/[groff]/groff/src/libs/libgroff/quotearg.c
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Contents of /groff/src/libs/libgroff/quotearg.c

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Revision 1.4 - (show annotations) (download)
Thu May 26 21:02:00 2005 UTC (18 years, 10 months ago) by wl
Branch: MAIN
CVS Tags: groff-1_19_2
Changes since 1.3: +1 -1 lines
File MIME type: text/plain

* All affected files: Update postal address of FSF.

1 /* Copyright (C) 2004
2 Free Software Foundation, Inc.
3 Written by: Jeff Conrad (jeff_conrad@msn.com)
4 and Keith Marshall (keith.d.marshall@ntlworld.com)
5
6 This file is part of groff.
7
8 groff is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 2, or (at your option) any later
11 version.
12
13 groff is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
17
18 You should have received a copy of the GNU General Public License along
19 with groff; see the file COPYING. If not, write to the Free Software
20 Foundation, 51 Franklin St - Fifth Floor, Boston, MA 02110-1301, USA. */
21
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <ctype.h>
26 #include <limits.h>
27
28 /* Define the default mechanism, and messages, for error reporting
29 * (user may substitute a preferred alternative, by defining his own
30 * implementation of the macros REPORT_ERROR, QUOTE_ARG_MALLOC_FAILED
31 * and QUOTE_ARG_REALLOC_FAILED, in the header file `nonposix.h').
32 */
33
34 #include "nonposix.h"
35
36 #ifndef REPORT_ERROR
37 # define REPORT_ERROR(WHY) fprintf(stderr, "%s:%s\n", program_name, WHY)
38 #endif
39 #ifndef QUOTE_ARG_MALLOC_ERROR
40 # define QUOTE_ARG_MALLOC_ERROR "malloc: Buffer allocation failed"
41 #endif
42 #ifndef QUOTE_ARG_REALLOC_ERROR
43 # define QUOTE_ARG_REALLOC_ERROR "realloc: Buffer resize failed"
44 #endif
45
46 extern char *program_name; /* main program must define this */
47
48 #undef FALSE
49 #undef TRUE
50 #define FALSE 0
51 #define TRUE 1
52
53 static int
54 needs_quoting(const char *string)
55 {
56 /* Scan `string' to see whether it needs quoting for MSVC `spawn'/`exec'
57 * (i.e., whether it contains whitespace or embedded quotes).
58 */
59
60 if (string == NULL) /* ignore NULL strings */
61 return FALSE;
62
63 if (*string == '\0') /* explicit arguments of zero length */
64 return TRUE; /* need quoting, so they aren't discarded */
65
66 while (*string) {
67 /* Scan non-NULL strings, up to '\0' terminator,
68 * returning 'TRUE' if quote or white space found.
69 */
70
71 if (*string == '"' || isspace(*string))
72 return TRUE;
73
74 /* otherwise, continue scanning to end of string */
75
76 ++string;
77 }
78
79 /* Fall through, if no quotes or white space found,
80 * in which case, return `FALSE'.
81 */
82
83 return FALSE;
84 }
85
86 char *
87 quote_arg(char *string)
88 {
89 /* Enclose arguments in double quotes so that the parsing done in the
90 * MSVC runtime startup code doesn't split them at whitespace. Escape
91 * embedded double quotes so that they emerge intact from the parsing.
92 */
93
94 int backslashes;
95 char *quoted, *p, *q;
96
97 if (needs_quoting(string)) {
98 /* Need to create a quoted copy of `string';
99 * maximum buffer space needed is twice the original length,
100 * plus two enclosing quotes and one `\0' terminator.
101 */
102
103 if ((quoted = (char *)malloc(2 * strlen(string) + 3)) == NULL) {
104 /* Couldn't get a buffer for the quoted string,
105 * so complain, and bail out gracefully.
106 */
107
108 REPORT_ERROR(QUOTE_ARG_MALLOC_ERROR);
109 exit(1);
110 }
111
112 /* Ok to proceed:
113 * insert the opening quote, then copy the source string,
114 * adding escapes as required.
115 */
116
117 *quoted = '"';
118 for (backslashes = 0, p = string, q = quoted; *p; p++) {
119 if (*p == '\\') {
120 /* Just count backslashes when we find them.
121 * We will copy them out later, when we know if the count
122 * needs to be adjusted, to escape an embedded quote.
123 */
124
125 ++backslashes;
126 }
127 else if (*p == '"') {
128 /* This embedded quote character must be escaped,
129 * but first double up any immediately preceding backslashes,
130 * with one extra, as the escape character.
131 */
132
133 for (backslashes += backslashes + 1; backslashes; backslashes--)
134 *++q = '\\';
135
136 /* and now, add the quote character itself */
137
138 *++q = '"';
139 }
140 else {
141 /* Any other character is simply copied,
142 * but first, if we have any pending backslashes,
143 * we must now insert them, without any count adjustment.
144 */
145
146 while (backslashes) {
147 *++q = '\\';
148 --backslashes;
149 }
150
151 /* and then, copy the current character */
152
153 *++q = *p;
154 }
155 }
156
157 /* At end of argument:
158 * If any backslashes remain to be copied out, append them now,
159 * doubling the actual count to protect against reduction by MSVC,
160 * as a consequence of the immediately following closing quote.
161 */
162
163 for (backslashes += backslashes; backslashes; backslashes--)
164 *++q = '\\';
165
166 /* Finally,
167 * add the closing quote, terminate the quoted string,
168 * and adjust its size to what was actually required,
169 * ready for return.
170 */
171
172 *++q = '"';
173 *++q = '\0';
174 if ((string = (char *)realloc(quoted, strlen(quoted) + 1)) == NULL) {
175 /* but bail out gracefully, on error */
176
177 REPORT_ERROR(QUOTE_ARG_REALLOC_ERROR);
178 exit(1);
179 }
180 }
181
182 /* `string' now refers to the argument,
183 * quoted and escaped, as required.
184 */
185
186 return string;
187 }
188
189 void
190 purge_quoted_args(char **argv)
191 {
192 /* To avoid memory leaks,
193 * free all memory previously allocated by `quoted_arg()',
194 * within the scope of the referring argument vector, `argv'.
195 */
196
197 if (argv)
198 while (*argv) {
199 /* Any argument beginning with a double quote
200 * SHOULD have been allocated by `quoted_arg()'.
201 */
202
203 if (**argv == '"')
204 free( *argv ); /* so free its allocation */
205 ++argv; /* and continue to the next argument */
206 }
207 }
208
209 /* quotearg.c: end of file */

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