1 bc7cb1a1 2003-11-23 devnull #include <u.h>
  2 bc7cb1a1 2003-11-23 devnull #include <libc.h>
  3 bc7cb1a1 2003-11-23 devnull #include <bio.h>
  4 bc7cb1a1 2003-11-23 devnull 
  5 bc7cb1a1 2003-11-23 devnull #define LB 2048
  6 bc7cb1a1 2003-11-23 devnull int	one;
  7 bc7cb1a1 2003-11-23 devnull int	two;
  8 bc7cb1a1 2003-11-23 devnull int	three;
  9 bc7cb1a1 2003-11-23 devnull 
 10 bc7cb1a1 2003-11-23 devnull char	*ldr[3];
 11 bc7cb1a1 2003-11-23 devnull 
 12 bc7cb1a1 2003-11-23 devnull Biobuf *ib1;
 13 bc7cb1a1 2003-11-23 devnull Biobuf *ib2;
 14 bc7cb1a1 2003-11-23 devnull Biobuf *openfil(char*);
 15 bc7cb1a1 2003-11-23 devnull int	rd(Biobuf*, char*);
 16 bc7cb1a1 2003-11-23 devnull void	wr(char*, int);
 17 bc7cb1a1 2003-11-23 devnull void	copy(Biobuf*, char*, int);
 18 bc7cb1a1 2003-11-23 devnull int	compare(char*, char*);
 19 bc7cb1a1 2003-11-23 devnull 
 20 bc7cb1a1 2003-11-23 devnull void
 21 bc7cb1a1 2003-11-23 devnull main(int argc, char *argv[])
 22 bc7cb1a1 2003-11-23 devnull {
 23 bc7cb1a1 2003-11-23 devnull 	int l;
 24 bc7cb1a1 2003-11-23 devnull 	char	lb1[LB],lb2[LB];
 25 bc7cb1a1 2003-11-23 devnull 
 26 bc7cb1a1 2003-11-23 devnull 	ldr[0] = "";
 27 bc7cb1a1 2003-11-23 devnull 	ldr[1] = "\t";
 28 bc7cb1a1 2003-11-23 devnull 	ldr[2] = "\t\t";
 29 bc7cb1a1 2003-11-23 devnull 	l = 2;
 30 bc7cb1a1 2003-11-23 devnull 	ARGBEGIN{
 31 bc7cb1a1 2003-11-23 devnull 	case '1':
 32 bc7cb1a1 2003-11-23 devnull 		if(!one) {
 33 bc7cb1a1 2003-11-23 devnull 			one = 1;
 34 bc7cb1a1 2003-11-23 devnull 			ldr[1][0] =
 35 bc7cb1a1 2003-11-23 devnull 			ldr[2][l--] = '\0';
 36 bc7cb1a1 2003-11-23 devnull 		}
 37 bc7cb1a1 2003-11-23 devnull 		break;
 38 bc7cb1a1 2003-11-23 devnull 
 39 bc7cb1a1 2003-11-23 devnull 	case '2':
 40 bc7cb1a1 2003-11-23 devnull 		if(!two) {
 41 bc7cb1a1 2003-11-23 devnull 			two = 1;
 42 bc7cb1a1 2003-11-23 devnull 			ldr[2][l--] = '\0';
 43 bc7cb1a1 2003-11-23 devnull 		}
 44 bc7cb1a1 2003-11-23 devnull 		break;
 45 bc7cb1a1 2003-11-23 devnull 
 46 bc7cb1a1 2003-11-23 devnull 	case '3':
 47 bc7cb1a1 2003-11-23 devnull 		three = 1;
 48 bc7cb1a1 2003-11-23 devnull 		break;
 49 bc7cb1a1 2003-11-23 devnull 
 50 bc7cb1a1 2003-11-23 devnull 	default:
 51 bc7cb1a1 2003-11-23 devnull 		goto Usage;
 52 bc7cb1a1 2003-11-23 devnull 
 53 bc7cb1a1 2003-11-23 devnull 	}ARGEND
 54 bc7cb1a1 2003-11-23 devnull 
 55 bc7cb1a1 2003-11-23 devnull 	if(argc < 2) {
 56 bc7cb1a1 2003-11-23 devnull     Usage:
 57 bc7cb1a1 2003-11-23 devnull 		fprint(2, "usage: comm [-123] file1 file2\n");
 58 bc7cb1a1 2003-11-23 devnull 		exits("usage");
 59 bc7cb1a1 2003-11-23 devnull 	}
 60 bc7cb1a1 2003-11-23 devnull 
 61 bc7cb1a1 2003-11-23 devnull 	ib1 = openfil(argv[0]);
 62 bc7cb1a1 2003-11-23 devnull 	ib2 = openfil(argv[1]);
 63 bc7cb1a1 2003-11-23 devnull 
 64 bc7cb1a1 2003-11-23 devnull 
 65 bc7cb1a1 2003-11-23 devnull 	if(rd(ib1,lb1) < 0){
 66 bc7cb1a1 2003-11-23 devnull 		if(rd(ib2,lb2) < 0)
 67 bc7cb1a1 2003-11-23 devnull 			exits(0);
 68 bc7cb1a1 2003-11-23 devnull 		copy(ib2,lb2,2);
 69 bc7cb1a1 2003-11-23 devnull 	}
 70 bc7cb1a1 2003-11-23 devnull 	if(rd(ib2,lb2) < 0)
 71 bc7cb1a1 2003-11-23 devnull 		copy(ib1,lb1,1);
 72 bc7cb1a1 2003-11-23 devnull 
 73 bc7cb1a1 2003-11-23 devnull 	for(;;){
 74 bc7cb1a1 2003-11-23 devnull 		switch(compare(lb1,lb2)) {
 75 bc7cb1a1 2003-11-23 devnull 		case 0:
 76 bc7cb1a1 2003-11-23 devnull 			wr(lb1,3);
 77 bc7cb1a1 2003-11-23 devnull 			if(rd(ib1,lb1) < 0) {
 78 bc7cb1a1 2003-11-23 devnull 				if(rd(ib2,lb2) < 0)
 79 bc7cb1a1 2003-11-23 devnull 					exits(0);
 80 bc7cb1a1 2003-11-23 devnull 				copy(ib2,lb2,2);
 81 bc7cb1a1 2003-11-23 devnull 			}
 82 bc7cb1a1 2003-11-23 devnull 			if(rd(ib2,lb2) < 0)
 83 bc7cb1a1 2003-11-23 devnull 				copy(ib1,lb1,1);
 84 bc7cb1a1 2003-11-23 devnull 			continue;
 85 bc7cb1a1 2003-11-23 devnull 
 86 bc7cb1a1 2003-11-23 devnull 		case 1:
 87 bc7cb1a1 2003-11-23 devnull 			wr(lb1,1);
 88 bc7cb1a1 2003-11-23 devnull 			if(rd(ib1,lb1) < 0)
 89 bc7cb1a1 2003-11-23 devnull 				copy(ib2,lb2,2);
 90 bc7cb1a1 2003-11-23 devnull 			continue;
 91 bc7cb1a1 2003-11-23 devnull 
 92 bc7cb1a1 2003-11-23 devnull 		case 2:
 93 bc7cb1a1 2003-11-23 devnull 			wr(lb2,2);
 94 bc7cb1a1 2003-11-23 devnull 			if(rd(ib2,lb2) < 0)
 95 bc7cb1a1 2003-11-23 devnull 				copy(ib1,lb1,1);
 96 bc7cb1a1 2003-11-23 devnull 			continue;
 97 bc7cb1a1 2003-11-23 devnull 		}
 98 bc7cb1a1 2003-11-23 devnull 	}
 99 bc7cb1a1 2003-11-23 devnull 	exits(0);
100 bc7cb1a1 2003-11-23 devnull }
101 bc7cb1a1 2003-11-23 devnull 
102 bc7cb1a1 2003-11-23 devnull int
103 bc7cb1a1 2003-11-23 devnull rd(Biobuf *file, char *buf)
104 bc7cb1a1 2003-11-23 devnull {
105 bc7cb1a1 2003-11-23 devnull 	int i, c;
106 bc7cb1a1 2003-11-23 devnull 
107 bc7cb1a1 2003-11-23 devnull 	i = 0;
108 bc7cb1a1 2003-11-23 devnull 	while((c = Bgetc(file)) != Beof) {
109 bc7cb1a1 2003-11-23 devnull 		*buf = c;
110 bc7cb1a1 2003-11-23 devnull 		if(c == '\n' || i > LB-2) {
111 bc7cb1a1 2003-11-23 devnull 			*buf = '\0';
112 bc7cb1a1 2003-11-23 devnull 			return 0;
113 bc7cb1a1 2003-11-23 devnull 		}
114 bc7cb1a1 2003-11-23 devnull 		i++;
115 bc7cb1a1 2003-11-23 devnull 		buf++;
116 bc7cb1a1 2003-11-23 devnull 	}
117 bc7cb1a1 2003-11-23 devnull 	return -1;
118 bc7cb1a1 2003-11-23 devnull }
119 bc7cb1a1 2003-11-23 devnull 
120 bc7cb1a1 2003-11-23 devnull void
121 bc7cb1a1 2003-11-23 devnull wr(char *str, int n)
122 bc7cb1a1 2003-11-23 devnull {
123 bc7cb1a1 2003-11-23 devnull 
124 bc7cb1a1 2003-11-23 devnull 	switch(n){
125 bc7cb1a1 2003-11-23 devnull 		case 1:
126 bc7cb1a1 2003-11-23 devnull 			if(one)
127 bc7cb1a1 2003-11-23 devnull 				return;
128 bc7cb1a1 2003-11-23 devnull 			break;
129 bc7cb1a1 2003-11-23 devnull 
130 bc7cb1a1 2003-11-23 devnull 		case 2:
131 bc7cb1a1 2003-11-23 devnull 			if(two)
132 bc7cb1a1 2003-11-23 devnull 				return;
133 bc7cb1a1 2003-11-23 devnull 			break;
134 bc7cb1a1 2003-11-23 devnull 
135 bc7cb1a1 2003-11-23 devnull 		case 3:
136 bc7cb1a1 2003-11-23 devnull 			if(three)
137 bc7cb1a1 2003-11-23 devnull 				return;
138 bc7cb1a1 2003-11-23 devnull 	}
139 bc7cb1a1 2003-11-23 devnull 	print("%s%s\n", ldr[n-1],str);
140 bc7cb1a1 2003-11-23 devnull }
141 bc7cb1a1 2003-11-23 devnull 
142 bc7cb1a1 2003-11-23 devnull void
143 bc7cb1a1 2003-11-23 devnull copy(Biobuf *ibuf, char *lbuf, int n)
144 bc7cb1a1 2003-11-23 devnull {
145 bc7cb1a1 2003-11-23 devnull 	do
146 bc7cb1a1 2003-11-23 devnull 		wr(lbuf,n);
147 bc7cb1a1 2003-11-23 devnull 	while(rd(ibuf,lbuf) >= 0);
148 bc7cb1a1 2003-11-23 devnull 	exits(0);
149 bc7cb1a1 2003-11-23 devnull }
150 bc7cb1a1 2003-11-23 devnull 
151 bc7cb1a1 2003-11-23 devnull int
152 bc7cb1a1 2003-11-23 devnull compare(char *a, char *b)
153 bc7cb1a1 2003-11-23 devnull {
154 bc7cb1a1 2003-11-23 devnull 	while(*a == *b){
155 bc7cb1a1 2003-11-23 devnull 		if(*a == '\0')
156 bc7cb1a1 2003-11-23 devnull 			return 0;
157 bc7cb1a1 2003-11-23 devnull 		a++;
158 bc7cb1a1 2003-11-23 devnull 		b++;
159 bc7cb1a1 2003-11-23 devnull 	}
160 bc7cb1a1 2003-11-23 devnull 	if(*a < *b)
161 bc7cb1a1 2003-11-23 devnull 		return 1;
162 bc7cb1a1 2003-11-23 devnull 	return 2;
163 bc7cb1a1 2003-11-23 devnull }
164 bc7cb1a1 2003-11-23 devnull 
165 bc7cb1a1 2003-11-23 devnull Biobuf*
166 bc7cb1a1 2003-11-23 devnull openfil(char *s)
167 bc7cb1a1 2003-11-23 devnull {
168 bc7cb1a1 2003-11-23 devnull 	Biobuf *b;
169 bc7cb1a1 2003-11-23 devnull 
170 bc7cb1a1 2003-11-23 devnull 	if(s[0]=='-' && s[1]==0)
171 bc7cb1a1 2003-11-23 devnull 		s = "/fd/0";
172 bc7cb1a1 2003-11-23 devnull 	b = Bopen(s, OREAD);
173 bc7cb1a1 2003-11-23 devnull 	if(b)
174 bc7cb1a1 2003-11-23 devnull 		return b;
175 bc7cb1a1 2003-11-23 devnull 	fprint(2,"comm: cannot open %s: %r\n",s);
176 bc7cb1a1 2003-11-23 devnull 	exits("open");
177 bc7cb1a1 2003-11-23 devnull 	return 0;	/* shut up ken */
178 bc7cb1a1 2003-11-23 devnull }