xref: /illumos-gate/usr/src/cmd/line/line.c (revision 2a8bcb4e)
1*7c478bd9Sstevel@tonic-gate /*
2*7c478bd9Sstevel@tonic-gate  * CDDL HEADER START
3*7c478bd9Sstevel@tonic-gate  *
4*7c478bd9Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*7c478bd9Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*7c478bd9Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*7c478bd9Sstevel@tonic-gate  * with the License.
8*7c478bd9Sstevel@tonic-gate  *
9*7c478bd9Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*7c478bd9Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*7c478bd9Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*7c478bd9Sstevel@tonic-gate  * and limitations under the License.
13*7c478bd9Sstevel@tonic-gate  *
14*7c478bd9Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*7c478bd9Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*7c478bd9Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*7c478bd9Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*7c478bd9Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*7c478bd9Sstevel@tonic-gate  *
20*7c478bd9Sstevel@tonic-gate  * CDDL HEADER END
21*7c478bd9Sstevel@tonic-gate  */
22*7c478bd9Sstevel@tonic-gate /*
23*7c478bd9Sstevel@tonic-gate  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24*7c478bd9Sstevel@tonic-gate  * Use is subject to license terms.
25*7c478bd9Sstevel@tonic-gate  */
26*7c478bd9Sstevel@tonic-gate 
27*7c478bd9Sstevel@tonic-gate /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28*7c478bd9Sstevel@tonic-gate /*	  All Rights Reserved  	*/
29*7c478bd9Sstevel@tonic-gate 
30*7c478bd9Sstevel@tonic-gate /*
31*7c478bd9Sstevel@tonic-gate  *	This program reads a single line from the standard input
32*7c478bd9Sstevel@tonic-gate  *	and writes it on the standard output. It is probably most useful
33*7c478bd9Sstevel@tonic-gate  *	in conjunction with the shell.
34*7c478bd9Sstevel@tonic-gate  */
35*7c478bd9Sstevel@tonic-gate 
36*7c478bd9Sstevel@tonic-gate #include <limits.h>
37*7c478bd9Sstevel@tonic-gate #include <unistd.h>
38*7c478bd9Sstevel@tonic-gate 
39*7c478bd9Sstevel@tonic-gate #define	LSIZE	LINE_MAX		/* POSIX.2 */
40*7c478bd9Sstevel@tonic-gate 
41*7c478bd9Sstevel@tonic-gate static char	readc(void);
42*7c478bd9Sstevel@tonic-gate 
43*7c478bd9Sstevel@tonic-gate static int EOF;
44*7c478bd9Sstevel@tonic-gate static char nl = '\n';
45*7c478bd9Sstevel@tonic-gate 
46*7c478bd9Sstevel@tonic-gate /*ARGSUSED*/
47*7c478bd9Sstevel@tonic-gate int
main(int argc,char ** argv)48*7c478bd9Sstevel@tonic-gate main(int argc, char **argv)
49*7c478bd9Sstevel@tonic-gate {
50*7c478bd9Sstevel@tonic-gate 	char c;
51*7c478bd9Sstevel@tonic-gate 	char line[LSIZE];
52*7c478bd9Sstevel@tonic-gate 	char *linep, *linend;
53*7c478bd9Sstevel@tonic-gate 
54*7c478bd9Sstevel@tonic-gate 	EOF = 0;
55*7c478bd9Sstevel@tonic-gate 	linep = line;
56*7c478bd9Sstevel@tonic-gate 	linend = line + LSIZE;
57*7c478bd9Sstevel@tonic-gate 
58*7c478bd9Sstevel@tonic-gate 	while ((c = readc()) != nl) {
59*7c478bd9Sstevel@tonic-gate 		if (linep == linend) {
60*7c478bd9Sstevel@tonic-gate 			(void) write(1, line, LSIZE);
61*7c478bd9Sstevel@tonic-gate 			linep = line;
62*7c478bd9Sstevel@tonic-gate 		}
63*7c478bd9Sstevel@tonic-gate 		*linep++ = c;
64*7c478bd9Sstevel@tonic-gate 	}
65*7c478bd9Sstevel@tonic-gate 
66*7c478bd9Sstevel@tonic-gate 	/* LINTED  E_PTRDIFF_T_OVERFLOW */
67*7c478bd9Sstevel@tonic-gate 	(void) write(1, line, linep-line);
68*7c478bd9Sstevel@tonic-gate 	(void) write(1, &nl, 1);
69*7c478bd9Sstevel@tonic-gate 	if (EOF == 1)
70*7c478bd9Sstevel@tonic-gate 		return (1);
71*7c478bd9Sstevel@tonic-gate 	return (0);
72*7c478bd9Sstevel@tonic-gate }
73*7c478bd9Sstevel@tonic-gate 
74*7c478bd9Sstevel@tonic-gate static char
readc(void)75*7c478bd9Sstevel@tonic-gate readc(void)
76*7c478bd9Sstevel@tonic-gate {
77*7c478bd9Sstevel@tonic-gate 	char c;
78*7c478bd9Sstevel@tonic-gate 
79*7c478bd9Sstevel@tonic-gate 	if (read(0, &c, 1) != 1) {
80*7c478bd9Sstevel@tonic-gate 		EOF = 1;
81*7c478bd9Sstevel@tonic-gate 		return (nl);
82*7c478bd9Sstevel@tonic-gate 	}
83*7c478bd9Sstevel@tonic-gate 	else
84*7c478bd9Sstevel@tonic-gate 		return (c);
85*7c478bd9Sstevel@tonic-gate }
86