/* * 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 #include #include #include /* for MAXPATHLEN */ #include /* for open() */ #ifdef RESTORE_TIME # if (__COHERENT__ >= 0x420) # include # else # ifdef USE_UTIMES # include # else # include # endif # endif #endif #ifdef HAVE_UNISTD_H #include /* for read() */ #endif #ifdef HAVE_LOCALE_H #include #endif #ifdef HAVE_GETOPT_H #include /* for long options (is this portable?)*/ #endif #include /* for byte swapping */ #include "patchlevel.h" #ifndef lint FILE_RCSID("@(#)$Id: file.c,v 1.69 2003/02/27 20:47:46 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, nopad = 0, /* Don't pad output */ 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 separator = ':'; /* Default field separator */ char *progname; /* used throughout */ int lineno; /* line number in the magic file */ static void unwrap(char *fn); static void usage(void); #ifdef HAVE_GETOPT_LONG 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:F:ikm:nNsvzCL" #ifdef HAVE_GETOPT_LONG 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'}, {"separator", 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'}, {"no-pad", 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_LONG 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_LONG 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 'F': separator = *optarg; 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 'N': ++nopad; 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%c%*s", inname, separator, (int) (nopad ? 0 : 1 + (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("writable, ", 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_LONG (void)fputs("Try `file --help' for more information.\n", stderr); #endif exit(1); } #ifdef HAVE_GETOPT_LONG 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