/* * file - find type of a file or files - main program. * * Copyright (c) Ian F. Darwin, 1987. * Written by Ian F. Darwin. * * This software is not subject to any license of the American Telephone * and Telegraph Company or of the Regents of the University of California. * * Permission is granted to anyone to use this software for any purpose on * any computer system, and to alter it and redistribute it freely, subject * to the following restrictions: * * 1. The author is not responsible for the consequences of use of this *    software, no matter how awful, even if they arise from flaws in it. * * 2. The origin of this software must not be misrepresented, either by *    explicit claim or by omission.  Since few users ever read sources, *    credits must appear in the documentation. * * 3. Altered versions must be plainly marked as such, and must not be *    misrepresented as being the original software.  Since few users *    ever read sources, credits must appear in the documentation. * * 4. This notice may not be removed or altered. */#ifndef	lintstatic char *moduleid = 	"@(#)$Id: file.c,v 1.29 1993/10/27 20:59:05 christos Exp $";#endif	/* lint */#include <stdio.h>#include <stdlib.h>#include <string.h>#include <sys/types.h>#include <sys/param.h>	/* for MAXPATHLEN */#include <sys/stat.h>#include <fcntl.h>	/* for open() */#include <utime.h>#include <unistd.h>	/* for read() */#include "file.h"#ifdef S_IFLNK# define USAGE  "Usage: %s [-czL] [-f namefile] [-m magicfile] file...\n"#else# define USAGE  "Usage: %s [-cz] [-f namefile] [-m magicfile] file...\n"#endif#ifndef MAGIC# define MAGIC "/etc/magic"#endifint 			/* Global command-line options 		*/	debug = 0, 	/* debugging 				*/	lflag = 0,	/* follow Symlinks (BSD only) 		*/	zflag = 0;	/* follow (uncompress) compressed files */int			/* Misc globals				*/	nmagic = 0;	/* number of valid magic[]s 		*/struct  magic *magic;	/* array of magic entries		*/char *magicfile = MAGIC;/* where magic be found 		*/char *progname;		/* used throughout 			*/int lineno;		/* line number in the magic file	*/static void unwrap	__P((char *fn));/* * main - parse arguments and handle options */intmain(argc, argv)int argc;char *argv[];{	int c;	int check = 0, didsomefiles = 0, errflg = 0, ret = 0;	if ((progname = strrchr(argv[0], '/')) != NULL)		progname++;	else		progname = argv[0];	while ((c = getopt(argc, argv, "cdf:Lm:z")) != EOF)		switch (c) {		case 'c':			++check;			break;		case 'd':			++debug;			break;		case 'f':			unwrap(optarg);			++didsomefiles;			break;#ifdef S_IFLNK		case 'L':			++lflag;			break;#endif		case 'm':			magicfile = optarg;			break;		case 'z':			zflag++;			break;		case '?':		default:			errflg++;			break;		}	if (errflg) {		(void) fprintf(stderr, USAGE, progname);		exit(2);	}	ret = apprentice(magicfile, check);	if (check)		exit(ret);	if (optind == argc) {		if (!didsomefiles) {			(void)fprintf(stderr, USAGE, progname);			exit(2);		}	}	else {		int i, wid, nw;		for (wid = 0, i = optind; i < argc; i++) {			nw = strlen(argv[i]);			if (nw > wid)				wid = nw;		}		for (; optind < argc; optind++)			process(argv[optind], wid);	}	return 0;}/* * unwrap -- read a file of filenames, do each one. */static voidunwrap(fn)char *fn;{	char buf[MAXPATHLEN];	FILE *f;	int wid = 0, cwid;	if ((f = fopen(fn, "r")) == NULL) {		error("Cannot open `%s' (%s).\n", fn, strerror(errno));		/*NOTREACHED*/	}	while (fgets(buf, MAXPATHLEN, f) != NULL) {		cwid = strlen(buf) - 1;		if (cwid > wid)			wid = cwid;	}	rewind(f);	while (fgets(buf, MAXPATHLEN, f) != NULL) {		buf[strlen(buf)-1] = '\0';		process(buf, wid);	}	(void) fclose(f);}/* * process - process input file */voidprocess(inname, wid)const char	*inname;int wid;{	int	fd = 0;	static  const char stdname[] = "standard input";	unsigned char	buf[HOWMANY+1];	/* one extra for terminating '\0' */	struct utimbuf  utbuf;	struct stat	sb;	int nbytes = 0;	/* number of bytes read from a datafile */	if (strcmp("-", inname) == 0) {		if (fstat(0, &sb)<0) {			error("cannot fstat `%s' (%s).\n", stdname, 			      strerror(errno));			/*NOTREACHED*/		}		inname = stdname;	}	if (wid > 0)	     (void) printf("%s:%*s ", inname, 			   (int) (wid - strlen(inname)), "");	if (inname != stdname) {	    /*	     * first try judging the file based on its filesystem status	     */	    if (fsmagic(inname, &sb) != 0) {		    putchar('\n');		    return;	    }			    if ((fd = open(inname, O_RDONLY)) < 0) {		    /* We can't open it, but we were able to stat it. */		    if (sb.st_mode & 0002) ckfputs("writeable, ", stdout);		    if (sb.st_mode & 0111) ckfputs("executable, ", stdout);		    ckfprintf(stdout, "can't read `%s' (%s).\n",			inname, strerror(errno));		    return;	    }	}	/*	 * try looking at the first HOWMANY bytes	 */	if ((nbytes = read(fd, (char *)buf, HOWMANY)) == -1) {		error("read failed (%s).\n", strerror(errno));		/*NOTREACHED*/	}	if (nbytes == 0) 		ckfputs("empty", stdout);	else {		buf[nbytes++] = '\0';	/* null-terminate it */		tryit(buf, nbytes, zflag);	}	if (inname != stdname) {		/*		 * Try to restore access, modification times if read it.		 */		utbuf.actime = sb.st_atime;		utbuf.modtime = sb.st_mtime;		(void) utime(inname, &utbuf); /* don't care if loses */		(void) close(fd);	}	(void) putchar('\n');}voidtryit(buf, nb, zflag)unsigned char *buf;int nb, zflag;{	/*	 * Try compression stuff	 */	if (!zflag || zmagic(buf, nb) != 1)		/*		 * try tests in /etc/magic (or surrogate magic file)		 */		if (softmagic(buf, nb) != 1)			/*			 * try known keywords, check for ascii-ness too.			 */			if (ascmagic(buf, nb) != 1)			    /*			     * abandon hope, all ye who remain here			     */			    ckfputs("data", stdout);}