUCTIONS, stuff, more stuff, even more stuff);
  * Each bit of stuff gets filled in in order.
  * A percent sign indicates that you want to fill in something
  * The stuff after the percent sign indicates the kind of thing you want
    to read.
  * Precede each variable by an ampersand (for reasons we'll cover later).
  scanf ("%d", &grade);
  scanf ("%1d", &grade);
  scanf ("%1d%1d%1d", &a, &b, &c);

* putchar to write individual characters/bytes
* getchar to read individual characters/bytes
* How would you find out more about printf
  man 3 printf
  Look in the dead tree volume which is carefully hidden under a pile
  of papers in Sam's office (or maybe lab)