/* twordcount3.c - threaded word counter for two files.	 *		 - Version 3: one counter per file */#include  <stdio.h>#include  <pthread.h>#include  <ctype.h>struct arg_set {		/* two values in one arg */		char *fname;	/* file to examine	 */		int  count;	/* number of words	 */};main(int ac, char *av[]){	pthread_t      t1, t2;		/* two threads */	struct arg_set args1, args2;	/* two argsets */	void	       *count_words(void *);	if ( ac != 3 ){		printf("usage: %s file1 file2\n", av[0]);		exit(1);	}	args1.fname = av[1];	args1.count = 0;	pthread_create(&t1, NULL, count_words, (void *) &args1);	args2.fname = av[2];	args2.count = 0;	pthread_create(&t2, NULL, count_words, (void *) &args2);	pthread_join(t1, NULL);	pthread_join(t2, NULL);	printf("%5d: %s\n", args1.count, av[1]);	printf("%5d: %s\n", args2.count, av[2]);	printf("%5d: total words\n", args1.count+args2.count);}void *count_words(void *a){	struct arg_set *args = a;	/* cast arg back to correct type */	FILE *fp;	int  c, prevc = '\0';		if ( (fp = fopen(args->fname, "r")) != NULL ){		while( ( c = getc(fp)) != EOF ){			if ( !isalnum(c) && isalnum(prevc) )				args->count++;			prevc = c;		}		fclose(fp);	} else 		perror(args->fname);	return NULL;}