cmp.c revision 7c2fbfb345896881c631598ee3852ce9ce33fb07
/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1992-2008 AT&T Intellectual Property *
* and is licensed under the *
* Common Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.opensource.org/licenses/cpl1.0.txt *
* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
* *
* 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) 2004-12-01 $\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.]"
"[c:print-chars?Writes control characters as a \b^\b followed by a letter of "
"the alphabet and precede characters that have the high bit set with "
"\bM-\b as with \bcat\b(1).]"
"[i:ignore-initial]#[skip:=0?Sets default skip values for the operands "
"\askip1\a and \askip2\a to \askip\a.]"
"[l:verbose?Write the decimal byte number and the differing bytes (in octal) "
"for each difference.]"
"[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>
#define CMP_VERBOSE 1
#define CMP_SILENT 2
#define CMP_CHARS 4
#define cntl(x) (x&037)
#define printchar(c) ((c) ^ ('A'-cntl('A')))
static void outchar(Sfio_t *out, register int c, int delim)
{
if(c&0200)
{
sfputc(out,'M');
sfputc(out,'-');
c &= ~0200;
}
else if(!isprint(c))
{
sfputc(out,'^');
c = printchar(c);
}
sfputc(out,c);
sfputc(out,delim);
}
/*
* compare two files
*/
static int
cmp(const char* file1, Sfio_t* f1, const char* file2, Sfio_t* f2, int flags)
{
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 ret = 0;
unsigned char* last;
for (;;)
{
if ((c1 = e1 - p1) <= 0)
{
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), "%s: EOF", file1);
}
return(ret);
}
e1 = p1 + 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), "%s: EOF", 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 (flags)
{
ret = 1;
if(flags&CMP_CHARS)
{
sfprintf(sfstdout, "%6I*d ", sizeof(pos), pos - (last - p1));
outchar(sfstdout,c1,' ');
outchar(sfstdout,*(p2-1),'\n');
}
else
sfprintf(sfstdout, "%6I*d %3o %3o\n", sizeof(pos), pos - (last - p1), c1, *(p2 - 1));
}
else
{
sfprintf(sfstdout, "%s %s differ: char %I*d, line %I*u\n", file1, file2, sizeof(pos), pos - (last - p1), sizeof(lines), lines);
return(1);
}
}
if (c1 == '\n')
lines++;
}
}
}
}
int
b_cmp(int argc, register char** argv, void* context)
{
char* s;
char* e;
Sfio_t* f1 = 0;
Sfio_t* f2 = 0;
char* file1;
char* file2;
int n;
off_t o1 = 0;
off_t o2 = 0;
struct stat s1;
struct stat s2;
int flags = 0;
NoP(argc);
cmdinit(argc, argv, context, ERROR_CATALOG, 0);
while (n = optget(argv, usage)) switch (n)
{
case 'l':
flags |= CMP_VERBOSE;
break;
case 's':
flags |= CMP_SILENT;
break;
case 'c':
flags |= CMP_CHARS;
break;
case 'i':
o1 = o2 = opt_info.num;
break;
case ':':
error(2, "%s", opt_info.arg);
break;
case '?':
error(ERROR_usage(2), "%s", opt_info.arg);
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 = strtol(s, &e, 0);
if (*e)
{
error(ERROR_exit(0), "%s: %s: invalid skip", file1, s);
goto done;
}
if (s = *argv++)
{
o2 = strtol(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), "%s: EOF", file1);
n = 1;
goto done;
}
if (o2 && sfseek(f2, o2, SEEK_SET) != o2)
{
if (!(flags & CMP_SILENT))
error(ERROR_exit(0), "%s: EOF", 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);
done:
if (f1 && f1 != sfstdin) sfclose(f1);
if (f2 && f2 != sfstdin) sfclose(f2);
return(n);
}