1/* $NetBSD: fparseln.c,v 1.9 1999/09/20 04:48:06 lukem Exp $ */
2
3/*
4 * Copyright (c) 1997 Christos Zoulas. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed by Christos Zoulas.
17 * 4. The name of the author may not be used to endorse or promote products
18 * derived from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33__FBSDID("$FreeBSD: head/lib/libutil/fparseln.c 121193 2003-10-18 10:04:16Z markm $");
34
35#include <sys/types.h>
36#include <assert.h>
37#include <errno.h>
38#include <stdio.h>
39#include <string.h>
40#include <stdlib.h>
41#include <libutil.h>
42
43static int isescaped(const char *, const char *, int);
44
45/* isescaped():
46 * Return true if the character in *p that belongs to a string
47 * that starts in *sp, is escaped by the escape character esc.
48 */
49static int
50isescaped(const char *sp, const char *p, int esc)
51{
52 const char *cp;
53 size_t ne;
54
55#if 0
56 _DIAGASSERT(sp != NULL);
57 _DIAGASSERT(p != NULL);
58#endif
59
60 /* No escape character */
61 if (esc == '\0')
62 return 1;
63
64 /* Count the number of escape characters that precede ours */
65 for (ne = 0, cp = p; --cp >= sp && *cp == esc; ne++)
66 continue;
67
68 /* Return true if odd number of escape characters */
69 return (ne & 1) != 0;
70}
71
72
73/* fparseln():
74 * Read a line from a file parsing continuations ending in \
75 * and eliminating trailing newlines, or comments starting with
76 * the comment char.
77 */
78char *
79fparseln(FILE *fp, size_t *size, size_t *lineno, const char str[3], int flags)
80{
81 static const char dstr[3] = { '\\', '\\', '#' };
82
83 size_t s, len;
84 char *buf;
85 char *ptr, *cp;
86 int cnt;
87 char esc, con, nl, com;
88
89#if 0
90 _DIAGASSERT(fp != NULL);
91#endif
92
93 len = 0;
94 buf = NULL;
95 cnt = 1;
96
97 if (str == NULL)
98 str = dstr;
99
100 esc = str[0];
101 con = str[1];
102 com = str[2];
103 /*
104 * XXX: it would be cool to be able to specify the newline character,
105 * but unfortunately, fgetln does not let us
106 */
107 nl = '\n';
108
109 while (cnt) {
110 cnt = 0;
111
112 if (lineno)
113 (*lineno)++;
114
115 if ((ptr = fgetln(fp, &s)) == NULL)
116 break;
117
118 if (s && com) { /* Check and eliminate comments */
119 for (cp = ptr; cp < ptr + s; cp++)
120 if (*cp == com && !isescaped(ptr, cp, esc)) {
121 s = cp - ptr;
122 cnt = s == 0 && buf == NULL;
123 break;
124 }
125 }
126
127 if (s && nl) { /* Check and eliminate newlines */
128 cp = &ptr[s - 1];
129
130 if (*cp == nl)
131 s--; /* forget newline */
132 }
133
134 if (s && con) { /* Check and eliminate continuations */
135 cp = &ptr[s - 1];
136
137 if (*cp == con && !isescaped(ptr, cp, esc)) {
138 s--; /* forget escape */
139 cnt = 1;
140 }
141 }
142
143 if (s == 0 && buf != NULL)
144 continue;
145
146 if ((cp = realloc(buf, len + s + 1)) == NULL) {
147 free(buf);
148 return NULL;
149 }
150 buf = cp;
151
152 (void) memcpy(buf + len, ptr, s);
153 len += s;
154 buf[len] = '\0';
155 }
156
157 if ((flags & FPARSELN_UNESCALL) != 0 && esc && buf != NULL &&
158 strchr(buf, esc) != NULL) {
159 ptr = cp = buf;
160 while (cp[0] != '\0') {
161 int skipesc;
162
163 while (cp[0] != '\0' && cp[0] != esc)
164 *ptr++ = *cp++;
165 if (cp[0] == '\0' || cp[1] == '\0')
166 break;
167
168 skipesc = 0;
169 if (cp[1] == com)
170 skipesc += (flags & FPARSELN_UNESCCOMM);
171 if (cp[1] == con)
172 skipesc += (flags & FPARSELN_UNESCCONT);
173 if (cp[1] == esc)
174 skipesc += (flags & FPARSELN_UNESCESC);
175 if (cp[1] != com && cp[1] != con && cp[1] != esc)
176 skipesc = (flags & FPARSELN_UNESCREST);
177
178 if (skipesc)
179 cp++;
180 else
181 *ptr++ = *cp++;
182 *ptr++ = *cp++;
183 }
184 *ptr = '\0';
185 len = strlen(buf);
186 }
187
188 if (size)
189 *size = len;
190 return buf;
191}
192
193#ifdef TEST
194
195int
196main(int argc, char *argv[])
197{
198 char *ptr;
199 size_t size, line;
200
201 line = 0;
202 while ((ptr = fparseln(stdin, &size, &line, NULL,
203 FPARSELN_UNESCALL)) != NULL)
204 printf("line %d (%d) |%s|\n", line, size, ptr);
205 return 0;
206}
207
208/*
209
210# This is a test
211line 1
212line 2 \
213line 3 # Comment
214line 4 \# Not comment \\\\
215
216# And a comment \
217line 5 \\\
218line 6
219
220*/
221
222#endif /* TEST */
2
3/*
4 * Copyright (c) 1997 Christos Zoulas. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed by Christos Zoulas.
17 * 4. The name of the author may not be used to endorse or promote products
18 * derived from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33__FBSDID("$FreeBSD: head/lib/libutil/fparseln.c 121193 2003-10-18 10:04:16Z markm $");
34
35#include <sys/types.h>
36#include <assert.h>
37#include <errno.h>
38#include <stdio.h>
39#include <string.h>
40#include <stdlib.h>
41#include <libutil.h>
42
43static int isescaped(const char *, const char *, int);
44
45/* isescaped():
46 * Return true if the character in *p that belongs to a string
47 * that starts in *sp, is escaped by the escape character esc.
48 */
49static int
50isescaped(const char *sp, const char *p, int esc)
51{
52 const char *cp;
53 size_t ne;
54
55#if 0
56 _DIAGASSERT(sp != NULL);
57 _DIAGASSERT(p != NULL);
58#endif
59
60 /* No escape character */
61 if (esc == '\0')
62 return 1;
63
64 /* Count the number of escape characters that precede ours */
65 for (ne = 0, cp = p; --cp >= sp && *cp == esc; ne++)
66 continue;
67
68 /* Return true if odd number of escape characters */
69 return (ne & 1) != 0;
70}
71
72
73/* fparseln():
74 * Read a line from a file parsing continuations ending in \
75 * and eliminating trailing newlines, or comments starting with
76 * the comment char.
77 */
78char *
79fparseln(FILE *fp, size_t *size, size_t *lineno, const char str[3], int flags)
80{
81 static const char dstr[3] = { '\\', '\\', '#' };
82
83 size_t s, len;
84 char *buf;
85 char *ptr, *cp;
86 int cnt;
87 char esc, con, nl, com;
88
89#if 0
90 _DIAGASSERT(fp != NULL);
91#endif
92
93 len = 0;
94 buf = NULL;
95 cnt = 1;
96
97 if (str == NULL)
98 str = dstr;
99
100 esc = str[0];
101 con = str[1];
102 com = str[2];
103 /*
104 * XXX: it would be cool to be able to specify the newline character,
105 * but unfortunately, fgetln does not let us
106 */
107 nl = '\n';
108
109 while (cnt) {
110 cnt = 0;
111
112 if (lineno)
113 (*lineno)++;
114
115 if ((ptr = fgetln(fp, &s)) == NULL)
116 break;
117
118 if (s && com) { /* Check and eliminate comments */
119 for (cp = ptr; cp < ptr + s; cp++)
120 if (*cp == com && !isescaped(ptr, cp, esc)) {
121 s = cp - ptr;
122 cnt = s == 0 && buf == NULL;
123 break;
124 }
125 }
126
127 if (s && nl) { /* Check and eliminate newlines */
128 cp = &ptr[s - 1];
129
130 if (*cp == nl)
131 s--; /* forget newline */
132 }
133
134 if (s && con) { /* Check and eliminate continuations */
135 cp = &ptr[s - 1];
136
137 if (*cp == con && !isescaped(ptr, cp, esc)) {
138 s--; /* forget escape */
139 cnt = 1;
140 }
141 }
142
143 if (s == 0 && buf != NULL)
144 continue;
145
146 if ((cp = realloc(buf, len + s + 1)) == NULL) {
147 free(buf);
148 return NULL;
149 }
150 buf = cp;
151
152 (void) memcpy(buf + len, ptr, s);
153 len += s;
154 buf[len] = '\0';
155 }
156
157 if ((flags & FPARSELN_UNESCALL) != 0 && esc && buf != NULL &&
158 strchr(buf, esc) != NULL) {
159 ptr = cp = buf;
160 while (cp[0] != '\0') {
161 int skipesc;
162
163 while (cp[0] != '\0' && cp[0] != esc)
164 *ptr++ = *cp++;
165 if (cp[0] == '\0' || cp[1] == '\0')
166 break;
167
168 skipesc = 0;
169 if (cp[1] == com)
170 skipesc += (flags & FPARSELN_UNESCCOMM);
171 if (cp[1] == con)
172 skipesc += (flags & FPARSELN_UNESCCONT);
173 if (cp[1] == esc)
174 skipesc += (flags & FPARSELN_UNESCESC);
175 if (cp[1] != com && cp[1] != con && cp[1] != esc)
176 skipesc = (flags & FPARSELN_UNESCREST);
177
178 if (skipesc)
179 cp++;
180 else
181 *ptr++ = *cp++;
182 *ptr++ = *cp++;
183 }
184 *ptr = '\0';
185 len = strlen(buf);
186 }
187
188 if (size)
189 *size = len;
190 return buf;
191}
192
193#ifdef TEST
194
195int
196main(int argc, char *argv[])
197{
198 char *ptr;
199 size_t size, line;
200
201 line = 0;
202 while ((ptr = fparseln(stdin, &size, &line, NULL,
203 FPARSELN_UNESCALL)) != NULL)
204 printf("line %d (%d) |%s|\n", line, size, ptr);
205 return 0;
206}
207
208/*
209
210# This is a test
211line 1
212line 2 \
213line 3 # Comment
214line 4 \# Not comment \\\\
215
216# And a comment \
217line 5 \\\
218line 6
219
220*/
221
222#endif /* TEST */