freebsd-nq/usr.bin/file/international.c
Joerg Wunsch 97857d5a23 Add another matching algorithhm to do heuristics for international
language text files.

Should finally close PR # bin/1925: file does not consider cyrillic
text..., though i've never got any response from the originator about
my suggestion.

While i was at it, also move out the `magic' file to /usr/share/misc,
there's nothing that magic with this file to justify its life under
/etc.
1996-12-11 14:09:12 +00:00

73 lines
2.1 KiB
C

#include "file.h"
#include <string.h>
#define F 0
#define T 1
/*
* List of characters that look "reasonable" in international
* language texts. That's almost all characters :), except a
* few in the control range of ASCII (all the known international
* charactersets share the bottom half with ASCII).
*/
static char maybe_internat[256] = {
F, F, F, F, F, F, F, F, T, T, T, T, T, T, F, F, /* 0x0X */
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 */
T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x8X */
T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x9X */
T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0xaX */
T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0xbX */
T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0xcX */
T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0xdX */
T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0xeX */
T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T /* 0xfX */
};
/* Maximal length of a line we consider "reasonable". */
#define MAXLINELEN 300
int
internatmagic(buf, nbytes)
unsigned char *buf;
int nbytes;
{
int i;
unsigned char *cp;
nbytes--;
/* First, look whether there are "unreasonable" characters. */
for (i = 0, cp = buf; i < nbytes; i++, cp++)
if (!maybe_internat[*cp])
return 0;
/*
* Now, look whether the file consists of lines of
* "reasonable" length.
*/
for (i = 0; i < nbytes;) {
cp = memchr(buf, '\n', nbytes - i);
if (cp == NULL) {
/* Don't fail if we hit the end of buffer. */
if (i + MAXLINELEN >= nbytes)
break;
else
return 0;
}
if (cp - buf > MAXLINELEN)
return 0;
i += (cp - buf + 1);
buf = cp + 1;
}
ckfputs("International language text", stdout);
return 1;
}