/*
 * program to print a file with file name and line number
 * prefixing each line
 * invocation:
 *	num		print stdin with line numbers
 *	num arg1 ...	print contents of arg1 with line numbers
 * exit code: number of files not opened
 * author: Matt Bishop, bishop@cs.ucdavis.edu, 9/16/96
 */
#include <stdio.h>
#include <stdlib.h>

/*
 * print the given file, with the file name and line
 * number in front
 * arguments: fn	pointer to file name
 *	      fp	file pointer
 */
void cat(char *fn, FILE *fp)
{
	register int c;			/* input character */
	register int lno = 0;		/* line number */
	register int nlstate = 1;	/* 1 if last char was newline */

	/*
	 * read the file
	 */
	while((c = getc(fp)) != EOF){
		/* was the previous char a newline */
		if (nlstate){
			/* one more line */
			lno++;
			/* print the line number and file name */
			if (fn == NULL) printf("%4d: ", lno);
			else		printf("%s,%4d: ", fn, lno);
			/* we now clear the record of the newline */
			nlstate = 0;
		}
		/* print the character */
		putchar(c);
		/* if it's a newline, set the flag */
		if (c == '\n')
			nlstate = 1;
	}
}

/*
 * the main routine
 */
int main(int argc, char *argv[])
{
	register int nerr = 0;	/* nuber of files not opened */
	register char **a;	/* used to walk argument list */
	register FILE *fp;	/* pointer to file being processed */

	/* 
	 * no argument -- use stdin
	 */
	if (argc == 1){
		cat(NULL, stdin);
		return(EXIT_SUCCESS);
	}

	/*
	 * walk the arg list, doing each file
	 */
	for(a = &argv[1]; *a != NULL; a++)
		/* open the file */
		if ((fp = fopen(*a, "r")) == NULL){
			/* oops ... say what happened */
			perror(*a);
			nerr++;
		}
		else{
			/* print the file */
			cat(*a, fp);
		}
	
	/*
	 * status is the number of files not opened
	 */
	return(nerr);
}