#include <stdio.h>
#include <string.h>

/*
 * This is a plain C version of the C++ string example.  It contains several
 * things which I may not explain fully, and is mostly to show that using
 * strings in plain C is ... special.
 *
 * Plain C strings are fixed length, and this program sets a limit of 100,
 * so the semantics will differ from the C++ one if you enter long string.
 */

int main()
{
	// This declares line as an array of 100 chars, which can
	// store a string of size 0 to 99.  The extra byte is needed
	// for a terminator, which is a zero byte.  Fgets reads a line
	// much as getline, but if the line has more than characters
	// than line can hold, it just stops reading, leaving the
	// remaining characters.  Also, it leaves the \n in the
	// string, which I have to get rid of.  Stdin is the plain C
	// equivalent of cin, but in most cases itis also the default
	// for reading.
	char line[100];
	printf("Please enter a line:\n> ");
	fgets(line, sizeof line, stdin);
	line[strlen(line)-1] = 0;  // This removes the last character.

	// Again, read a word, this time using scanf.  Scanf %s is similar
	// to reading a string with cout >>, in that it skips leading
	// spaces and reads a non-blank string.  Unlike all other types,
	// arrays do not need an & on the variable.
	char word[100];
	printf("Please enter a single word: ");
	scanf("%s", word);

	// Printf uses %s for a string.
	printf("You entered %s and %s\n", word, line);

	// Plain C strings can be compared with the strcmp() utility, which
	// returns negative, zero, or positive much like Java .compareTo().
	if(strcmp(word,"wombat") == 0)
		printf("You entered \"wombat\".  My favorite word!\n");

	// The find operation searches for one string in another, and returns
	// the position, or NULL to indicate not found.  The position is a
	// pointer, which is a pointer, the memory address of the found string.
	char *loc = strstr(line, word);
	if(loc == NULL)
		printf("Your word is not in your line.  Oh well.\n");
	else
		printf("Your word is at %d in your line.\n", loc - line);

	// Plain C strings are arrays of characters, terminated by character 0.
	for(int i = 0; word[i] != 0; ++i) {
		printf("-%c- ", word[i]);
	}
	printf("\n");
}