/****************************************************************/
/*	Count the characters, words and lines in a file.	*/
/*								*/
/*	By David Megginson, 1991				*/
/*	Released into the public domain.			*/
/*								*/
/*	Command line options:					*/
/*		-c	Count characters			*/
/*		-w	Count words				*/
/*		-l	Count lines				*/
/*	(count everything by default)				*/
/*								*/
/*	Makefile options:					*/
/*		-DBUFFER_SIZE=n		Read n bytes at a time	*/
/*		-DSKIP_CR		Ignore carriage returns	*/
/****************************************************************/


/* $Id: wc.c,v 1.2 1991/03/05 09:02:30 david Exp david $ */

/*
 * $Log: wc.c,v $
 * Revision 1.2  1991/03/05  09:02:30  david
 * Changed `static version' to `static char * version' (duh!)
 *
 * Revision 1.1  1991/03/05  08:59:46  david
 * Initial revision
 *
 */

static char * version = "$Id: wc.c,v 1.2 1991/03/05 09:02:30 david Exp david $";


#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>

/* The string of legal options for getopt			*/

#define	OPTSTRING	"clw"

/* The size of the read() buffer. Allow the user to define	*/
/* this in the Makefile if desired.				*/

#ifndef	BUFFER_SIZE
#define	BUFFER_SIZE	50000L
#endif

/* Use this buffer to read in the file				*/

static char buffer[BUFFER_SIZE];

/* Number of files read so far, and running totals		*/

static int total_files = 0;
static long total_characters = 0;
static long total_words = 0;
static long total_lines = 0;

/* Flags controlled by command-line options			*/

static int all_flag = 1;	/* count everything (default)	*/
static int c_flag = 0;		/* count characters		*/
static int w_flag = 0;		/* count words			*/
static int l_flag = 0;		/* count lines			*/
static int whitespace_flag = 1;	/* whitespace seen		*/
static int nl_flag = 0;		/* newline seen			*/

/* getopt() stuff						*/

extern int optind;

/* Local functions					*/

static void do_file( const char * filename,int fd );
static void count_buffer( long * c,long * w,long * l,fpos_t length );
static void show_results( long c,long w,long l,const char * filename );
static void show_totals( void );


main( int ac,const char ** av )
{
	int opt,current,fd;

	opt = getopt(ac,av,OPTSTRING);
	while( opt != EOF ) {
		switch( opt ) {

		case 'c':
			all_flag = 0;
			c_flag = 1;
			break;
		case 'l':
			all_flag = 0;
			l_flag = 1;
			break;
		case 'w':
			all_flag = 0;
			w_flag = 1;
			break;
		}
		opt = getopt(ac,av,OPTSTRING);
	}

	if( optind == ac ) {
		do_file(NULL,0);
	} else for( current = optind; current < ac; current++ ) {
		if( !strcmp(av[current],"-") )
			do_file(av[current],0);
		else {
			fd = open(av[current],O_RDONLY);
			if( fd < 0 ) {
				perror(av[current]);
				exit(1);
			}
			do_file(av[current],fd);
			close(fd);
		}
	}

	if( total_files > 1 )
		show_totals();
	return 0;
}

	
/*******
	Count the words in a single file.

	Arguments:	const char * filename	the file name
			int fd			the file descriptor
	Return value:	none
*******/

static void
do_file( const char * filename,int fd )
{
	fpos_t total_read;
	long c=0, w=0, l=0;

	whitespace_flag = 1;
	total_files++;
	
	do {
		total_read = read(fd,buffer,BUFFER_SIZE);
#if DEBUG
printf("Read %ld characters from %s\n",total_read,filename?filename:"stdin");
#endif
		if( total_read > 0 )
			count_buffer(&c,&w,&l,total_read);
	} while( total_read == BUFFER_SIZE );

	/* if the file ended on a word, count that word too	*/
	
	if( !whitespace_flag )
		w++;

	/* if the last character was not NL, count the last	*/
	/* line							*/

	if( !nl_flag )
		l++;
		
	show_results(c,w,l,filename);

	total_characters += c;
	total_words += w;
	total_lines += l;
}


/*******
	Count the buffer itself.

	Arguments:	long * c	characters
			long * w	words
			long * l	lines
			fpos_t length	characters in buffer
	Return value:	none
*******/

void
count_buffer( long * c,long * w,long * l,fpos_t length )
{
	fpos_t pos;

	for( pos = 0; pos < length; pos++ ) {

		switch( buffer[pos] ) {
#ifdef SKIP_CR
		case '\r':
			break;
#endif
		case '\n':
			(*l)++;
			if( !whitespace_flag )
				(*w)++;
			whitespace_flag = 1;
			nl_flag = 1;
			break;
		case ' ':
		case '\t':
			if( !whitespace_flag )
				(*w)++;
			whitespace_flag = 1;
			break;
		default:
			whitespace_flag = 0;
			break;
		}

		/* Always count a character		*/

		(*c)++;
	}
}
			
		
/*******
	Show the results for a file.

	Arguments:	long c		characters
			long w		words
			long l		lines
			const char * filename
	Return value:	none
*******/

void
show_results( long c,long w,long l,const char * filename )
{
	if( all_flag || l_flag )
		printf("%10ld",l);
	if( all_flag || w_flag )
		printf("%10ld",w);
	if( all_flag || c_flag )
		printf("%10ld",c);
	if( filename )
		printf(" %s",filename);
	printf("\n");
}

/*******
	Show the final total for more than one file.

	Arguments:	none
	Return value:	none
*******/

void
show_totals()
{
	if( all_flag || l_flag )
		printf("%10ld",total_lines);
	if( all_flag || w_flag )
		printf("%10ld",total_words);
	if( all_flag || c_flag )
		printf("%10ld",total_characters);
	printf(" TOTAL\n");
}