summaryrefslogtreecommitdiffstats
path: root/src/common/util-common.c
blob: 7d43ac0dc9b383835a01b25a01fad19e341aed7d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
/*
 *  util-common.c
 *
 *  Copyright (c) 2006-2020 Pacman Development Team <pacman-dev@archlinux.org>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <ctype.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>

#include "util-common.h"


/** Parse the basename of a program from a path.
* @param path path to parse basename from
*
* @return everything following the final '/'
*/
const char *mbasename(const char *path)
{
	const char *last = strrchr(path, '/');
	if(last) {
		return last + 1;
	}
	return path;
}

/** Parse the dirname of a program from a path.
* The path returned should be freed.
* @param path path to parse dirname from
*
* @return everything preceding the final '/'
*/
char *mdirname(const char *path)
{
	char *ret, *last;

	/* null or empty path */
	if(path == NULL || *path == '\0') {
		return strdup(".");
	}

	if((ret = strdup(path)) == NULL) {
		return NULL;
	}

	last = strrchr(ret, '/');

	if(last != NULL) {
		/* we found a '/', so terminate our string */
		if(last == ret) {
			/* return "/" for root */
			last++;
		}
		*last = '\0';
		return ret;
	}

	/* no slash found */
	free(ret);
	return strdup(".");
}

/** lstat wrapper that treats /path/dirsymlink/ the same as /path/dirsymlink.
 * Linux lstat follows POSIX semantics and still performs a dereference on
 * the first, and for uses of lstat in libalpm this is not what we want.
 * @param path path to file to lstat
 * @param buf structure to fill with stat information
 * @return the return code from lstat
 */
int llstat(char *path, struct stat *buf)
{
	int ret;
	char *c = NULL;
	size_t len = strlen(path);

	while(len > 1 && path[len - 1] == '/') {
		--len;
		c = path + len;
	}

	if(c) {
		*c = '\0';
		ret = lstat(path, buf);
		*c = '/';
	} else {
		ret = lstat(path, buf);
	}

	return ret;
}

/** Wrapper around fgets() which properly handles EINTR
 * @param s string to read into
 * @param size maximum length to read
 * @param stream stream to read from
 * @return value returned by fgets()
 */
char *safe_fgets(char *s, int size, FILE *stream)
{
	char *ret;
	int errno_save = errno, ferror_save = ferror(stream);
	while((ret = fgets(s, size, stream)) == NULL && !feof(stream)) {
		if(errno == EINTR) {
			/* clear any errors we set and try again */
			errno = errno_save;
			if(!ferror_save) {
				clearerr(stream);
			}
		} else {
			break;
		}
	}
	return ret;
}

/* Trim whitespace and newlines from a string
 */
size_t strtrim(char *str)
{
	char *end, *pch = str;

	if(str == NULL || *str == '\0') {
		/* string is empty, so we're done. */
		return 0;
	}

	while(isspace((unsigned char)*pch)) {
		pch++;
	}
	if(pch != str) {
		size_t len = strlen(pch);
		/* check if there wasn't anything but whitespace in the string. */
		if(len == 0) {
			*str = '\0';
			return 0;
		}
		memmove(str, pch, len + 1);
		pch = str;
	}

	end = (str + strlen(str) - 1);
	while(isspace((unsigned char)*end)) {
		end--;
	}
	*++end = '\0';

	return end - pch;
}

#ifndef HAVE_STRNLEN
/* A quick and dirty implementation derived from glibc */
/** Determines the length of a fixed-size string.
 * @param s string to be measured
 * @param max maximum number of characters to search for the string end
 * @return length of s or max, whichever is smaller
 */
static size_t strnlen(const char *s, size_t max)
{
	register const char *p;
	for(p = s; *p && max--; ++p);
	return (p - s);
}
#endif

#ifndef HAVE_STRNDUP
/** Copies a string.
 * Returned string needs to be freed
 * @param s string to be copied
 * @param n maximum number of characters to copy
 * @return pointer to the new string on success, NULL on error
 */
char *strndup(const char *s, size_t n)
{
	size_t len = strnlen(s, n);
	char *new = (char *) malloc(len + 1);

	if(new == NULL) {
		return NULL;
	}

	new[len] = '\0';
	return (char *)memcpy(new, s, len);
}
#endif

void wordsplit_free(char **ws)
{
	if(ws) {
		char **c;
		for(c = ws; *c; c++) {
			free(*c);
		}
		free(ws);
	}
}

char **wordsplit(const char *str)
{
	const char *c = str, *end;
	char **out = NULL, **outsave;
	size_t count = 0;

	if(str == NULL) {
		errno = EINVAL;
		return NULL;
	}

	for(c = str; isspace(*c); c++);
	while(*c) {
		size_t wordlen = 0;

		/* extend our array */
		outsave = out;
		if((out = realloc(out, (count + 1) * sizeof(char*))) == NULL) {
			out = outsave;
			goto error;
		}

		/* calculate word length and check for unbalanced quotes */
		for(end = c; *end && !isspace(*end); end++) {
			if(*end == '\'' || *end == '"') {
				char quote = *end;
				while(*(++end) && *end != quote) {
					if(*end == '\\' && *(end + 1) == quote) {
						end++;
					}
					wordlen++;
				}
				if(*end != quote) {
					errno = EINVAL;
					goto error;
				}
			} else {
				if(*end == '\\' && (end[1] == '\'' || end[1] == '"')) {
					end++; /* skip the '\\' */
				}
				wordlen++;
			}
		}

		if(wordlen == (size_t) (end - c)) {
			/* no internal quotes or escapes, copy it the easy way */
			if((out[count++] = strndup(c, wordlen)) == NULL) {
				goto error;
			}
		} else {
			/* manually copy to remove quotes and escapes */
			char *dest = out[count++] = malloc(wordlen + 1);
			if(dest == NULL) { goto error; }
			while(c < end) {
				if(*c == '\'' || *c == '"') {
					char quote = *c;
					/* we know there must be a matching end quote,
					 * no need to check for '\0' */
					for(c++; *c != quote; c++) {
						if(*c == '\\' && *(c + 1) == quote) {
							c++;
						}
						*(dest++) = *c;
					}
					c++;
				} else {
					if(*c == '\\' && (c[1] == '\'' || c[1] == '"')) {
						c++; /* skip the '\\' */
					}
					*(dest++) = *(c++);
				}
			}
			*dest = '\0';
		}

		if(*end == '\0') {
			break;
		} else {
			for(c = end + 1; isspace(*c); c++);
		}
	}

	outsave = out;
	if((out = realloc(out, (count + 1) * sizeof(char*))) == NULL) {
		out = outsave;
		goto error;
	}

	out[count++] = NULL;

	return out;

error:
	/* can't use wordsplit_free here because NULL has not been appended */
	while(count) {
		free(out[--count]);
	}
	free(out);
	return NULL;
}