1 b2ad2ef1 2005-01-04 devnull #include <u.h>
 2 b2ad2ef1 2005-01-04 devnull #include <libc.h>
 3 b2ad2ef1 2005-01-04 devnull 
 4 b2ad2ef1 2005-01-04 devnull int	multi;
 5 b2ad2ef1 2005-01-04 devnull int	nlines;
 6 b2ad2ef1 2005-01-04 devnull char	*status = nil;
 7 b2ad2ef1 2005-01-04 devnull 
 8 b2ad2ef1 2005-01-04 devnull int
 9 b2ad2ef1 2005-01-04 devnull line(int fd, char *file)
10 b2ad2ef1 2005-01-04 devnull {
11 b2ad2ef1 2005-01-04 devnull 	char c;
12 b2ad2ef1 2005-01-04 devnull 	int m, n, nalloc;
13 b2ad2ef1 2005-01-04 devnull 	char *buf;
14 b2ad2ef1 2005-01-04 devnull 
15 b2ad2ef1 2005-01-04 devnull 	nalloc = 0;
16 b2ad2ef1 2005-01-04 devnull 	buf = nil;
17 b2ad2ef1 2005-01-04 devnull 	for(m=0; ; ){
18 b2ad2ef1 2005-01-04 devnull 		n = read(fd, &c, 1);
19 b2ad2ef1 2005-01-04 devnull 		if(n < 0){
20 b2ad2ef1 2005-01-04 devnull 			fprint(2, "read: error reading %s: %r\n", file);
21 b2ad2ef1 2005-01-04 devnull 			exits("read error");
22 b2ad2ef1 2005-01-04 devnull 		}
23 b2ad2ef1 2005-01-04 devnull 		if(n == 0){
24 b2ad2ef1 2005-01-04 devnull 			if(m == 0)
25 b2ad2ef1 2005-01-04 devnull 				status = "eof";
26 b2ad2ef1 2005-01-04 devnull 			break;
27 b2ad2ef1 2005-01-04 devnull 		}
28 b2ad2ef1 2005-01-04 devnull 		if(m == nalloc){
29 b2ad2ef1 2005-01-04 devnull 			nalloc += 1024;
30 b2ad2ef1 2005-01-04 devnull 			buf = realloc(buf, nalloc);
31 b2ad2ef1 2005-01-04 devnull 			if(buf == nil){
32 b2ad2ef1 2005-01-04 devnull 				fprint(2, "read: malloc error: %r\n");
33 b2ad2ef1 2005-01-04 devnull 				exits("malloc");
34 b2ad2ef1 2005-01-04 devnull 			}
35 b2ad2ef1 2005-01-04 devnull 		}
36 b2ad2ef1 2005-01-04 devnull 		buf[m++] = c;
37 b2ad2ef1 2005-01-04 devnull 		if(c == '\n')
38 b2ad2ef1 2005-01-04 devnull 			break;
39 b2ad2ef1 2005-01-04 devnull 	}
40 b2ad2ef1 2005-01-04 devnull 	if(m > 0)
41 b2ad2ef1 2005-01-04 devnull 		write(1, buf, m);
42 b2ad2ef1 2005-01-04 devnull 	free(buf);
43 b2ad2ef1 2005-01-04 devnull 	return m;
44 b2ad2ef1 2005-01-04 devnull }
45 b2ad2ef1 2005-01-04 devnull 
46 b2ad2ef1 2005-01-04 devnull void
47 b2ad2ef1 2005-01-04 devnull lines(int fd, char *file)
48 b2ad2ef1 2005-01-04 devnull {
49 b2ad2ef1 2005-01-04 devnull 	do{
50 b2ad2ef1 2005-01-04 devnull 		if(line(fd, file) == 0)
51 b2ad2ef1 2005-01-04 devnull 			break;
52 b2ad2ef1 2005-01-04 devnull 	}while(multi || --nlines>0);
53 b2ad2ef1 2005-01-04 devnull }
54 b2ad2ef1 2005-01-04 devnull 
55 b2ad2ef1 2005-01-04 devnull void
56 b2ad2ef1 2005-01-04 devnull main(int argc, char *argv[])
57 b2ad2ef1 2005-01-04 devnull {
58 b2ad2ef1 2005-01-04 devnull 	int i, fd;
59 b2ad2ef1 2005-01-04 devnull 	char *s;
60 b2ad2ef1 2005-01-04 devnull 
61 b2ad2ef1 2005-01-04 devnull 	ARGBEGIN{
62 b2ad2ef1 2005-01-04 devnull 	case 'm':
63 b2ad2ef1 2005-01-04 devnull 		multi = 1;
64 b2ad2ef1 2005-01-04 devnull 		break;
65 b2ad2ef1 2005-01-04 devnull 	case 'n':
66 b2ad2ef1 2005-01-04 devnull 		s = ARGF();
67 b2ad2ef1 2005-01-04 devnull 		if(s){
68 b2ad2ef1 2005-01-04 devnull 			nlines = atoi(s);
69 b2ad2ef1 2005-01-04 devnull 			break;
70 b2ad2ef1 2005-01-04 devnull 		}
71 b2ad2ef1 2005-01-04 devnull 		/* fall through */
72 b2ad2ef1 2005-01-04 devnull 	default:
73 b2ad2ef1 2005-01-04 devnull 		fprint(2, "usage: read [-m] [-n nlines] [files...]\n");
74 b2ad2ef1 2005-01-04 devnull 		exits("usage");
75 b2ad2ef1 2005-01-04 devnull 	}ARGEND
76 b2ad2ef1 2005-01-04 devnull 
77 b2ad2ef1 2005-01-04 devnull 	if(argc == 0)
78 b2ad2ef1 2005-01-04 devnull 		lines(0, "<stdin>");
79 b2ad2ef1 2005-01-04 devnull 	else
80 b2ad2ef1 2005-01-04 devnull 		for(i=0; i<argc; i++){
81 b2ad2ef1 2005-01-04 devnull 			fd = open(argv[i], OREAD);
82 b2ad2ef1 2005-01-04 devnull 			if(fd < 0){
83 b2ad2ef1 2005-01-04 devnull 				fprint(2, "read: can't open %s: %r\n", argv[i]);
84 b2ad2ef1 2005-01-04 devnull 				exits("open");
85 b2ad2ef1 2005-01-04 devnull 			}
86 b2ad2ef1 2005-01-04 devnull 			lines(fd, argv[i]);
87 b2ad2ef1 2005-01-04 devnull 			close(fd);
88 b2ad2ef1 2005-01-04 devnull 		}
89 b2ad2ef1 2005-01-04 devnull 
90 b2ad2ef1 2005-01-04 devnull 	exits(status);
91 b2ad2ef1 2005-01-04 devnull }