1 /*------------------------------------------------------------------
2 * strremovews_s.c
3 *
4 * November 2008, Bo Berry
5 *
6 * Copyright (c) 2008-2011 by Cisco Systems, Inc
7 * All rights resevered.
8 *
9 * Permission is hereby granted, free of charge, to any person
10 * obtaining a copy of this software and associated documentation
11 * files (the "Software"), to deal in the Software without
12 * restriction, including without limitation the rights to use,
13 * copy, modify, merge, publish, distribute, sublicense, and/or
14 * sell copies of the Software, and to permit persons to whom the
15 * Software is furnished to do so, subject to the following
16 * conditions:
17 *
18 * The above copyright notice and this permission notice shall be
19 * included in all copies or substantial portions of the Software.
20 *
21 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
22 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
23 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
24 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
25 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
26 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
27 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
28 * OTHER DEALINGS IN THE SOFTWARE.
29 *------------------------------------------------------------------
30 */
31
32 #include "safeclib_private.h"
33 #include "safe_str_constraint.h"
34 #include "safe_str_lib.h"
35
36
37 /**
38 * NAME
39 * strremovews_s
40 *
41 * SYNOPSIS
42 * #include "safe_str_lib.h"
43 * errno_t
44 * strremovews_s(char *dest, rsize_t dmax)
45 *
46 * DESCRIPTION
47 * Removes beginning and trailing whitespace from the string pointed to by
48 * dest by shifting the text left over writting the beginning whitespace.
49 * The shifted-trimmed text is null terminated.
50 *
51 * The text is shifted so the original pointer can continue to be used. This
52 * is useful when the memory was malloc'ed and will need to be freed.
53 *
54 * EXTENSION TO
55 * ISO/IEC TR 24731, Programming languages, environments
56 * and system software interfaces, Extensions to the C Library,
57 * Part I: Bounds-checking interfaces
58 *
59 * INPUT PARAMETERS
60 * dest pointer to string to remove whitespace
61 *
62 * dmax restricted maximum length of string
63 *
64 * RUNTIME CONSTRAINTS
65 * dest shall not be a null pointer.
66 * dmax shall not be 0
67 * dmax shall not be greater than RSIZE_MAX_STR
68 * dest shall be null terminated
69 *
70 * RETURN VALUE
71 * EOK
72 * ESNULLP NULL pointer
73 * ESZEROL zero length
74 * ESLEMAX length exceeds max limit
75 * ESUNTERM dest was not null terminated
76 *
77 * SEE ALSO
78 * strljustify_s(),
79 *
80 */
81 errno_t
strremovews_s(char * dest,rsize_t dmax)82 strremovews_s (char *dest, rsize_t dmax)
83 {
84 char *orig_dest;
85 char *orig_end;
86 rsize_t orig_dmax;
87
88 if (dest == NULL) {
89 invoke_safe_str_constraint_handler("strremovews_s: dest is null",
90 NULL, ESNULLP);
91 return (ESNULLP);
92 }
93
94 if (dmax == 0 ) {
95 invoke_safe_str_constraint_handler("strremovews_s: dmax is 0",
96 NULL, ESZEROL);
97 return (ESZEROL);
98 }
99
100 if (dmax > RSIZE_MAX_STR) {
101 invoke_safe_str_constraint_handler("strremovews_s: dmax exceeds max",
102 NULL, ESLEMAX);
103 return (ESLEMAX);
104 }
105
106 /*
107 * corner case, a dmax of one requires a null
108 */
109 if (*dest == '\0' || dmax <= RSIZE_MIN_STR) {
110 *dest = '\0';
111 return (EOK);
112 }
113
114 orig_dest = dest;
115 orig_dmax = dmax;
116
117 /*
118 * scan the string to be sure it is properly terminated
119 */
120 while (*dest) {
121 if (dmax == 0) {
122 while (orig_dmax) { *orig_dest++ = '\0'; orig_dmax--; }
123
124 invoke_safe_str_constraint_handler(
125 "strremovews_s: dest is unterminated",
126 NULL, ESUNTERM);
127 return (ESUNTERM);
128 }
129 dmax--;
130 dest++;
131 }
132
133 /*
134 * find first non-white space char
135 */
136 orig_end = dest-1;
137 dest = orig_dest;
138 while ((*dest == ' ') || (*dest == '\t')) {
139 dest++;
140 }
141
142 /*
143 * shift the text over the leading spaces
144 */
145 if (orig_dest != dest && *dest) {
146 while (*dest) {
147 *orig_dest++ = *dest;
148 *dest++ = ' ';
149 }
150 *dest = '\0';
151 }
152
153 /*
154 * strip trailing whitespace
155 */
156 dest = orig_end;
157 while ((*dest == ' ') || (*dest == '\t')) {
158 *dest = '\0';
159 dest--;
160 }
161
162 return (EOK);
163 }
164 EXPORT_SYMBOL(strremovews_s)
165