diff options
Diffstat (limited to 'contrib/file/is_tar.c')
| -rw-r--r-- | contrib/file/is_tar.c | 76 |
1 files changed, 66 insertions, 10 deletions
diff --git a/contrib/file/is_tar.c b/contrib/file/is_tar.c index de7a169..fbee318 100644 --- a/contrib/file/is_tar.c +++ b/contrib/file/is_tar.c @@ -1,29 +1,85 @@ /* + * Copyright (c) Ian F. Darwin 1986-1995. + * Software written by Ian F. Darwin and others; + * maintained 1995-present by Christos Zoulas and others. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice immediately at the beginning of the file, without modification, + * this list of conditions, and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by Ian F. Darwin and others. + * 4. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR + * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ +/* * is_tar() -- figure out whether file is a tar archive. * * Stolen (by the author!) from the public domain tar program: * Public Domain version written 26 Aug 1985 John Gilmore (ihnp4!hoptoad!gnu). * * @(#)list.c 1.18 9/23/86 Public Domain - gnu - * $Id: is_tar.c,v 1.17 2002/07/03 18:26:38 christos Exp $ * * Comments changed and some code/comments reformatted * for file command by Ian Darwin. */ #include "file.h" +#include "magic.h" #include <string.h> #include <ctype.h> #include <sys/types.h> #include "tar.h" #ifndef lint -FILE_RCSID("@(#)$Id: is_tar.c,v 1.17 2002/07/03 18:26:38 christos Exp $") +FILE_RCSID("@(#)$Id: is_tar.c,v 1.24 2003/11/11 20:01:46 christos Exp $") #endif #define isodigit(c) ( ((c) >= '0') && ((c) <= '7') ) -static int from_oct(int, char *); /* Decode octal number */ +private int is_tar(const unsigned char *, size_t); +private int from_oct(int, const char *); /* Decode octal number */ + +protected int +file_is_tar(struct magic_set *ms, const unsigned char *buf, size_t nbytes) +{ + /* + * Do the tar test first, because if the first file in the tar + * archive starts with a dot, we can confuse it with an nroff file. + */ + switch (is_tar(buf, nbytes)) { + case 1: + if (file_printf(ms, (ms->flags & MAGIC_MIME) ? + "application/x-tar" : "tar archive") == -1) + return -1; + return 1; + case 2: + if (file_printf(ms, (ms->flags & MAGIC_MIME) ? + "application/x-tar, POSIX" : "POSIX tar archive") == -1) + return -1; + return 1; + default: + return 0; + } +} /* * Return @@ -31,13 +87,13 @@ static int from_oct(int, char *); /* Decode octal number */ * 1 for old UNIX tar file, * 2 for Unix Std (POSIX) tar file. */ -int -is_tar(unsigned char *buf, int nbytes) +private int +is_tar(const unsigned char *buf, size_t nbytes) { - union record *header = (union record *)buf; + const union record *header = (const union record *)(const void *)buf; int i; int sum, recsum; - char *p; + const char *p; if (nbytes < sizeof(union record)) return 0; @@ -48,7 +104,7 @@ is_tar(unsigned char *buf, int nbytes) p = header->charptr; for (i = sizeof(union record); --i >= 0;) { /* - * We can't use unsigned char here because of old compilers, + * We cannot use unsigned char here because of old compilers, * e.g. V7. */ sum += 0xFF & *p++; @@ -74,8 +130,8 @@ is_tar(unsigned char *buf, int nbytes) * * Result is -1 if the field is invalid (all blank, or nonoctal). */ -static int -from_oct(int digs, char *where) +private int +from_oct(int digs, const char *where) { int value; |
