diff options
Diffstat (limited to 'usr.bin/file/file.c')
| -rw-r--r-- | usr.bin/file/file.c | 276 |
1 files changed, 276 insertions, 0 deletions
diff --git a/usr.bin/file/file.c b/usr.bin/file/file.c new file mode 100644 index 0000000..a8acdd4 --- /dev/null +++ b/usr.bin/file/file.c @@ -0,0 +1,276 @@ +/* + * 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 lint +static 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" +#endif + +int /* 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 + */ +int +main(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 void +unwrap(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 + */ +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 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'); +} + + +void +tryit(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); +} |
