filetype.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static char *sccsid = "@(#)filetype.c	4.1      ULTRIX 	10/16/90";
#endif

/************************************************************************
 *									*
 *			Copyright (c) 1990 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/
/*
 * Modification History: reverse order
 *
 * 26-Sep-1990 - Adrian Thoms (thoms@wessex)
 *	Carved out all the magic number code into a separate file
 *	so that it could be used as a guesser library module for the
 *	print system.
 */

/************************************************************************
 *			Modification History				*
 * 001 Richard Hart, Oct. 21, 1987					*
 *     Copied from 4.3 BSD code:					*
 *		file.c 4.12	(Berkeley) 11/17/85			*
 * 002 Richard Hart, Oct. 21, 1987					*
 *     Added named pipes for Sys V support, and other things in the	*
 *     current Ultrix file.c						*
 * 003 Richard Hart, Oct. 22, 1987					*
 *     Added use of /etc/magic, like Sys V filecommand			*
 * 004 Richard Hart, Nov. 5, 1987					*
 *     Now uses sys/exec.h for support of a.out magic numbers		*
 * 005 Ricky Palmer, Aug. 5, 1988					*
 *     Ifdef'ed for vax/mips.						*
 * 006 Jon Reeves, Nov 12, 1988						*
 *     Fixed ifdefs to allow mode code to work.				*
 * 007 Tim Burke, June 12, 1989						*
 *     Added check for the tape density of DEV_38000BPI which is used   *
 *     on the TA90 tape drive.  Print out "loader" if the tape has a	*
 *     media loader.							*
 * 008 Tim Burke, Sep 13, 1989						*
 *	Added the following TA90 densities: DEV_38000_CP, DEV_76000BPI  *
 *	and DEV_76000_CP.						*
 * 009 Bill Dallas, Jul 05,1990						*
 *	Added the following QIC densities DEV_8000_BPI, DEV_10000_BPI	*
 *	and DEV_16000_BPI.
 *									*
 ************************************************************************/

/*
 * filetype - determine type of file
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <sys/devio.h>
#include <stdio.h>
#include <ctype.h>
#include "filetype.h"
#include "magic_data.h"

/*
**	Misc
*/

#define	NENT	200
#define	BSZ	128
#define	FBSZ	512

extern char	*mfile;
extern char	*sys_errlist[];

struct devget devget;
int	errno;
int	sys_nerr;
static int in;



char *troff[] = {	/* new troff intermediate lang */
	"x","T","res","init","font","202","V0","p1",0};
char *fort[] = {
	"function","subroutine","common","dimension","block","integer",
	"real","data","double",0};
char *asc[] = {
	"chmk","mov","tst","clr","jmp",0};
char *cstart[] = {
	"#include", "#ifndef", "static", "stdio.h", 0};
char *c[] = {
	"int","char","float","double","struct","extern","include",0};
char *as[] = {
	"globl","byte","align","text","data","comm",0};
char *sh[] = {
	"fi", "elif", "esac", "done", "export",
	"readonly", "trap", "PATH", "HOME", 0 };
char *csh[] = {
	"alias", "breaksw", "endsw", "foreach", "limit",  "onintr",
	"repeat", "setenv", "source", "path", "home", 0 };

int i  = 0;
extern int	ifile;
char buf[BUFSIZ];

long
filetype(file, pflg)
char *file;
int pflg;
{
	int j,nl;
	char ch;
	int minornum, majornum;
	long retnum;
	struct stat mbuf;
	char slink[MAXPATHLEN + 1];
	struct devget *pdevget = &devget;

	if (ifile >= 0)
		close(ifile);		/* close any file that was opened on a previous call */
	ifile = -1;
	if (lstat(file, &mbuf) < 0) {
		if (pflg) printf("%s\n",
		    (unsigned)errno < sys_nerr? sys_errlist[errno]: "Cannot stat");
		return(MASH(UNKNOWN, UNKNOWN));
	}

	switch (mbuf.st_mode & S_IFMT) {

	case S_IFLNK:
		if (pflg) printf("symbolic link");
		j = readlink(file, slink, sizeof slink - 1);
		if (j >= 0) {
			slink[j] = '\0';
			if (pflg) printf(" to %s", slink);
		}
		if (pflg) printf("\n");
		return(MASH(SLINK, UNKNOWN));

	case S_IFDIR:
		minornum = STANDARD;
		if (mbuf.st_mode & S_ISVTX)
			if (pflg) printf("append-only ");
			minornum = APPENDONLY;
		if (pflg) printf("directory\n");
		return(MASH(DIRECTORY, minornum));

	case S_IFPORT: 
		if (pflg) printf("port (named pipe\n");
		return(MASH(NAMEDPIPE, UNKNOWN));

	case S_IFSOCK:
		if (pflg) printf("socket\n");
		return(MASH(SOCKET, UNKNOWN));

	case S_IFBLK:
		if (pflg) printf("block special (%d/%d)\n", major(mbuf.st_rdev), minor(mbuf.st_rdev));
		return(MASH(SPECIAL, BLOCK));

	case S_IFCHR:
		if (!pflg)
			return(MASH(SPECIAL, CHARACTER));
		printf("character special (%d/%d)", major(mbuf.st_rdev), minor(mbuf.st_rdev));
                ifile = open(file, (O_RDONLY|O_NDELAY));
                if(ifile < 0)
                        ifile = open(file, (O_WRONLY|O_NDELAY));
                if(ifile < 0) {
                    printf("\n");
                    return;
                }
                if(ioctl(ifile,DEVIOCGET,(char *) pdevget) < 0) {
                    printf("\n");
                } else {
                    if((strcmp(DEV_UNKNOWN,pdevget->interface) == 0) ||
                       (pdevget->ctlr_num == -1)) {
                            printf(" ");
                    } else {
                            printf(" %s #%d ", pdevget->interface,
                                   pdevget->ctlr_num);
                    }
                    if(!(strcmp(DEV_UNKNOWN,pdevget->device) == 0)) {
                            printf("%s ", pdevget->device);
                    }
                    switch(pdevget->category) {
                    case DEV_TAPE:
                            printf("tape ");
                            break;
                    case DEV_DISK:
                            printf("disk ");
                            break;
                    case DEV_TERMINAL:
                            printf("terminal ");
                            break;
                    case DEV_PRINTER:
                            printf("printer ");
                            break;
                    case DEV_SPECIAL:
                            printf("special_device ");
                            break;
                    default:
                            printf("unknown ");
                            break;
                    }
                    if(!(pdevget->slave_num == -1)) {
                            printf("#%d ", pdevget->slave_num);
                    }
                    if(pdevget->soft_count || pdevget->hard_count) {
                        printf("errors = %d/%d ", pdevget->soft_count,
                           pdevget->hard_count);
                    }
                    if(pdevget->stat & DEV_OFFLINE) {
                        printf("offline ");
                    } else if(pdevget->stat & DEV_WRTLCK) {
                        printf("write-locked ");
                    }
                    if((pdevget->category == DEV_TAPE) &&
                       !(pdevget->stat & DEV_OFFLINE)) {            
                        if(pdevget->category_stat & DEV_LOADER) {
                                printf("loader ");
			}
                        if(pdevget->category_stat & DEV_800BPI) {
                                printf("800_bpi\n");
                        } else if(pdevget->category_stat & DEV_1600BPI) {
                                printf("1600_bpi\n");
                        } else if(pdevget->category_stat & DEV_6250BPI) {
                                printf("6250_bpi\n");
                        } else if(pdevget->category_stat & DEV_6666BPI) {
                                printf("6666_bpi\n");
                        } else if(pdevget->category_stat & DEV_8000_BPI) {
                                printf("8000_bpi\n");
                        } else if(pdevget->category_stat & DEV_10000_BPI) {
                                printf("10000_bpi\n");
                        } else if(pdevget->category_stat & DEV_10240BPI) {
                                printf("10240_bpi\n");
                        } else if(pdevget->category_stat & DEV_16000_BPI) {
                                printf("16000_bpi\n");
                        } else if(pdevget->category_stat & DEV_38000BPI) {
                                printf("38000_bpi\n");
                        } else if(pdevget->category_stat & DEV_38000_CP) {
                                printf("38000_bpi compacted\n");
                        } else if(pdevget->category_stat & DEV_76000BPI) {
                                printf("76000_bpi\n");
                        } else if(pdevget->category_stat & DEV_76000_CP) {
                                printf("76000_bpi compacted\n");
                        } else {
				/*
				 * Density unknown.
				 */
                                printf("unspecified density\n");
                        }
                    } else if(pdevget->category == DEV_TERMINAL) {
                        if(pdevget->category_stat & DEV_MODEM) {
                                printf("modem_control ");
                                if(pdevget->category_stat & DEV_MODEM_ON) {
                                        printf("on\n");
                                } else {
                                        printf("off\n");
                                }
                        } else {
                                printf("\n");
                        }
                    } else {
                        printf("\n");
                    }
                }
        return;
        }

	ifile = open(file, 0);
	if(ifile < 0) {
		if (pflg) printf("%s\n",
			(unsigned)errno < sys_nerr? sys_errlist[errno]: "Cannot read");
		return(MASH(UNKNOWN, UNKNOWN));
	}
	retnum = fdtype(ifile, &mbuf, &in, buf, BUFSIZ, pflg);

	if (retnum) {
		return(retnum);
	}
	if (pflg) printf("Entering grock code\n");
	/* check for various types of ascii text files now using keyword lists */
	if (cprog() == 1) {
		if (pflg) printf("c program text");
		retnum = CPROG;
		 /* 	checkgarbage();  */
		goto outa;
		}
	else if (fortprog() == 1) {
		if (pflg) printf("fortran program text");
		retnum = FORTPROG;
		goto outa;
		}
notfort:
	i=0;
	if(ascom() == 0)goto notas;
	j = i-1;
	if(buf[i] == '.'){
		i++;
		if(lookup(as) == 1){
			if (pflg) printf("assembler program text"); 
			retnum = ASSEMBLER;
			goto outa;
		}
		else if(buf[j] == '\n' && isalpha(buf[j+2])){
			if (pflg) printf("roff, nroff, or eqn input text");
			retnum = NROFF;
			goto outa;
		}
	}
	while(lookup(asc) == 0){
		if(ascom() == 0)goto notas;
		while(buf[i] != '\n' && buf[i++] != ':')
			if(i >= in)goto notas;
		while(buf[i] == '\n' || buf[i] == ' ' || buf[i] == '\t')if(i++ >= in)goto notas;
		j = i-1;
		if(buf[i] == '.'){
			i++;
			if(lookup(as) == 1){
				if (pflg) printf("assembler program text"); 
				retnum = ASSEMBLER;
				goto outa; 
			}
			else if(buf[j] == '\n' && isalpha(buf[j+2])){
				if (pflg) printf("roff, nroff, or eqn input text");
				retnum = NROFF;
				goto outa;
			}
		}
	}
	if (pflg) printf("assembler program text");
	retnum = ASSEMBLER;
	goto outa;
notas:
	if (troffint(buf, in)) {
		if (pflg) printf("troff intermediate output text");
		retnum = TROFFINT;
	}
	else if (shell(buf, in, sh)) {
		if (pflg) printf("%sshell commands", execmodes(&mbuf, buf));
		retnum = SHELL;
	}
	else if (shell(buf, in, csh)) {
		if (pflg) printf("%sc-shell commands", execmodes(&mbuf, buf));
		retnum = CSHELL;
	}
	else if (english(buf, in)) {
		if (pflg) printf("English text");
		retnum = ENGLISH;
	}
	else {
		if (pflg) printf("ASCII text");
		retnum = UNKNOWN;
	}
outa:
	while(i < in)
		if((buf[i++]&0377) > 127){
			if (pflg) printf(" with garbage\n");
			return(MASH(ASCIIwGARBAGE, retnum));
		}
	/* if next few lines in then read whole file looking for nulls ...
		while((in = read(ifile,buf,BUFSIZ)) > 0)
			for(i = 0; i < in; i++)
				if((buf[i]&0377) > 127){
					if (pflg) printf(" with garbage\n");
					return(MASH(ASCIIwGARBAGE, retnum));
				}
		/*.... */
	if (pflg) printf("\n");
	return(MASH(ASCII, retnum));
}

mkmtab(cflg)
reg	int	cflg;
{
	reg	Entry	*ep;
	reg	FILE	*fp;
	reg	int	lcnt = 0;
	auto	char	buf[BSZ];
	auto	Entry	*mend;
	auto majnum, minnum;
	char *strchr();

	ep = (Entry *) calloc(sizeof(Entry), NENT);
	if(ep == NULL) {
		fprintf(stderr, "file: no memory for magic table.\n");
		exit(2);
	}
	mtab = ep;
	mend = &mtab[NENT];
	fp = fopen(mfile, "r");
	if(fp == NULL) {
		fprintf(stderr, "file: cannot open magic file <%s>.\n", mfile);
		exit(2);
	}
	while(fgets(buf, BSZ, fp) != NULL) {
		reg	char	*p = buf;
		reg	char	*p2, *p3;
		reg	char	opc;
		int count;

		if(*p == '\n' || *p == '#')
			continue;