/***********************************************************************

*                                                                      *

*               This software is part of the ast package               *

*          Copyright (c) 1992-2012 AT&T Intellectual Property          *

*                      and is licensed under the                       *

*                 Eclipse Public License, Version 1.0                  *

*                    by AT&T Intellectual Property                     *

*                                                                      *

*                A copy of the License is available at                 *

*          http://www.eclipse.org/org/documents/epl-v10.html           *

*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *

*                                                                      *

*              Information and Software Systems Research               *

*                            AT&T Research                             *

*                           Florham Park NJ                            *

*                                                                      *

*                 Glenn Fowler <gsf@research.att.com>                  *

*                  David Korn <dgk@research.att.com>                   *

*                                                                      *

***********************************************************************/

#pragma prototyped

/*

 * David Korn

 * Glenn Fowler

 * AT&T Bell Laboratories

 *

 * cmp

 */

static const char usage[] =

"[-?\n@(#)$Id: cmp (AT&T Research) 2010-04-11 $\n]"

USAGE_LICENSE

"[+NAME?cmp - compare two files]"

"[+DESCRIPTION?\bcmp\b compares two files \afile1\a and \afile2\a. "

    "\bcmp\b writes no output if the files are the same. By default, if the "

    "files differ, the byte and line number at which the first difference "

    "occurred are written to standard output. Bytes and lines are numbered "

    "beginning with 1.]"

"[+?If \askip1\a or \askip2\a are specified, or the \b-i\b option is "

    "specified, initial bytes of the corresponding file are skipped before "

    "beginning the compare. The skip values are in bytes or can have a "

    "suffix of \bk\b for kilobytes or \bm\b for megabytes.]"

"[+?If either \afile1\a or \afiles2\a is \b-\b, \bcmp\b uses standard "

    "input starting at the current location.]"

"[b:print-bytes?Print differing bytes as 3 digit octal values.]"

"[c:print-chars?Print differing bytes as follows: non-space printable "

    "characters as themselves; space and control characters as \b^\b "

    "followed by a letter of the alphabet; and characters with the high bit "

    "set as the lower 7 bit character prefixed by \bM^\b for 7 bit space and "

    "non-printable characters and \bM-\b for all other characters. If the 7 "

    "bit character encoding is not ASCII then the characters are converted "

    "to ASCII to determine \ahigh bit set\a, and if set it is cleared and "

    "converted back to the native encoding. Multibyte characters in the "

    "current locale are treated as printable characters.]"

"[d:differences?Print at most \adifferences\a differences using "

    "\b--verbose\b output format. \b--differences=0\b is equivalent to "

    "\b--silent\b.]#[differences]"

"[i:ignore-initial|skip?Skip the the first \askip1\a bytes in \afile1\a "

    "and the first \askip2\a bytes in \afile2\a. If \askip2\a is omitted "

    "then \askip1\a is used.]:[skip1[::skip2]]:=0::0]"

"[l:verbose?Write the decimal byte number and the differing bytes (in "

    "octal) for each difference.]"

"[n:count|bytes?Compare at most \acount\a bytes.]#[count]"

"[s:quiet|silent?Write nothing for differing files; return non-zero exit "

    "status only.]"

"\n"

"\nfile1 file2 [skip1 [skip2]]\n"

"\n"

"[+EXIT STATUS?]"

    "{"

        "[+0?The files or portions compared are identical.]"

        "[+1?The files are different.]"

        "[+>1?An error occurred.]"

    "}"

"[+SEE ALSO?\bcomm\b(1), \bdiff\b(1), \bcat\b(1)]"

;

#include <cmd.h>

#include <ls.h>

#include <ctype.h>

#include <ccode.h>

#define CMP_VERBOSE	0x01

#define CMP_SILENT	0x02

#define CMP_CHARS	0x04

#define CMP_BYTES	0x08

static void

pretty(Sfio_t *out, int o, int delim, int flags)

{

	int	c;

	int	m;

	char*	s;

	char	buf[10];

	s = buf;

	if ((flags & CMP_BYTES) || !(flags & CMP_CHARS))

	{

		*s++ = ' ';

		if ((flags & CMP_CHARS) && delim != -1)

			*s++ = ' ';

		*s++ = '0' + ((o >> 6) & 07);

		*s++ = '0' + ((o >> 3) & 07);

		*s++ = '0' + (o & 07);

	}

	if (flags & CMP_CHARS)

	{

		*s++ = ' ';

		c = ccmapc(o, CC_NATIVE, CC_ASCII);

		if (c & 0x80)

		{

			m = 1;

			*s++ = 'M';

			c &= 0x7f;

			o = ccmapc(c, CC_ASCII, CC_NATIVE);

		}

		else

			m = 0;

		if (isspace(o) || !isprint(o))

		{

			if (!m)

				*s++ = ' ';

			*s++ = '^';

			c ^= 0x40;

			o = ccmapc(c, CC_ASCII, CC_NATIVE);

		}

		else if (m)

			*s++ = '-';

		else

		{

			*s++ = ' ';

			*s++ = ' ';

		}

		*s++ = o;

	}

	*s = 0;

	sfputr(out, buf, delim);

}

/*

 * compare two files

 */

static int

cmp(const char* file1, Sfio_t* f1, const char* file2, Sfio_t* f2, int flags, Sfoff_t count, Sfoff_t differences)

{

	register int		c1;

	register int		c2;

	register unsigned char*	p1 = 0;

	register unsigned char*	p2 = 0;

	register Sfoff_t	lines = 1;

	register unsigned char*	e1 = 0;

	register unsigned char*	e2 = 0;

	Sfoff_t			pos = 0;

	int			n1 = 0;

	int			ret = 0;

	unsigned char*		last;

	for (;;)

	{

		if ((c1 = e1 - p1) <= 0)

		{

			if (count > 0 && !(count -= n1))

				return ret;

			if (!(p1 = (unsigned char*)sfreserve(f1, SF_UNBOUND, 0)) || (c1 = sfvalue(f1)) <= 0)

			{

				if ((e2 - p2) > 0 || sfreserve(f2, SF_UNBOUND, 0) && sfvalue(f2) > 0)

				{

					ret = 1;

					if (!(flags & CMP_SILENT))

						error(ERROR_exit(1), "EOF on %s", file1);

				}

				return ret;

			}

			if (count > 0 && c1 > count)

				c1 = (int)count;

			e1 = p1 + c1;

			n1 = c1;

		}

		if ((c2 = e2 - p2) <= 0)

		{

			if (!(p2 = (unsigned char*)sfreserve(f2, SF_UNBOUND, 0)) || (c2 = sfvalue(f2)) <= 0)

			{

				if (!(flags & CMP_SILENT))

					error(ERROR_exit(1), "EOF on %s", file2);

				return 1;

			}

			e2 = p2 + c2;

		}

		if (c1 > c2)

			c1 = c2;

		pos += c1;

		if (flags & CMP_SILENT)

		{

			if (memcmp(p1, p2, c1))

				return 1;

			p1 += c1;

			p2 += c1;

		}

		else

		{

			last = p1 + c1;

			while (p1 < last)

			{

				if ((c1 = *p1++) != *p2++)

				{

					if (differences >= 0)

					{

						if (!differences)

							return 1;

						differences--;

					}

#if 0

					if (!flags)

						sfprintf(sfstdout, "%s %s differ: char %I*d, line %I*u\n", file1, file2, sizeof(pos), pos - (last - p1), sizeof(lines), lines);

					else

					{

						sfprintf(sfstdout, "%6I*d", sizeof(pos), pos - (last - p1));

						pretty(sfstdout, c1, -1, flags);

						pretty(sfstdout, *(p2-1), '\n', flags);

					}

#else

					if (flags & CMP_VERBOSE)

						sfprintf(sfstdout, "%6I*d", sizeof(pos), pos - (last - p1));

					else

						sfprintf(sfstdout, "%s %s differ: char %I*d, line %I*u", file1, file2, sizeof(pos), pos - (last - p1), sizeof(lines), lines);

					if (flags & (CMP_BYTES|CMP_CHARS|CMP_VERBOSE))

					{

						sfputc(sfstdout, (flags & CMP_VERBOSE) ? ' ' : ',');

						pretty(sfstdout, c1, -1, flags);

						pretty(sfstdout, *(p2-1), '\n', flags);

					}

					else

						sfputc(sfstdout, '\n');

#endif

					if (!differences || differences < 0 && !(flags & CMP_VERBOSE))

						return 1;

					ret = 1;

				}

				if (c1 == '\n')

					lines++;

			}

		}

	}

}

int

b_cmp(int argc, register char** argv, Shbltin_t* context)

{

	char*		s;

	char*		e;

	char*		file1;

	char*		file2;

	int		n;

	struct stat	s1;

	struct stat	s2;

	Sfio_t*		f1 = 0;

	Sfio_t*		f2 = 0;

	Sfoff_t		o1 = 0;

	Sfoff_t		o2 = 0;

	Sfoff_t		count = -1;

	Sfoff_t		differences = -1;

	int		flags = 0;

	NoP(argc);

	cmdinit(argc, argv, context, ERROR_CATALOG, 0);

	for (;;)

	{

		switch (optget(argv, usage))

		{

		case 'b':

			flags |= CMP_BYTES;

			continue;

		case 'c':

			flags |= CMP_CHARS;

			continue;

		case 'd':

			flags |= CMP_VERBOSE;

			differences = opt_info.number;

			continue;

		case 'i':

			o1 = strtoll(opt_info.arg, &e, 0);

			if (*e == ':')

				o2 = strtoll(e + 1, &e, 0);

			else

				o2 = o1;

			if (*e)

			{

				error(2, "%s: skip1:skip2 expected", opt_info.arg);

				break;

			}

			continue;

		case 'l':

			flags |= CMP_VERBOSE;

			continue;

		case 'n':

			count = opt_info.number;

			continue;

		case 's':

			flags |= CMP_SILENT;

			continue;

		case ':':

			error(2, "%s", opt_info.arg);

			break;

		case '?':

			error(ERROR_usage(2), "%s", opt_info.arg);

			break;

		}

		break;

	}

	argv += opt_info.index;

	if (error_info.errors || !(file1 = *argv++) || !(file2 = *argv++))

		error(ERROR_usage(2), "%s", optusage(NiL));

	n = 2;

	if (streq(file1, "-"))

		f1 = sfstdin;

	else if (!(f1 = sfopen(NiL, file1, "r")))

	{

		if (!(flags & CMP_SILENT))

			error(ERROR_system(0), "%s: cannot open", file1);

		goto done;

	}

	if (streq(file2, "-"))

		f2 = sfstdin;

	else if (!(f2 = sfopen(NiL, file2, "r")))

	{

		if (!(flags & CMP_SILENT))

			error(ERROR_system(0), "%s: cannot open", file2);

		goto done;

	}

	if (s = *argv++)

	{

		o1 = strtoll(s, &e, 0);

		if (*e)

		{

			error(ERROR_exit(0), "%s: %s: invalid skip", file1, s);

			goto done;

		}

		if (s = *argv++)

		{

			o2 = strtoll(s, &e, 0);

			if (*e)

			{

				error(ERROR_exit(0), "%s: %s: invalid skip", file2, s);

				goto done;

			}

		}

		if (*argv)

		{

			error(ERROR_usage(0), "%s", optusage(NiL));

			goto done;

		}

	}

	if (o1 && sfseek(f1, o1, SEEK_SET) != o1)

	{

		if (!(flags & CMP_SILENT))

			error(ERROR_exit(0), "EOF on %s", file1);

		n = 1;

		goto done;

	}

	if (o2 && sfseek(f2, o2, SEEK_SET) != o2)

	{

		if (!(flags & CMP_SILENT))

			error(ERROR_exit(0), "EOF on %s", file2);

		n = 1;

		goto done;

	}

	if (fstat(sffileno(f1), &s1))

		error(ERROR_system(0), "%s: cannot stat", file1);

	else if (fstat(sffileno(f2), &s2))

		error(ERROR_system(0), "%s: cannot stat", file1);

	else if (s1.st_ino == s2.st_ino && s1.st_dev == s2.st_dev && o1 == o2)

		n = 0;

	else

		n = ((flags & CMP_SILENT) && S_ISREG(s1.st_mode) && S_ISREG(s2.st_mode) && (s1.st_size - o1) != (s2.st_size - o2)) ? 1 : cmp(file1, f1, file2, f2, flags, count, differences);

 done:

	if (f1 && f1 != sfstdin)

		sfclose(f1);

	if (f2 && f2 != sfstdin)

		sfclose(f2);

	return n;

}