Fix typo in documentation of --logfile.
[dss.git] / str.c
1 /*
2 * Copyright (C) 2004-2010 Andre Noll <maan@tuebingen.mpg.de>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6 #include <string.h>
7 #include <stdlib.h>
8 #include <stdio.h>
9 #include <stdarg.h>
10 #include <assert.h>
11 #include <limits.h>
12 #include <errno.h>
13 #include <pwd.h>
14 #include <sys/types.h>
15 #include <unistd.h>
16
17
18 #include "gcc-compat.h"
19 #include "log.h"
20 #include "err.h"
21 #include "str.h"
22
23 /**
24 * Write a message to a dynamically allocated string.
25 *
26 * \param fmt Usual format string.
27 * \param p Result pointer.
28 *
29 * \sa printf(3). */
30 #define VSPRINTF(fmt, p) \
31 { \
32 int n; \
33 size_t size = 100; \
34 p = dss_malloc(size); \
35 while (1) { \
36 va_list ap; \
37 /* Try to print in the allocated space. */ \
38 va_start(ap, fmt); \
39 n = vsnprintf(p, size, fmt, ap); \
40 va_end(ap); \
41 /* If that worked, return the string. */ \
42 if (n > -1 && n < size) \
43 break; \
44 /* Else try again with more space. */ \
45 if (n > -1) /* glibc 2.1 */ \
46 size = n + 1; /* precisely what is needed */ \
47 else /* glibc 2.0 */ \
48 size *= 2; /* twice the old size */ \
49 p = dss_realloc(p, size); \
50 } \
51 }
52
53 /**
54 * dss' version of realloc().
55 *
56 * \param p Pointer to the memory block, may be \p NULL.
57 * \param size The desired new size.
58 *
59 * A wrapper for realloc(3). It calls \p exit(\p EXIT_FAILURE) on errors,
60 * i.e. there is no need to check the return value in the caller.
61 *
62 * \return A pointer to the newly allocated memory, which is suitably aligned
63 * for any kind of variable and may be different from \a p.
64 *
65 * \sa realloc(3).
66 */
67 __must_check __malloc void *dss_realloc(void *p, size_t size)
68 {
69 /*
70 * No need to check for NULL pointers: If p is NULL, the call
71 * to realloc is equivalent to malloc(size)
72 */
73 assert(size);
74 if (!(p = realloc(p, size))) {
75 DSS_EMERG_LOG(("realloc failed (size = %zu), aborting\n",
76 size));
77 exit(EXIT_FAILURE);
78 }
79 return p;
80 }
81
82 /**
83 * dss' version of malloc().
84 *
85 * \param size The desired new size.
86 *
87 * A wrapper for malloc(3) which exits on errors.
88 *
89 * \return A pointer to the allocated memory, which is suitably aligned for any
90 * kind of variable.
91 *
92 * \sa malloc(3).
93 */
94 __must_check __malloc void *dss_malloc(size_t size)
95 {
96 void *p;
97 assert(size);
98 p = malloc(size);
99
100 if (!p) {
101 DSS_EMERG_LOG(("malloc failed (size = %zu), aborting\n",
102 size));
103 exit(EXIT_FAILURE);
104 }
105 return p;
106 }
107
108 /**
109 * dss' version of calloc().
110 *
111 * \param size The desired new size.
112 *
113 * A wrapper for calloc(3) which exits on errors.
114 *
115 * \return A pointer to the allocated and zeroed-out memory, which is suitably
116 * aligned for any kind of variable.
117 *
118 * \sa calloc(3)
119 */
120 __must_check __malloc void *dss_calloc(size_t size)
121 {
122 void *ret = dss_malloc(size);
123
124 memset(ret, 0, size);
125 return ret;
126 }
127
128 /**
129 * dss' version of strdup().
130 *
131 * \param s The string to be duplicated.
132 *
133 * A wrapper for strdup(3). It calls \p exit(EXIT_FAILURE) on errors, i.e.
134 * there is no need to check the return value in the caller.
135 *
136 * \return A pointer to the duplicated string. If \p s was the NULL pointer,
137 * an pointer to an empty string is returned.
138 *
139 * \sa strdup(3)
140 */
141
142 __must_check __malloc char *dss_strdup(const char *s)
143 {
144 char *ret;
145
146 if ((ret = strdup(s? s: "")))
147 return ret;
148 DSS_EMERG_LOG(("strdup failed, aborting\n"));
149 exit(EXIT_FAILURE);
150 }
151
152 /**
153 * Allocate a sufficiently large string and print into it.
154 *
155 * \param fmt A usual format string.
156 *
157 * Produce output according to \p fmt. No artificial bound on the length of the
158 * resulting string is imposed.
159 *
160 * \return This function either returns a pointer to a string that must be
161 * freed by the caller or aborts without returning.
162 *
163 * \sa printf(3).
164 */
165 __must_check __printf_1_2 __malloc char *make_message(const char *fmt, ...)
166 {
167 char *msg;
168
169 VSPRINTF(fmt, msg);
170 return msg;
171 }
172
173 /**
174 * Get the home directory of the current user.
175 *
176 * \return A dynammically allocated string that must be freed by the caller. If
177 * the home directory could not be found, this function returns "/tmp".
178 */
179 __must_check __malloc char *get_homedir(void)
180 {
181 struct passwd *pw = getpwuid(getuid());
182 return dss_strdup(pw? pw->pw_dir : "/tmp");
183 }
184
185 /**
186 * Convert a string to a 64-bit signed integer value.
187 *
188 * \param str The string to be converted.
189 * \param value Result pointer.
190 *
191 * \return Standard.
192 *
193 * \sa strtol(3), atoi(3).
194 */
195 int dss_atoi64(const char *str, int64_t *value)
196 {
197 char *endptr;
198 long long tmp;
199
200 errno = 0; /* To distinguish success/failure after call */
201 tmp = strtoll(str, &endptr, 10);
202 if (errno == ERANGE && (tmp == LLONG_MAX || tmp == LLONG_MIN))
203 return -E_ATOI_OVERFLOW;
204 if (errno != 0 && tmp == 0) /* other error */
205 return -E_STRTOLL;
206 if (endptr == str)
207 return -E_ATOI_NO_DIGITS;
208 if (*endptr != '\0') /* Further characters after number */
209 return -E_ATOI_JUNK_AT_END;
210 *value = tmp;
211 return 1;
212 }
213
214 /**
215 * Get the logname of the current user.
216 *
217 * \return A dynammically allocated string that must be freed by the caller. On
218 * errors, the string "unknown user" is returned, i.e. this function never
219 * returns \p NULL.
220 *
221 * \sa getpwuid(3).
222 */
223 __must_check __malloc char *dss_logname(void)
224 {
225 struct passwd *pw = getpwuid(getuid());
226 return dss_strdup(pw? pw->pw_name : "unknown_user");
227 }
228
229 /**
230 * Split string and return pointers to its parts.
231 *
232 * \param args The string to be split.
233 * \param argv_ptr Pointer to the list of substrings.
234 * \param delim Delimiter.
235 *
236 * This function modifies \a args by replacing each occurance of \a delim by
237 * zero. A \p NULL-terminated array of pointers to char* is allocated dynamically
238 * and these pointers are initialized to point to the broken-up substrings
239 * within \a args. A pointer to this array is returned via \a argv_ptr.
240 *
241 * \return The number of substrings found in \a args.
242 */
243 unsigned split_args(char *args, char *** const argv_ptr, const char *delim)
244 {
245 char *p;
246 char **argv;
247 size_t n = 0, i, j;
248
249 p = args + strspn(args, delim);
250 for (;;) {
251 i = strcspn(p, delim);
252 if (!i)
253 break;
254 p += i;
255 n++;
256 p += strspn(p, delim);
257 }
258 *argv_ptr = dss_malloc((n + 1) * sizeof(char *));
259 argv = *argv_ptr;
260 i = 0;
261 p = args + strspn(args, delim);
262 while (p) {
263 argv[i] = p;
264 j = strcspn(p, delim);
265 if (!j)
266 break;
267 p += strcspn(p, delim);
268 if (*p) {
269 *p = '\0';
270 p++;
271 p += strspn(p, delim);
272 }
273 i++;
274 }
275 argv[n] = NULL;
276 return n;
277 }