xref: /illumos-gate/usr/src/cmd/line/line.c (revision 4eaa471005973e11a6110b69fe990530b3b95a38)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 /*
33  *	This program reads a single line from the standard input
34  *	and writes it on the standard output. It is probably most useful
35  *	in conjunction with the shell.
36  */
37 
38 #include <limits.h>
39 #include <unistd.h>
40 
41 #define	LSIZE	LINE_MAX		/* POSIX.2 */
42 
43 static char	readc(void);
44 
45 static int EOF;
46 static char nl = '\n';
47 
48 /*ARGSUSED*/
49 int
50 main(int argc, char **argv)
51 {
52 	char c;
53 	char line[LSIZE];
54 	char *linep, *linend;
55 
56 	EOF = 0;
57 	linep = line;
58 	linend = line + LSIZE;
59 
60 	while ((c = readc()) != nl) {
61 		if (linep == linend) {
62 			(void) write(1, line, LSIZE);
63 			linep = line;
64 		}
65 		*linep++ = c;
66 	}
67 
68 	/* LINTED  E_PTRDIFF_T_OVERFLOW */
69 	(void) write(1, line, linep-line);
70 	(void) write(1, &nl, 1);
71 	if (EOF == 1)
72 		return (1);
73 	return (0);
74 }
75 
76 static char
77 readc(void)
78 {
79 	char c;
80 
81 	if (read(0, &c, 1) != 1) {
82 		EOF = 1;
83 		return (nl);
84 	}
85 	else
86 		return (c);
87 }
88