746 lines
21 KiB
C
746 lines
21 KiB
C
/*
|
|
* ASCII magic -- file types that we know based on keywords
|
|
* that can appear anywhere in the file.
|
|
*
|
|
* Copyright (c) Ian F. Darwin, 1987.
|
|
* Written by Ian F. Darwin.
|
|
*
|
|
* Extensively modified by Eric Fischer <enf@pobox.com> in July, 2000,
|
|
* to handle character codes other than ASCII on a unified basis.
|
|
*
|
|
* Joerg Wunsch <joerg@freebsd.org> wrote the original support for 8-bit
|
|
* international characters, now subsumed into this file.
|
|
*/
|
|
|
|
/*
|
|
* 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 "system.h"
|
|
#include "file.h"
|
|
#include "names.h"
|
|
#include "tar.h"
|
|
#include "debug.h"
|
|
|
|
FILE_RCSID("@(#)Id: ascmagic.c,v 1.32 2002/07/03 18:26:37 christos Exp ")
|
|
|
|
/*@access fmagic @*/
|
|
|
|
/*
|
|
* Stolen (by the author!) from the public domain tar program:
|
|
* Public Domain version written 26 Aug 1985 John Gilmore (ihnp4!hoptoad!gnu).
|
|
*/
|
|
#define isodigit(c) ( ((c) >= '0') && ((c) <= '7') )
|
|
|
|
/*
|
|
* Quick and dirty octal conversion.
|
|
*
|
|
* Result is -1 if the field is invalid (all blank, or nonoctal).
|
|
*/
|
|
static int
|
|
from_oct(int digs, char *where)
|
|
/*@*/
|
|
{
|
|
int value;
|
|
|
|
while (isspace((unsigned char)*where)) { /* Skip spaces */
|
|
where++;
|
|
if (--digs <= 0)
|
|
return -1; /* All blank field */
|
|
}
|
|
value = 0;
|
|
while (digs > 0 && isodigit(*where)) { /* Scan til nonoctal */
|
|
value = (value << 3) | (*where++ - '0');
|
|
--digs;
|
|
}
|
|
|
|
if (digs > 0 && *where && !isspace((unsigned char)*where))
|
|
return -1; /* Ended on non-space/nul */
|
|
|
|
return value;
|
|
}
|
|
|
|
/*
|
|
* Return
|
|
* 0 if the checksum is bad (i.e., probably not a tar archive),
|
|
* 1 for old UNIX tar file,
|
|
* 2 for Unix Std (POSIX) tar file.
|
|
*/
|
|
static int
|
|
is_tar(const fmagic fm)
|
|
/*@*/
|
|
{
|
|
int nb = fm->nb;
|
|
union record *header = (union record *)fm->buf;
|
|
int i;
|
|
int sum, recsum;
|
|
char *p;
|
|
|
|
if (nb < sizeof(*header))
|
|
return 0;
|
|
|
|
recsum = from_oct(8, header->header.chksum);
|
|
|
|
sum = 0;
|
|
p = header->charptr;
|
|
for (i = sizeof(union record); --i >= 0;) {
|
|
/*
|
|
* We can't use unsigned char here because of old compilers,
|
|
* e.g. V7.
|
|
*/
|
|
sum += 0xFF & *p++;
|
|
}
|
|
|
|
/* Adjust checksum to count the "chksum" field as blanks. */
|
|
for (i = sizeof(header->header.chksum); --i >= 0;)
|
|
sum -= 0xFF & header->header.chksum[i];
|
|
sum += ' ' * sizeof header->header.chksum;
|
|
|
|
if (sum != recsum)
|
|
return 0; /* Not a tar archive */
|
|
|
|
if (!strcmp(header->header.magic, TMAGIC))
|
|
return 2; /* Unix Standard tar archive */
|
|
|
|
return 1; /* Old fashioned tar archive */
|
|
}
|
|
typedef unsigned long unichar;
|
|
|
|
#define MAXLINELEN 300 /* longest sane line length */
|
|
#define ISSPC(x) ((x) == ' ' || (x) == '\t' || (x) == '\r' || (x) == '\n' \
|
|
|| (x) == 0x85 || (x) == '\f')
|
|
|
|
/*
|
|
* This table reflects a particular philosophy about what constitutes
|
|
* "text," and there is room for disagreement about it.
|
|
*
|
|
* Version 3.31 of the file command considered a file to be ASCII if
|
|
* each of its characters was approved by either the isascii() or
|
|
* isalpha() function. On most systems, this would mean that any
|
|
* file consisting only of characters in the range 0x00 ... 0x7F
|
|
* would be called ASCII text, but many systems might reasonably
|
|
* consider some characters outside this range to be alphabetic,
|
|
* so the file command would call such characters ASCII. It might
|
|
* have been more accurate to call this "considered textual on the
|
|
* local system" than "ASCII."
|
|
*
|
|
* It considered a file to be "International language text" if each
|
|
* of its characters was either an ASCII printing character (according
|
|
* to the real ASCII standard, not the above test), a character in
|
|
* the range 0x80 ... 0xFF, or one of the following control characters:
|
|
* backspace, tab, line feed, vertical tab, form feed, carriage return,
|
|
* escape. No attempt was made to determine the language in which files
|
|
* of this type were written.
|
|
*
|
|
*
|
|
* The table below considers a file to be ASCII if all of its characters
|
|
* are either ASCII printing characters (again, according to the X3.4
|
|
* standard, not isascii()) or any of the following controls: bell,
|
|
* backspace, tab, line feed, form feed, carriage return, esc, nextline.
|
|
*
|
|
* I include bell because some programs (particularly shell scripts)
|
|
* use it literally, even though it is rare in normal text. I exclude
|
|
* vertical tab because it never seems to be used in real text. I also
|
|
* include, with hesitation, the X3.64/ECMA-43 control nextline (0x85),
|
|
* because that's what the dd EBCDIC->ASCII table maps the EBCDIC newline
|
|
* character to. It might be more appropriate to include it in the 8859
|
|
* set instead of the ASCII set, but it's got to be included in *something*
|
|
* we recognize or EBCDIC files aren't going to be considered textual.
|
|
* Some old Unix source files use SO/SI (^N/^O) to shift between Greek
|
|
* and Latin characters, so these should possibly be allowed. But they
|
|
* make a real mess on VT100-style displays if they're not paired properly,
|
|
* so we are probably better off not calling them text.
|
|
*
|
|
* A file is considered to be ISO-8859 text if its characters are all
|
|
* either ASCII, according to the above definition, or printing characters
|
|
* from the ISO-8859 8-bit extension, characters 0xA0 ... 0xFF.
|
|
*
|
|
* Finally, a file is considered to be international text from some other
|
|
* character code if its characters are all either ISO-8859 (according to
|
|
* the above definition) or characters in the range 0x80 ... 0x9F, which
|
|
* ISO-8859 considers to be control characters but the IBM PC and Macintosh
|
|
* consider to be printing characters.
|
|
*/
|
|
|
|
#define F 0 /* character never appears in text */
|
|
#define T 1 /* character appears in plain ASCII text */
|
|
#define I 2 /* character appears in ISO-8859 text */
|
|
#define X 3 /* character appears in non-ISO extended ASCII (Mac, IBM PC) */
|
|
|
|
/*@unchecked@*/ /*@observer@*/
|
|
static char text_chars[256] = {
|
|
/* BEL BS HT LF FF CR */
|
|
F, F, F, F, F, F, F, T, T, T, T, F, T, T, F, F, /* 0x0X */
|
|
/* ESC */
|
|
F, F, F, F, F, F, F, F, F, F, F, T, F, F, F, F, /* 0x1X */
|
|
T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x2X */
|
|
T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x3X */
|
|
T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x4X */
|
|
T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x5X */
|
|
T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x6X */
|
|
T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, F, /* 0x7X */
|
|
/* NEL */
|
|
X, X, X, X, X, T, X, X, X, X, X, X, X, X, X, X, /* 0x8X */
|
|
X, X, X, X, X, X, X, X, X, X, X, X, X, X, X, X, /* 0x9X */
|
|
I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xaX */
|
|
I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xbX */
|
|
I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xcX */
|
|
I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xdX */
|
|
I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xeX */
|
|
I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I /* 0xfX */
|
|
};
|
|
|
|
static int
|
|
looks_ascii(const unsigned char *buf, int nb,
|
|
/*@out@*/ unichar *ubuf, /*@out@*/ int *ulen)
|
|
/*@modifies *ubuf, *ulen @*/
|
|
{
|
|
int i;
|
|
|
|
*ulen = 0;
|
|
|
|
for (i = 0; i < nb; i++) {
|
|
int t = text_chars[buf[i]];
|
|
|
|
if (t != T)
|
|
return 0;
|
|
|
|
ubuf[(*ulen)++] = buf[i];
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
looks_latin1(const unsigned char *buf, int nb,
|
|
/*@out@*/ unichar *ubuf, /*@out@*/ int *ulen)
|
|
/*@modifies *ubuf, *ulen @*/
|
|
{
|
|
int i;
|
|
|
|
*ulen = 0;
|
|
|
|
for (i = 0; i < nb; i++) {
|
|
int t = text_chars[buf[i]];
|
|
|
|
if (t != T && t != I)
|
|
return 0;
|
|
|
|
ubuf[(*ulen)++] = buf[i];
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
looks_extended(const unsigned char *buf, int nb,
|
|
/*@out@*/ unichar *ubuf, /*@out@*/ int *ulen)
|
|
/*@modifies *ubuf, *ulen @*/
|
|
{
|
|
int i;
|
|
|
|
*ulen = 0;
|
|
|
|
for (i = 0; i < nb; i++) {
|
|
int t = text_chars[buf[i]];
|
|
|
|
if (t != T && t != I && t != X)
|
|
return 0;
|
|
|
|
ubuf[(*ulen)++] = buf[i];
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
looks_utf8(const unsigned char *buf, int nb,
|
|
/*@out@*/ unichar *ubuf, /*@out@*/ int *ulen)
|
|
/*@modifies *ubuf, *ulen @*/
|
|
{
|
|
int i, n;
|
|
unichar c;
|
|
int gotone = 0;
|
|
|
|
*ulen = 0;
|
|
|
|
for (i = 0; i < nb; i++) {
|
|
if ((buf[i] & 0x80) == 0) { /* 0xxxxxxx is plain ASCII */
|
|
/*
|
|
* Even if the whole file is valid UTF-8 sequences,
|
|
* still reject it if it uses weird control characters.
|
|
*/
|
|
|
|
if (text_chars[buf[i]] != T)
|
|
return 0;
|
|
|
|
ubuf[(*ulen)++] = buf[i];
|
|
} else if ((buf[i] & 0x40) == 0) { /* 10xxxxxx never 1st byte */
|
|
return 0;
|
|
} else { /* 11xxxxxx begins UTF-8 */
|
|
int following;
|
|
|
|
if ((buf[i] & 0x20) == 0) { /* 110xxxxx */
|
|
c = buf[i] & 0x1f;
|
|
following = 1;
|
|
} else if ((buf[i] & 0x10) == 0) { /* 1110xxxx */
|
|
c = buf[i] & 0x0f;
|
|
following = 2;
|
|
} else if ((buf[i] & 0x08) == 0) { /* 11110xxx */
|
|
c = buf[i] & 0x07;
|
|
following = 3;
|
|
} else if ((buf[i] & 0x04) == 0) { /* 111110xx */
|
|
c = buf[i] & 0x03;
|
|
following = 4;
|
|
} else if ((buf[i] & 0x02) == 0) { /* 1111110x */
|
|
c = buf[i] & 0x01;
|
|
following = 5;
|
|
} else
|
|
return 0;
|
|
|
|
for (n = 0; n < following; n++) {
|
|
i++;
|
|
if (i >= nb)
|
|
goto done;
|
|
|
|
if ((buf[i] & 0x80) == 0 || (buf[i] & 0x40))
|
|
return 0;
|
|
|
|
c = (c << 6) + (buf[i] & 0x3f);
|
|
}
|
|
|
|
ubuf[(*ulen)++] = c;
|
|
gotone = 1;
|
|
}
|
|
}
|
|
done:
|
|
return gotone; /* don't claim it's UTF-8 if it's all 7-bit */
|
|
}
|
|
|
|
static int
|
|
looks_unicode(const unsigned char *buf, int nb,
|
|
/*@out@*/ unichar *ubuf, /*@out@*/ int *ulen)
|
|
/*@modifies *ubuf, *ulen @*/
|
|
{
|
|
int bigend;
|
|
int i;
|
|
|
|
if (nb < 2)
|
|
return 0;
|
|
|
|
if (buf[0] == 0xff && buf[1] == 0xfe)
|
|
bigend = 0;
|
|
else if (buf[0] == 0xfe && buf[1] == 0xff)
|
|
bigend = 1;
|
|
else
|
|
return 0;
|
|
|
|
*ulen = 0;
|
|
|
|
for (i = 2; i + 1 < nb; i += 2) {
|
|
/* XXX fix to properly handle chars > 65536 */
|
|
|
|
if (bigend)
|
|
ubuf[(*ulen)++] = buf[i + 1] + 256 * buf[i];
|
|
else
|
|
ubuf[(*ulen)++] = buf[i] + 256 * buf[i + 1];
|
|
|
|
if (ubuf[*ulen - 1] == 0xfffe)
|
|
return 0;
|
|
if (ubuf[*ulen - 1] < 128 && text_chars[ubuf[*ulen - 1]] != T)
|
|
return 0;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
#undef F
|
|
#undef T
|
|
#undef I
|
|
#undef X
|
|
|
|
/*
|
|
* This table maps each EBCDIC character to an (8-bit extended) ASCII
|
|
* character, as specified in the rationale for the dd(1) command in
|
|
* draft 11.2 (September, 1991) of the POSIX P1003.2 standard.
|
|
*
|
|
* Unfortunately it does not seem to correspond exactly to any of the
|
|
* five variants of EBCDIC documented in IBM's _Enterprise Systems
|
|
* Architecture/390: Principles of Operation_, SA22-7201-06, Seventh
|
|
* Edition, July, 1999, pp. I-1 - I-4.
|
|
*
|
|
* Fortunately, though, all versions of EBCDIC, including this one, agree
|
|
* on most of the printing characters that also appear in (7-bit) ASCII.
|
|
* Of these, only '|', '!', '~', '^', '[', and ']' are in question at all.
|
|
*
|
|
* Fortunately too, there is general agreement that codes 0x00 through
|
|
* 0x3F represent control characters, 0x41 a nonbreaking space, and the
|
|
* remainder printing characters.
|
|
*
|
|
* This is sufficient to allow us to identify EBCDIC text and to distinguish
|
|
* between old-style and internationalized examples of text.
|
|
*/
|
|
|
|
/*@unchecked@*/ /*@observer@*/
|
|
static unsigned char ebcdic_to_ascii[] = {
|
|
0, 1, 2, 3, 156, 9, 134, 127, 151, 141, 142, 11, 12, 13, 14, 15,
|
|
16, 17, 18, 19, 157, 133, 8, 135, 24, 25, 146, 143, 28, 29, 30, 31,
|
|
128, 129, 130, 131, 132, 10, 23, 27, 136, 137, 138, 139, 140, 5, 6, 7,
|
|
144, 145, 22, 147, 148, 149, 150, 4, 152, 153, 154, 155, 20, 21, 158, 26,
|
|
' ', 160, 161, 162, 163, 164, 165, 166, 167, 168, 213, '.', '<', '(', '+', '|',
|
|
'&', 169, 170, 171, 172, 173, 174, 175, 176, 177, '!', '$', '*', ')', ';', '~',
|
|
'-', '/', 178, 179, 180, 181, 182, 183, 184, 185, 203, ',', '%', '_', '>', '?',
|
|
186, 187, 188, 189, 190, 191, 192, 193, 194, '`', ':', '#', '@', '\'','=', '"',
|
|
195, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 196, 197, 198, 199, 200, 201,
|
|
202, 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', '^', 204, 205, 206, 207, 208,
|
|
209, 229, 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 210, 211, 212, '[', 214, 215,
|
|
216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, ']', 230, 231,
|
|
'{', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 232, 233, 234, 235, 236, 237,
|
|
'}', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 238, 239, 240, 241, 242, 243,
|
|
'\\',159, 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 244, 245, 246, 247, 248, 249,
|
|
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 250, 251, 252, 253, 254, 255
|
|
};
|
|
|
|
/*
|
|
* The following EBCDIC-to-ASCII table may relate more closely to reality,
|
|
* or at least to modern reality. It comes from
|
|
*
|
|
* http://ftp.s390.ibm.com/products/oe/bpxqp9.html
|
|
*
|
|
* and maps the characters of EBCDIC code page 1047 (the code used for
|
|
* Unix-derived software on IBM's 390 systems) to the corresponding
|
|
* characters from ISO 8859-1.
|
|
*
|
|
* If this table is used instead of the above one, some of the special
|
|
* cases for the NEL character can be taken out of the code.
|
|
*/
|
|
|
|
/*@unchecked@*/ /*@unused@*/ /*@observer@*/
|
|
static unsigned char ebcdic_1047_to_8859[] = {
|
|
0x00,0x01,0x02,0x03,0x9C,0x09,0x86,0x7F,0x97,0x8D,0x8E,0x0B,0x0C,0x0D,0x0E,0x0F,
|
|
0x10,0x11,0x12,0x13,0x9D,0x0A,0x08,0x87,0x18,0x19,0x92,0x8F,0x1C,0x1D,0x1E,0x1F,
|
|
0x80,0x81,0x82,0x83,0x84,0x85,0x17,0x1B,0x88,0x89,0x8A,0x8B,0x8C,0x05,0x06,0x07,
|
|
0x90,0x91,0x16,0x93,0x94,0x95,0x96,0x04,0x98,0x99,0x9A,0x9B,0x14,0x15,0x9E,0x1A,
|
|
0x20,0xA0,0xE2,0xE4,0xE0,0xE1,0xE3,0xE5,0xE7,0xF1,0xA2,0x2E,0x3C,0x28,0x2B,0x7C,
|
|
0x26,0xE9,0xEA,0xEB,0xE8,0xED,0xEE,0xEF,0xEC,0xDF,0x21,0x24,0x2A,0x29,0x3B,0x5E,
|
|
0x2D,0x2F,0xC2,0xC4,0xC0,0xC1,0xC3,0xC5,0xC7,0xD1,0xA6,0x2C,0x25,0x5F,0x3E,0x3F,
|
|
0xF8,0xC9,0xCA,0xCB,0xC8,0xCD,0xCE,0xCF,0xCC,0x60,0x3A,0x23,0x40,0x27,0x3D,0x22,
|
|
0xD8,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0xAB,0xBB,0xF0,0xFD,0xFE,0xB1,
|
|
0xB0,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,0x70,0x71,0x72,0xAA,0xBA,0xE6,0xB8,0xC6,0xA4,
|
|
0xB5,0x7E,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0xA1,0xBF,0xD0,0x5B,0xDE,0xAE,
|
|
0xAC,0xA3,0xA5,0xB7,0xA9,0xA7,0xB6,0xBC,0xBD,0xBE,0xDD,0xA8,0xAF,0x5D,0xB4,0xD7,
|
|
0x7B,0x41,0x42,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0xAD,0xF4,0xF6,0xF2,0xF3,0xF5,
|
|
0x7D,0x4A,0x4B,0x4C,0x4D,0x4E,0x4F,0x50,0x51,0x52,0xB9,0xFB,0xFC,0xF9,0xFA,0xFF,
|
|
0x5C,0xF7,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5A,0xB2,0xD4,0xD6,0xD2,0xD3,0xD5,
|
|
0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0xB3,0xDB,0xDC,0xD9,0xDA,0x9F
|
|
};
|
|
|
|
/*
|
|
* Copy buf[0 ... nb-1] into out[], translating EBCDIC to ASCII.
|
|
*/
|
|
static void
|
|
from_ebcdic(const unsigned char *buf, int nb, /*@out@*/ unsigned char *otp)
|
|
/*@modifies *otp @*/
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < nb; i++) {
|
|
otp[i] = ebcdic_to_ascii[buf[i]];
|
|
}
|
|
}
|
|
|
|
static int
|
|
fmagicAMatch(const unsigned char *s, const unichar *us, int ulen)
|
|
/*@*/
|
|
{
|
|
size_t i;
|
|
|
|
for (i = 0; i < ulen; i++) {
|
|
if (s[i] != us[i])
|
|
return 0;
|
|
}
|
|
|
|
if (s[i])
|
|
return 0;
|
|
else
|
|
return 1;
|
|
}
|
|
|
|
/* int nb: size actually read */
|
|
int
|
|
fmagicA(fmagic fm)
|
|
{
|
|
unsigned char * buf = fm->buf;
|
|
int nb = fm->nb;
|
|
|
|
char nbuf[HOWMANY+1]; /* one extra for terminating '\0' */
|
|
unichar ubuf[HOWMANY+1]; /* one extra for terminating '\0' */
|
|
int ulen;
|
|
struct names *p;
|
|
int i;
|
|
|
|
char *code = NULL;
|
|
char *code_mime = NULL;
|
|
char *type = NULL;
|
|
char *subtype = NULL;
|
|
char *subtype_mime = NULL;
|
|
|
|
int has_escapes = 0;
|
|
int has_backspace = 0;
|
|
|
|
int n_crlf = 0;
|
|
int n_lf = 0;
|
|
int n_cr = 0;
|
|
int n_nel = 0;
|
|
|
|
int last_line_end = -1;
|
|
int has_long_lines = 0;
|
|
|
|
/*
|
|
* 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(fm)) {
|
|
case 1:
|
|
ckfputs(((fm->flags & FMAGIC_FLAGS_MIME)
|
|
? "application/x-tar" : "tar archive"), fm);
|
|
return 1;
|
|
case 2:
|
|
ckfputs(((fm->flags & FMAGIC_FLAGS_MIME)
|
|
? "application/x-tar, POSIX" : "POSIX tar archive"), fm);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Undo the NUL-termination kindly provided by fmagicProcess()
|
|
* but leave at least one byte to look at
|
|
*/
|
|
|
|
while (nb > 1 && buf[nb - 1] == '\0')
|
|
nb--;
|
|
|
|
/*
|
|
* Then try to determine whether it's any character code we can
|
|
* identify. Each of these tests, if it succeeds, will leave
|
|
* the text converted into one-unichar-per-character Unicode in
|
|
* ubuf, and the number of characters converted in ulen.
|
|
*/
|
|
if (looks_ascii(buf, nb, ubuf, &ulen)) {
|
|
code = "ASCII";
|
|
code_mime = "us-ascii";
|
|
type = "text";
|
|
} else if (looks_utf8(buf, nb, ubuf, &ulen)) {
|
|
code = "UTF-8 Unicode";
|
|
code_mime = "utf-8";
|
|
type = "text";
|
|
} else if ((i = looks_unicode(buf, nb, ubuf, &ulen))) {
|
|
if (i == 1)
|
|
code = "Little-endian UTF-16 Unicode";
|
|
else
|
|
code = "Big-endian UTF-16 Unicode";
|
|
|
|
type = "character data";
|
|
code_mime = "utf-16"; /* is this defined? */
|
|
} else if (looks_latin1(buf, nb, ubuf, &ulen)) {
|
|
code = "ISO-8859";
|
|
type = "text";
|
|
code_mime = "iso-8859-1";
|
|
} else if (looks_extended(buf, nb, ubuf, &ulen)) {
|
|
code = "Non-ISO extended-ASCII";
|
|
type = "text";
|
|
code_mime = "unknown";
|
|
} else {
|
|
from_ebcdic(buf, nb, nbuf);
|
|
|
|
if (looks_ascii(nbuf, nb, ubuf, &ulen)) {
|
|
code = "EBCDIC";
|
|
type = "character data";
|
|
code_mime = "ebcdic";
|
|
} else if (looks_latin1(nbuf, nb, ubuf, &ulen)) {
|
|
code = "International EBCDIC";
|
|
type = "character data";
|
|
code_mime = "ebcdic";
|
|
} else {
|
|
return 0; /* doesn't look like text at all */
|
|
}
|
|
}
|
|
|
|
/*
|
|
* for troff, look for . + letter + letter or .\";
|
|
* this must be done to disambiguate tar archives' ./file
|
|
* and other trash from real troff input.
|
|
*
|
|
* I believe Plan 9 troff allows non-ASCII characters in the names
|
|
* of macros, so this test might possibly fail on such a file.
|
|
*/
|
|
if (*ubuf == '.') {
|
|
unichar *tp = ubuf + 1;
|
|
|
|
while (ISSPC(*tp))
|
|
++tp; /* skip leading whitespace */
|
|
if ((tp[0] == '\\' && tp[1] == '\"') ||
|
|
(isascii(tp[0]) && isalnum(tp[0]) &&
|
|
isascii(tp[1]) && isalnum(tp[1]) &&
|
|
ISSPC(tp[2]))) {
|
|
subtype_mime = "text/troff";
|
|
subtype = "troff or preprocessor input";
|
|
goto subtype_identified;
|
|
}
|
|
}
|
|
|
|
if ((*buf == 'c' || *buf == 'C') && ISSPC(buf[1])) {
|
|
subtype_mime = "text/fortran";
|
|
subtype = "fortran program";
|
|
goto subtype_identified;
|
|
}
|
|
|
|
/* look for tokens from names.h - this is expensive! */
|
|
|
|
i = 0;
|
|
while (i < ulen) {
|
|
int end;
|
|
|
|
/*
|
|
* skip past any leading space
|
|
*/
|
|
while (i < ulen && ISSPC(ubuf[i]))
|
|
i++;
|
|
if (i >= ulen)
|
|
break;
|
|
|
|
/*
|
|
* find the next whitespace
|
|
*/
|
|
for (end = i + 1; end < nb; end++)
|
|
if (ISSPC(ubuf[end]))
|
|
/*@innerbreak@*/ break;
|
|
|
|
/*
|
|
* compare the word thus isolated against the token list
|
|
*/
|
|
for (p = names; p < names + NNAMES; p++) {
|
|
if (fmagicAMatch(p->name, ubuf + i, end - i)) {
|
|
subtype = types[p->type].human;
|
|
subtype_mime = types[p->type].mime;
|
|
goto subtype_identified;
|
|
}
|
|
}
|
|
|
|
i = end;
|
|
}
|
|
|
|
subtype_identified:
|
|
|
|
/*
|
|
* Now try to discover other details about the file.
|
|
*/
|
|
for (i = 0; i < ulen; i++) {
|
|
if (i > last_line_end + MAXLINELEN)
|
|
has_long_lines = 1;
|
|
|
|
if (ubuf[i] == '\033')
|
|
has_escapes = 1;
|
|
if (ubuf[i] == '\b')
|
|
has_backspace = 1;
|
|
|
|
if (ubuf[i] == '\r' && (i + 1 < ulen && ubuf[i + 1] == '\n')) {
|
|
n_crlf++;
|
|
last_line_end = i;
|
|
}
|
|
if (ubuf[i] == '\r' && (i + 1 >= ulen || ubuf[i + 1] != '\n')) {
|
|
n_cr++;
|
|
last_line_end = i;
|
|
}
|
|
if (ubuf[i] == '\n' && (i - 1 < 0 || ubuf[i - 1] != '\r')) {
|
|
n_lf++;
|
|
last_line_end = i;
|
|
}
|
|
if (ubuf[i] == 0x85) { /* X3.64/ECMA-43 "next line" character */
|
|
n_nel++;
|
|
last_line_end = i;
|
|
}
|
|
}
|
|
|
|
if ((fm->flags & FMAGIC_FLAGS_MIME)) {
|
|
if (subtype_mime != NULL)
|
|
ckfputs(subtype_mime, fm);
|
|
else
|
|
ckfputs("text/plain", fm);
|
|
|
|
if (code_mime != NULL) {
|
|
ckfputs("; charset=", fm);
|
|
ckfputs(code_mime, fm);
|
|
}
|
|
} else {
|
|
ckfputs(code, fm);
|
|
|
|
if (subtype != NULL) {
|
|
ckfputs(" ", fm);
|
|
ckfputs(subtype, fm);
|
|
}
|
|
ckfputs(" ", fm);
|
|
ckfputs(type, fm);
|
|
|
|
if (has_long_lines)
|
|
ckfputs(", with very long lines", fm);
|
|
|
|
/*
|
|
* Only report line terminators if we find one other than LF,
|
|
* or if we find none at all.
|
|
*/
|
|
if ((n_crlf == 0 && n_cr == 0 && n_nel == 0 && n_lf == 0) ||
|
|
(n_crlf != 0 || n_cr != 0 || n_nel != 0)) {
|
|
ckfputs(", with", fm);
|
|
|
|
if (n_crlf == 0 && n_cr == 0 && n_nel == 0 && n_lf == 0)
|
|
ckfputs(" no", fm);
|
|
else {
|
|
if (n_crlf) {
|
|
ckfputs(" CRLF", fm);
|
|
if (n_cr || n_lf || n_nel)
|
|
ckfputs(",", fm);
|
|
}
|
|
if (n_cr) {
|
|
ckfputs(" CR", fm);
|
|
if (n_lf || n_nel)
|
|
ckfputs(",", fm);
|
|
}
|
|
if (n_lf) {
|
|
ckfputs(" LF", fm);
|
|
if (n_nel)
|
|
ckfputs(",", fm);
|
|
}
|
|
if (n_nel)
|
|
ckfputs(" NEL", fm);
|
|
}
|
|
|
|
ckfputs(" line terminators", fm);
|
|
}
|
|
|
|
if (has_escapes)
|
|
ckfputs(", with escape sequences", fm);
|
|
if (has_backspace)
|
|
ckfputs(", with overstriking", fm);
|
|
}
|
|
|
|
return 1;
|
|
}
|