Bump version to 0.0.2.
[dss.git] / string.c
1 #include <string.h>
2 #include <stdlib.h>
3 #include <stdarg.h>
4 #include <assert.h>
5 #include <limits.h>
6 #include <errno.h>
7 #include <pwd.h>
8 #include <sys/types.h>
9 #include <unistd.h>
10
11
12 #include "cmdline.h"
13 #include "gcc-compat.h"
14 #include "log.h"
15 #include "error.h"
16
17 __noreturn void clean_exit(int status);
18
19 /**
20 * Write a message to a dynamically allocated string.
21 *
22 * \param fmt Usual format string.
23 * \param p Result pointer.
24 *
25 * \sa printf(3). */
26 #define VSPRINTF(fmt, p) \
27 { \
28 int n; \
29 size_t size = 100; \
30 p = dss_malloc(size); \
31 while (1) { \
32 va_list ap; \
33 /* Try to print in the allocated space. */ \
34 va_start(ap, fmt); \
35 n = vsnprintf(p, size, fmt, ap); \
36 va_end(ap); \
37 /* If that worked, return the string. */ \
38 if (n > -1 && n < size) \
39 break; \
40 /* Else try again with more space. */ \
41 if (n > -1) /* glibc 2.1 */ \
42 size = n + 1; /* precisely what is needed */ \
43 else /* glibc 2.0 */ \
44 size *= 2; /* twice the old size */ \
45 p = dss_realloc(p, size); \
46 } \
47 }
48
49 /**
50 * dss' version of realloc().
51 *
52 * \param p Pointer to the memory block, may be \p NULL.
53 * \param size The desired new size.
54 *
55 * A wrapper for realloc(3). It calls \p exit(\p EXIT_FAILURE) on errors,
56 * i.e. there is no need to check the return value in the caller.
57 *
58 * \return A pointer to the newly allocated memory, which is suitably aligned
59 * for any kind of variable and may be different from \a p.
60 *
61 * \sa realloc(3).
62 */
63 __must_check __malloc void *dss_realloc(void *p, size_t size)
64 {
65 /*
66 * No need to check for NULL pointers: If p is NULL, the call
67 * to realloc is equivalent to malloc(size)
68 */
69 assert(size);
70 if (!(p = realloc(p, size))) {
71 DSS_EMERG_LOG("realloc failed (size = %zu), aborting\n",
72 size);
73 clean_exit(EXIT_FAILURE);
74 }
75 return p;
76 }
77
78 /**
79 * dss' version of malloc().
80 *
81 * \param size The desired new size.
82 *
83 * A wrapper for malloc(3) which exits on errors.
84 *
85 * \return A pointer to the allocated memory, which is suitably aligned for any
86 * kind of variable.
87 *
88 * \sa malloc(3).
89 */
90 __must_check __malloc void *dss_malloc(size_t size)
91 {
92 assert(size);
93 void *p = malloc(size);
94
95 if (!p) {
96 DSS_EMERG_LOG("malloc failed (size = %zu), aborting\n",
97 size);
98 clean_exit(EXIT_FAILURE);
99 }
100 return p;
101 }
102
103 /**
104 * dss' version of calloc().
105 *
106 * \param size The desired new size.
107 *
108 * A wrapper for calloc(3) which exits on errors.
109 *
110 * \return A pointer to the allocated and zeroed-out memory, which is suitably
111 * aligned for any kind of variable.
112 *
113 * \sa calloc(3)
114 */
115 __must_check __malloc void *dss_calloc(size_t size)
116 {
117 void *ret = dss_malloc(size);
118
119 memset(ret, 0, size);
120 return ret;
121 }
122
123 /**
124 * dss' version of strdup().
125 *
126 * \param s The string to be duplicated.
127 *
128 * A wrapper for strdup(3). It calls \p exit(EXIT_FAILURE) on errors, i.e.
129 * there is no need to check the return value in the caller.
130 *
131 * \return A pointer to the duplicated string. If \p s was the NULL pointer,
132 * an pointer to an empty string is returned.
133 *
134 * \sa strdup(3)
135 */
136
137 __must_check __malloc char *dss_strdup(const char *s)
138 {
139 char *ret;
140
141 if ((ret = strdup(s? s: "")))
142 return ret;
143 DSS_EMERG_LOG("strdup failed, aborting\n");
144 clean_exit(EXIT_FAILURE);
145 }
146
147 /**
148 * Allocate a sufficiently large string and print into it.
149 *
150 * \param fmt A usual format string.
151 *
152 * Produce output according to \p fmt. No artificial bound on the length of the
153 * resulting string is imposed.
154 *
155 * \return This function either returns a pointer to a string that must be
156 * freed by the caller or aborts without returning.
157 *
158 * \sa printf(3).
159 */
160 __must_check __printf_1_2 __malloc char *make_message(const char *fmt, ...)
161 {
162 char *msg;
163
164 VSPRINTF(fmt, msg);
165 return msg;
166 }
167
168 __printf_1_2 void make_err_msg(const char* fmt,...)
169 {
170 free(dss_error_txt);
171 VSPRINTF(fmt, dss_error_txt);
172 }
173
174 /**
175 * Get the home directory of the current user.
176 *
177 * \return A dynammically allocated string that must be freed by the caller. If
178 * the home directory could not be found, this function returns "/tmp".
179 */
180 __must_check __malloc char *get_homedir(void)
181 {
182 struct passwd *pw = getpwuid(getuid());
183 return dss_strdup(pw? pw->pw_dir : "/tmp");
184 }
185
186 /** \cond LLONG_MAX and LLONG_LIN might not be defined. */
187 #ifndef LLONG_MAX
188 #define LLONG_MAX (1 << (sizeof(long) - 1))
189 #endif
190 #ifndef LLONG_MIN
191 #define LLONG_MIN (-LLONG_MAX - 1LL)
192 #endif
193 /** \endcond */
194
195 /**
196 * Convert a string to a 64-bit signed integer value.
197 *
198 * \param str The string to be converted.
199 * \param value Result pointer.
200 *
201 * \return Standard.
202 *
203 * \sa strtol(3), atoi(3).
204 */
205 int dss_atoi64(const char *str, int64_t *value)
206 {
207 char *endptr;
208 long long tmp;
209
210 errno = 0; /* To distinguish success/failure after call */
211 tmp = strtoll(str, &endptr, 10);
212 if (errno == ERANGE && (tmp == LLONG_MAX || tmp == LLONG_MIN)) {
213 make_err_msg("%s", str);
214 return -E_ATOI_OVERFLOW;
215 }
216 if (errno != 0 && tmp == 0) { /* other error */
217 make_err_msg("%s", str);
218 return -E_STRTOLL;
219 }
220 if (endptr == str) {
221 make_err_msg("%s", str);
222 return -E_ATOI_NO_DIGITS;
223 }
224 if (*endptr != '\0') { /* Further characters after number */
225 make_err_msg("%s", str);
226 return -E_ATOI_JUNK_AT_END;
227 }
228 *value = tmp;
229 return 1;
230 }
231
232 /**
233 * Get the logname of the current user.
234 *
235 * \return A dynammically allocated string that must be freed by the caller. On
236 * errors, the string "unknown user" is returned, i.e. this function never
237 * returns \p NULL.
238 *
239 * \sa getpwuid(3).
240 */
241 __must_check __malloc char *dss_logname(void)
242 {
243 struct passwd *pw = getpwuid(getuid());
244 return dss_strdup(pw? pw->pw_name : "unknown_user");
245 }
246