/* * 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" #ifdef __CYGWIN__ #include #endif #include #include #include #include #include /* for MAXPATHLEN */ #include #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 #include /* for byte swapping */ #include "patchlevel.h" #ifndef lint FILE_RCSID("@(#)$Id: file.c,v 1.47 1999/10/31 22:23:03 christos Exp $") #endif /* lint */ #ifdef S_IFLNK # define USAGE "Usage: %s [-bcnvzL] [-f namefile] [-m magicfiles] file...\n" #else # define USAGE "Usage: %s [-bcnvz] [-f namefile] [-m magicfiles] file...\n" #endif #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 */ nobuffer = 0; /* Do not buffer stdout */ int /* Misc globals */ nmagic = 0; /* number of valid magic[]s */ struct magic *magic; /* array of magic entries */ const char *magicfile; /* where magic be found */ char *progname; /* used throughout */ int lineno; /* line number in the magic file */ static void unwrap __P((char *fn)); #if 0 static int byteconv4 __P((int, int, int)); static short byteconv2 __P((int, int, int)); #endif int main __P((int, char *[])); /* * main - parse arguments and handle options */ int main(argc, argv) int argc; char *argv[]; { int c; int check = 0, didsomefiles = 0, errflg = 0, ret = 0, app = 0; if ((progname = strrchr(argv[0], '/')) != NULL) progname++; else progname = argv[0]; if (!(magicfile = getenv("MAGIC"))) magicfile = MAGIC; while ((c = getopt(argc, argv, "bcdnf:m:svzL")) != EOF) switch (c) { 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 'b': ++bflag; break; case 'c': ++check; break; case 'n': ++nobuffer; break; case 'd': ++debug; break; case 'f': if (!app) { ret = apprentice(magicfile, check); if (check) exit(ret); app = 1; } unwrap(optarg); ++didsomefiles; break; #ifdef S_IFLNK case 'L': ++lflag; break; #endif case 'm': magicfile = optarg; break; case 'z': zflag++; break; case 's': sflag++; break; case '?': default: errflg++; break; } if (errflg) { (void) fprintf(stderr, USAGE, progname); exit(2); } if (!app) { ret = apprentice(magicfile, check); if (check) exit(ret); app = 1; } 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 void unwrap(fn) 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(from, same, big_endian) 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(from, same, big_endian) 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(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 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("empty", stdout); else { buf[nbytes++] = '\0'; /* null-terminate it */ match = tryit(buf, nbytes, zflag); } #ifdef BUILTIN_ELF if (match == 's' && nbytes > 5) 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(buf, nb, zflag) unsigned char *buf; int nb, zflag; { /* try compression stuff */ if (zflag && zmagic(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'; /* see if it's international language text */ if (internatmagic(buf, nb)) return 'i'; /* abandon hope, all ye who remain here */ ckfputs("data", stdout); return '\0'; }