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