1 #include <u.h>
2 #include <libc.h>
3 
4 #define		BUF		65536
5 
6 int sflag = 0;
7 int lflag = 0;
8 int Lflag = 0;
9 
10 static void usage(void);
11 
12 void
13 main(int argc, char *argv[])
14 {
15 	int n, i;
16 	uchar *p, *q;
17 	uchar buf1[BUF], buf2[BUF];
18 	int f1, f2;
19 	vlong nc = 1, o, l = 1;
20 	char *name1, *name2;
21 	uchar *b1s, *b1e, *b2s, *b2e;
22 
23 	ARGBEGIN{
24 	case 's':	sflag = 1; break;
25 	case 'l':	lflag = 1; break;
26 	case 'L':	Lflag = 1; break;
27 	default:	usage();
28 	}ARGEND
29 	if(argc < 2)
30 		usage();
31 	if((f1 = open(name1 = *argv++, OREAD)) == -1){
32 		if(!sflag) perror(name1);
33 		exits("open");
34 	}
35 	if((f2 = open(name2 = *argv++, OREAD)) == -1){
36 		if(!sflag) perror(name2);
37 		exits("open");
38 	}
39 	if(*argv){
40 		o = strtoll(*argv++, 0, 0);
41 		if(seek(f1, o, 0) < 0){
42 			if(!sflag) perror("cmp: seek by offset1");
43 			exits("seek 1");
44 		}
45 	}
46 	if(*argv){
47 		o = strtoll(*argv++, 0, 0);
48 		if(seek(f2, o, 0) < 0){
49 			if(!sflag) perror("cmp: seek by offset2");
50 			exits("seek 2");
51 		}
52 	}
53 	if(*argv)
54 		usage();
55 	b1s = b1e = buf1;
56 	b2s = b2e = buf2;
57 	for(;;){
58 		if(b1s >= b1e){
59 			if(b1s >= &buf1[BUF])
60 				b1s = buf1;
61 			n = read(f1, b1s,  &buf1[BUF] - b1s);
62 			b1e = b1s + n;
63 		}
64 		if(b2s >= b2e){
65 			if(b2s >= &buf2[BUF])
66 				b2s = buf2;
67 			n = read(f2, b2s,  &buf2[BUF] - b2s);
68 			b2e = b2s + n;
69 		}
70 		n = b2e - b2s;
71 		if(n > b1e - b1s)
72 			n = b1e - b1s;
73 		if(n <= 0)
74 			break;
75 		if(memcmp((void *)b1s, (void *)b2s, n) != 0){
76 			if(sflag)
77 				exits("differ");
78 			for(p = b1s, q = b2s, i = 0; i < n; p++, q++, i++) {
79 				if(*p == '\n')
80 					l++;
81 				if(*p != *q){
82 					if(!lflag){
83 						print("%s %s differ: char %lld",
84 						    name1, name2, nc+i);
85 						print(Lflag?" line %lld\n":"\n", l);
86 						exits("differ");
87 					}
88 					print("%6lld 0x%.2x 0x%.2x\n", nc+i, *p, *q);
89 				}
90 			}
91 		}
92 		if(Lflag)
93 			for(p = b1s; p < b1e;)
94 				if(*p++ == '\n')
95 					l++;
96 		nc += n;
97 		b1s += n;
98 		b2s += n;
99 	}
100 	if(b1e - b1s == b2e - b2s)
101 		exits((char *)0);
102 	if(!sflag)
103 		print("EOF on %s\n", (b1e - b1s > b2e - b2s)? name2 : name1);
104 	exits("EOF");
105 }
106 
107 static void
108 usage(void)
109 {
110 	print("Usage: cmp [-lsL] file1 file2 [offset1 [offset2] ]\n");
111 	exits("usage");
112 }