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freebsd/contrib/file/file.c
David E. O'Brien 8ed12636aa Virgin import of Christos Zoulas's FILE 3.39.
2002-09-16 05:54:26 +00:00

560 lines
12 KiB
C
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/*
* 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.
*/
#include "file.h"
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/param.h> /* for MAXPATHLEN */
#include <fcntl.h> /* for open() */
#ifdef RESTORE_TIME
# if (__COHERENT__ >= 0x420)
# include <sys/utime.h>
# else
# ifdef USE_UTIMES
# include <sys/time.h>
# else
# include <utime.h>
# endif
# endif
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h> /* for read() */
#endif
#ifdef HAVE_LOCALE_H
#include <locale.h>
#endif
#ifdef HAVE_GETOPT_H
#include <getopt.h> /* for long options (is this portable?)*/
#endif
#include <netinet/in.h> /* for byte swapping */
#include "patchlevel.h"
#ifndef lint
FILE_RCSID("@(#)$Id: file.c,v 1.66 2002/07/03 19:00:41 christos Exp $")
#endif /* lint */
#ifdef S_IFLNK
# define USAGE "Usage: %s [-bciknsvzL] [-f namefile] [-m magicfiles] file...\n"
#else
# define USAGE "Usage: %s [-bciknsvz] [-f namefile] [-m magicfiles] file...\n"
#endif
#ifdef __EMX__
static char *apptypeName = NULL;
int os2_apptype (const char *fn, char *buf, int nb);
#endif /* __EMX__ */
#ifndef MAGIC
# define MAGIC "/etc/magic"
#endif
#ifndef MAXPATHLEN
#define MAXPATHLEN 512
#endif
int /* Global command-line options */
debug = 0, /* debugging */
lflag = 0, /* follow Symlinks (BSD only) */
bflag = 0, /* brief output format */
zflag = 0, /* follow (uncompress) compressed files */
sflag = 0, /* read block special files */
iflag = 0,
nobuffer = 0, /* Do not buffer stdout */
kflag = 0; /* Keep going after the first match */
int /* Misc globals */
nmagic = 0; /* number of valid magic[]s */
struct magic *magic; /* array of magic entries */
const char *magicfile = 0; /* where the magic is */
const char *default_magicfile = MAGIC;
char *progname; /* used throughout */
int lineno; /* line number in the magic file */
static void unwrap(char *fn);
static void usage(void);
#ifdef HAVE_GETOPT_H
static void help(void);
#endif
#if 0
static int byteconv4(int, int, int);
static short byteconv2(int, int, int);
#endif
int main(int, char *[]);
/*
* main - parse arguments and handle options
*/
int
main(int argc, char **argv)
{
int c;
int action = 0, didsomefiles = 0, errflg = 0, ret = 0, app = 0;
char *mime, *home, *usermagic;
struct stat sb;
#define OPTSTRING "bcdf:ikm:nsvzCL"
#ifdef HAVE_GETOPT_H
int longindex;
static struct option long_options[] =
{
{"version", 0, 0, 'v'},
{"help", 0, 0, 0},
{"brief", 0, 0, 'b'},
{"checking-printout", 0, 0, 'c'},
{"debug", 0, 0, 'd'},
{"files-from", 1, 0, 'f'},
{"mime", 0, 0, 'i'},
{"keep-going", 0, 0, 'k'},
#ifdef S_IFLNK
{"dereference", 0, 0, 'L'},
#endif
{"magic-file", 1, 0, 'm'},
{"uncompress", 0, 0, 'z'},
{"no-buffer", 0, 0, 'n'},
{"special-files", 0, 0, 's'},
{"compile", 0, 0, 'C'},
{0, 0, 0, 0},
};
#endif
#ifdef LC_CTYPE
setlocale(LC_CTYPE, ""); /* makes islower etc work for other langs */
#endif
#ifdef __EMX__
/* sh-like wildcard expansion! Shouldn't hurt at least ... */
_wildcard(&argc, &argv);
#endif
if ((progname = strrchr(argv[0], '/')) != NULL)
progname++;
else
progname = argv[0];
magicfile = default_magicfile;
if ((usermagic = getenv("MAGIC")) != NULL)
magicfile = usermagic;
else
if ((home = getenv("HOME")) != NULL) {
if ((usermagic = malloc(strlen(home) + 8)) != NULL) {
(void)strcpy(usermagic, home);
(void)strcat(usermagic, "/.magic");
if (stat(usermagic, &sb)<0)
free(usermagic);
else
magicfile = usermagic;
}
}
#ifndef HAVE_GETOPT_H
while ((c = getopt(argc, argv, OPTSTRING)) != -1)
#else
while ((c = getopt_long(argc, argv, OPTSTRING, long_options,
&longindex)) != -1)
#endif
switch (c) {
#ifdef HAVE_GETOPT_H
case 0 :
if (longindex == 1)
help();
break;
#endif
case 'b':
++bflag;
break;
case 'c':
action = CHECK;
break;
case 'C':
action = COMPILE;
break;
case 'd':
++debug;
break;
case 'f':
if (!app) {
ret = apprentice(magicfile, action);
if (action)
exit(ret);
app = 1;
}
unwrap(optarg);
++didsomefiles;
break;
case 'i':
iflag++;
if ((mime = malloc(strlen(magicfile) + 6)) != NULL) {
(void)strcpy(mime, magicfile);
(void)strcat(mime, ".mime");
magicfile = mime;
}
break;
case 'k':
kflag = 1;
break;
case 'm':
magicfile = optarg;
break;
case 'n':
++nobuffer;
break;
case 's':
sflag++;
break;
case 'v':
(void) fprintf(stdout, "%s-%d.%d\n", progname,
FILE_VERSION_MAJOR, patchlevel);
(void) fprintf(stdout, "magic file from %s\n",
magicfile);
return 1;
case 'z':
zflag++;
break;
#ifdef S_IFLNK
case 'L':
++lflag;
break;
#endif
case '?':
default:
errflg++;
break;
}
if (errflg) {
usage();
}
if (!app) {
ret = apprentice(magicfile, action);
if (action)
exit(ret);
app = 1;
}
if (optind == argc) {
if (!didsomefiles) {
usage();
}
}
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 void
unwrap(char *fn)
{
char buf[MAXPATHLEN];
FILE *f;
int wid = 0, cwid;
if (strcmp("-", fn) == 0) {
f = stdin;
wid = 1;
} else {
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);
if(nobuffer)
(void) fflush(stdout);
}
(void) fclose(f);
}
#if 0
/*
* byteconv4
* Input:
* from 4 byte quantity to convert
* same whether to perform byte swapping
* big_endian whether we are a big endian host
*/
static int
byteconv4(int from, int same, int big_endian)
{
if (same)
return from;
else if (big_endian) { /* lsb -> msb conversion on msb */
union {
int i;
char c[4];
} retval, tmpval;
tmpval.i = from;
retval.c[0] = tmpval.c[3];
retval.c[1] = tmpval.c[2];
retval.c[2] = tmpval.c[1];
retval.c[3] = tmpval.c[0];
return retval.i;
}
else
return ntohl(from); /* msb -> lsb conversion on lsb */
}
/*
* byteconv2
* Same as byteconv4, but for shorts
*/
static short
byteconv2(int from, int same, int big_endian)
{
if (same)
return from;
else if (big_endian) { /* lsb -> msb conversion on msb */
union {
short s;
char c[2];
} retval, tmpval;
tmpval.s = (short) from;
retval.c[0] = tmpval.c[1];
retval.c[1] = tmpval.c[0];
return retval.s;
}
else
return ntohs(from); /* msb -> lsb conversion on lsb */
}
#endif
/*
* process - process input file
*/
void
process(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 stat sb;
int nbytes = 0; /* number of bytes read from a datafile */
char match = '\0';
if (strcmp("-", inname) == 0) {
if (fstat(0, &sb)<0) {
error("cannot fstat `%s' (%s).\n", stdname,
strerror(errno));
/*NOTREACHED*/
}
inname = stdname;
}
if (wid > 0 && !bflag)
(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(iflag ? "application/x-empty" : "empty", stdout);
else {
buf[nbytes++] = '\0'; /* null-terminate it */
match = tryit(inname, buf, nbytes, zflag);
}
#ifdef BUILTIN_ELF
if (match == 's' && nbytes > 5) {
/*
* We matched something in the file, so this *might*
* be an ELF file, and the file is at least 5 bytes long,
* so if it's an ELF file it has at least one byte
* past the ELF magic number - try extracting information
* from the ELF headers that can't easily be extracted
* with rules in the magic file.
*/
tryelf(fd, buf, nbytes);
}
#endif
if (inname != stdname) {
#ifdef RESTORE_TIME
/*
* Try to restore access, modification times if read it.
* This is really *bad* because it will modify the status
* time of the file... And of course this will affect
* backup programs
*/
# ifdef USE_UTIMES
struct timeval utsbuf[2];
utsbuf[0].tv_sec = sb.st_atime;
utsbuf[1].tv_sec = sb.st_mtime;
(void) utimes(inname, utsbuf); /* don't care if loses */
# else
struct utimbuf utbuf;
utbuf.actime = sb.st_atime;
utbuf.modtime = sb.st_mtime;
(void) utime(inname, &utbuf); /* don't care if loses */
# endif
#endif
(void) close(fd);
}
(void) putchar('\n');
}
int
tryit(const char *fn, unsigned char *buf, int nb, int zfl)
{
/*
* The main work is done here!
* We have the file name and/or the data buffer to be identified.
*/
#ifdef __EMX__
/*
* Ok, here's the right place to add a call to some os-specific
* routine, e.g.
*/
if (os2_apptype(fn, buf, nb) == 1)
return 'o';
#endif
/* try compression stuff */
if (zfl && zmagic(fn, buf, nb))
return 'z';
/* try tests in /etc/magic (or surrogate magic file) */
if (softmagic(buf, nb))
return 's';
/* try known keywords, check whether it is ASCII */
if (ascmagic(buf, nb))
return 'a';
/* abandon hope, all ye who remain here */
ckfputs(iflag ? "application/octet-stream" : "data", stdout);
return '\0';
}
static void
usage(void)
{
(void)fprintf(stderr, USAGE, progname);
(void)fprintf(stderr, "Usage: %s -C [-m magic]\n", progname);
#ifdef HAVE_GETOPT_H
(void)fputs("Try `file --help' for more information.\n", stderr);
#endif
exit(1);
}
#ifdef HAVE_GETOPT_H
static void
help(void)
{
puts(
"Usage: file [OPTION]... [FILE]...\n"
"Determine file type of FILEs.\n"
"\n"
" -m, --magic-file LIST use LIST as a colon-separated list of magic\n"
" number files\n"
" -z, --uncompress try to look inside compressed files\n"
" -b, --brief do not prepend filenames to output lines\n"
" -c, --checking-printout print the parsed form of the magic file, use in\n"
" conjunction with -m to debug a new magic file\n"
" before installing it\n"
" -f, --files-from FILE read the filenames to be examined from FILE\n"
" -i, --mime output mime type strings\n"
" -k, --keep-going don't stop at the first match\n"
" -L, --dereference causes symlinks to be followed\n"
" -n, --no-buffer do not buffer output\n"
" -s, --special-files treat special (block/char devices) files as\n"
" ordinary ones\n"
" --help display this help and exit\n"
" --version output version information and exit\n"
);
exit(0);
}
#endif
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