xref: /illumos-gate/usr/src/lib/libxcurses/src/libc/mks/m_pathca.c (revision 3ce5372277f4657ad0e52d36c979527c4ca22de2)
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 (c) 1996, by Sun Microsystems, Inc.
24  * All rights reserved.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*
30  * m_pathcat: mks specific library routine.
31  *
32  * Copyright 1992 by Mortice Kern Systems Inc.  All rights reserved.
33  *
34  */
35 
36 #ifdef M_RCSID
37 #ifndef lint
38 static char rcsID[] = "$Header: /rd/src/libc/mks/rcs/m_pathca.c 1.11 1995/04/12 14:14:19 miked Exp $";
39 #endif
40 #endif
41 
42 #include <mks.h>
43 #include <errno.h>
44 #include <limits.h>
45 #include <stdlib.h>
46 #include <string.h>
47 
48 /*f
49  * Concatenate a directory and filename, inserting / if necessary.
50  * Return dynamically allocated pointer to result string.
51  * On error: return NULL and set errno.
52  *
53  * Errors can occur if:
54  *    dir == NULL
55  *    file == NULL
56  *    dir is an invalid pathname
57  *    strlen(dir) + strlen(file) +2 > maximum allowable pathlength
58  *
59  * note: if PATH_MAX has to be retrieved by m_pathmax(dir),
60  * we may return error if the dir name has problems,
61  * which the caller had best expect.
62  */
63 char *
64 m_pathcat(dir, file)
65 const char *dir;
66 const char *file;
67 {
68 	char *dest;
69 	int dir_len;
70 	int file_len;
71 	int m;
72 	int l;
73 
74 	if ((dir == NULL) || (file == NULL))
75 		goto err;
76 
77 #ifdef	PATH_MAX
78 	l = PATH_MAX;
79 #else
80 	l = m_pathmax(dir);
81 	if (l < 0)
82 		return (NULL);	/* Errno is set by m_pathmax() */
83 #endif
84 
85 	dir_len = strlen(dir);
86 	/*
87 	 * add one for seperator eg. '/'
88 	 */
89 	m = dir_len+1;
90 
91 	file_len = strlen(file);
92 	if (file_len > 0) {
93 		/*
94 		 * add one null termination char
95 		 */
96 		m += file_len+1;
97 	}
98 
99 	if (m > l) {
100 err:
101 #ifdef	ENAMETOOLONG
102 		errno = ENAMETOOLONG;
103 #else
104 		/*
105 		 * we need to return an errno. So pick EINVAL.
106 		 * This should be common on all systems.
107 		 */
108 		errno = EINVAL;
109 #endif
110 		return (NULL);
111 	}
112 
113 	/*
114 	 * use m_malloc() - this guarantees a valid errno return on error
115 	 */
116 	if ((dest = m_malloc(m)) == NULL) {
117 		return (NULL);
118 	}
119 
120 	strcpy(dest, dir);
121 	if (file_len > 0) {
122 		if (dir_len > 0
123 		    && !M_FSDELIM(dest[dir_len-1])
124 		    && !M_DRDELIM(dest[dir_len-1])) {
125 			dest[dir_len++] = '/';
126 		}
127 		strcpy(dest+dir_len, file);
128 	}
129 	return (dest);
130 }
131