string.c

   1 /*
   2  * Copyright (C) 2004-2008 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file string.c \brief Memory allocation and string handling functions. */
   8
   9 #include "adu.h"
  10 #include "string.h"
  11 #include <string.h>
  12 #include "error.h"
  13
  14 /**
  15  * Adu's version of realloc().
  16  *
  17  * \param p Pointer to the memory block, may be \p NULL.
  18  * \param size The desired new size.
  19  *
  20  * A wrapper for realloc(3). It calls \p exit(\p EXIT_FAILURE) on errors,
  21  * i.e. there is no need to check the return value in the caller.
  22  *
  23  * \return A pointer to  the newly allocated memory, which is suitably aligned
  24  * for any kind of variable and may be different from \a p.
  25  *
  26  * \sa realloc(3).
  27  */
  28 __must_check __malloc void *adu_realloc(void *p, size_t size)
  29 {
  30         /*
  31          * No need to check for NULL pointers: If p is NULL, the  call
  32          * to realloc is equivalent to malloc(size)
  33          */
  34         assert(size);
  35         if (!(p = realloc(p, size))) {
  36                 EMERG_LOG("realloc failed (size = %zu), aborting\n",
  37                         size);
  38                 exit(EXIT_FAILURE);
  39         }
  40         return p;
  41 }
  42
  43 /**
  44  * Adu's version of malloc().
  45  *
  46  * \param size The desired new size.
  47  *
  48  * A wrapper for malloc(3) which exits on errors.
  49  *
  50  * \return A pointer to the allocated memory, which is suitably aligned for any
  51  * kind of variable.
  52  *
  53  * \sa malloc(3).
  54  */
  55 __must_check __malloc void *adu_malloc(size_t size)
  56 {
  57         assert(size);
  58         void *p = malloc(size);
  59
  60         if (!p) {
  61                 EMERG_LOG("malloc failed (size = %zu),  aborting\n",
  62                         size);
  63                 exit(EXIT_FAILURE);
  64         }
  65         return p;
  66 }
  67
  68 /**
  69  * Adu's version of calloc().
  70  *
  71  * \param size The desired new size.
  72  *
  73  * A wrapper for calloc(3) which exits on errors.
  74  *
  75  * \return A pointer to the allocated and zeroed-out memory, which is suitably
  76  * aligned for any kind of variable.
  77  *
  78  * \sa calloc(3)
  79  */
  80 __must_check __malloc void *adu_calloc(size_t size)
  81 {
  82         void *ret = adu_malloc(size);
  83
  84         memset(ret, 0, size);
  85         return ret;
  86 }
  87
  88 /**
  89  * Adu's version of strdup().
  90  *
  91  * \param s The string to be duplicated.
  92  *
  93  * A wrapper for strdup(3). It calls \p exit(EXIT_FAILURE) on errors, i.e.
  94  * there is no need to check the return value in the caller.
  95  *
  96  * \return A pointer to the duplicated string. If \p s was the NULL pointer,
  97  * an pointer to an empty string is returned.
  98  *
  99  * \sa strdup(3)
 100  */
 101 __must_check __malloc char *adu_strdup(const char *s)
 102 {
 103         char *ret;
 104
 105         if ((ret = strdup(s? s: "")))
 106                 return ret;
 107         EMERG_LOG("strdup failed, aborting\n");
 108         exit(EXIT_FAILURE);
 109 }
 110
 111 /**
 112  * Allocate a sufficiently large string and print into it.
 113  *
 114  * \param fmt A usual format string.
 115  *
 116  * Produce output according to \p fmt. No artificial bound on the length of the
 117  * resulting string is imposed.
 118  *
 119  * \return This function either returns a pointer to a string that must be
 120  * freed by the caller or aborts without returning.
 121  *
 122  * \sa printf(3).
 123  */
 124 __must_check __printf_1_2 __malloc char *make_message(const char *fmt, ...)
 125 {
 126         char *msg;
 127
 128         VSPRINTF(fmt, msg);
 129         return msg;
 130 }
 131
 132 /**
 133  * adu's version of strcat().
 134  *
 135  * \param a String to be appended to.
 136  * \param b String to append.
 137  *
 138  * Append \p b to \p a.
 139  *
 140  * \return If \a a is \p NULL, return a pointer to a copy of \a b, i.e.
 141  * para_strcat(NULL, b) is equivalent to para_strdup(b). If \a b is \p NULL,
 142  * return \a a without making a copy of \a a.  Otherwise, construct the
 143  * concatenation \a c, free \a a (but not \a b) and return \a c.
 144  *
 145  * \sa strcat(3).
 146  */
 147 __must_check __malloc char *adu_strcat(char *a, const char *b)
 148 {
 149         char *tmp;
 150
 151         if (!a)
 152                 return adu_strdup(b);
 153         if (!b)
 154                 return a;
 155         tmp = make_message("%s%s", a, b);
 156         free(a);
 157         return tmp;
 158 }
 159
 160 /** \cond LLONG_MAX and LLONG_LIN might not be defined. */
 161 #ifndef LLONG_MAX
 162 #define LLONG_MAX (1 << (sizeof(long) - 1))
 163 #endif
 164 #ifndef LLONG_MIN
 165 #define LLONG_MIN (-LLONG_MAX - 1LL)
 166 #endif
 167 /** \endcond */
 168
 169 /**
 170  * Convert a string to a 64-bit signed integer value.
 171  *
 172  * \param str The string to be converted.
 173  * \param result Result pointer.
 174  *
 175  * \return Standard.
 176  *
 177  * \sa strtol(3), atoi(3).
 178  */
 179 __must_check int atoi64(const char *str, int64_t *result)
 180 {
 181         char *endptr;
 182         long long tmp;
 183
 184         errno = 0; /* To distinguish success/failure after call */
 185         tmp = strtoll(str, &endptr, 10);
 186         if (errno == ERANGE && (tmp == LLONG_MAX || tmp == LLONG_MIN))
 187                 return -E_ATOI_OVERFLOW;
 188         if (errno != 0 && tmp == 0) /* other error */
 189                 return -E_STRTOLL;
 190         if (endptr == str)
 191                 return -E_ATOI_NO_DIGITS;
 192         if (*endptr != '\0') /* Further characters after number */
 193                 return -E_ATOI_JUNK_AT_END;
 194         *result = tmp;
 195         return 1;
 196 }
 197
 198 /**
 199  * Split a string and return pointers to its parts.
 200  *
 201  * \param args The string to be split.
 202  * \param argv_ptr Pointer to the list of substrings.
 203  * \param delim Delimiter.
 204  *
 205  * This function modifies \a args by replacing each occurance of \a delim by
 206  * zero. A \p NULL terminated array of pointers to char* is allocated dynamically
 207  * and these pointers are initialized to point to the broken-up substrings
 208  * within \a args. A pointer to this array is returned via \a argv_ptr.
 209  *
 210  * \return The number of substrings found in \a args.
 211  */
 212 __must_check unsigned split_args(char *args, char *** const argv_ptr, const char *delim)
 213 {
 214         char *p = args;
 215         char **argv;
 216         size_t n = 0, i, j;
 217
 218         p = args + strspn(args, delim);
 219         for (;;) {
 220                 i = strcspn(p, delim);
 221                 if (!i)
 222                         break;
 223                 p += i;
 224                 n++;
 225                 p += strspn(p, delim);
 226         }
 227         *argv_ptr = adu_malloc((n + 1) * sizeof(char *));
 228         argv = *argv_ptr;
 229         i = 0;
 230         p = args + strspn(args, delim);
 231         while (p) {
 232                 argv[i] = p;
 233                 j = strcspn(p, delim);
 234                 if (!j)
 235                         break;
 236                 p += strcspn(p, delim);
 237                 if (*p) {
 238                         *p = '\0';
 239                         p++;
 240                         p += strspn(p, delim);
 241                 }
 242                 i++;
 243         }
 244         argv[n] = NULL;
 245         return n;
 246 }
 247
 248
 249 static int get_next_word(const char *line, char **word)
 250 {
 251         enum line_state_flags {LSF_HAVE_WORD = 1, LSF_BACKSLASH = 2,
 252                 LSF_QUOTE = 4};
 253         const char *in;
 254         char *out;
 255         int ret, state = 0;
 256
 257         out = adu_malloc(strlen(line) + 1);
 258         *out = '\0';
 259         *word = out;
 260         for (in = line; *in; in++) {
 261                 switch (*in) {
 262                 case '\\':
 263                         if (state & LSF_BACKSLASH) /* \\ */
 264                                 break;
 265                         state |= LSF_BACKSLASH;
 266                         state |= LSF_HAVE_WORD;
 267                         continue;
 268                 case 'n':
 269                 case 't':
 270                         if (state & LSF_BACKSLASH) { /* \n or \t */
 271                                 *out++ = (*in == 'n')? '\n' : '\t';
 272                                 state &= ~LSF_BACKSLASH;
 273                                 continue;
 274                         }
 275                         break;
 276                 case '"':
 277                         if (state & LSF_BACKSLASH) /* \" */
 278                                 break;
 279                         if (state & LSF_QUOTE) {
 280                                 state &= ~LSF_QUOTE;
 281                                 continue;
 282                         }
 283                         state |= LSF_HAVE_WORD;
 284                         state |= LSF_QUOTE;
 285                         continue;
 286                 case ' ':
 287                 case '\t':
 288                 case '\n':
 289                         if (state & LSF_BACKSLASH)
 290                                 break;
 291                         if (state & LSF_QUOTE)
 292                                 break;
 293                         if (state & LSF_HAVE_WORD)
 294                                 goto success;
 295                         /* ignore space at the beginning */
 296                         continue;
 297                 }
 298                 /* copy char */
 299                 state |= LSF_HAVE_WORD;
 300                 *out++ = *in;
 301                 state &= ~LSF_BACKSLASH;
 302         }
 303         ret = 0;
 304         if (!(state & LSF_HAVE_WORD))
 305                 goto out;
 306         ret = -ERRNO_TO_ERROR(EINVAL);
 307         if (state & LSF_BACKSLASH) {
 308                 ERROR_LOG("trailing backslash\n");
 309                 goto out;
 310         }
 311         if (state & LSF_QUOTE) {
 312                 ERROR_LOG("unmatched quote character\n");
 313                 goto out;
 314         }
 315 success:
 316         *out = '\0';
 317         return in - line;
 318 out:
 319         free(*word);
 320         *word = NULL;
 321         return ret;
 322 }
 323
 324 /**
 325  * Free an array of words created by create_argv().
 326  *
 327  * \param argv A pointer previously obtained by \ref create_argv().
 328  */
 329 void free_argv(char **argv)
 330 {
 331         int i;
 332
 333         for (i = 0; argv[i]; i++)
 334                 free(argv[i]);
 335         free(argv);
 336 }
 337
 338 /**
 339  * Split a line into words which are separated by whitespace.
 340  *
 341  * In contrast to gengetopt's string parser, double quotes, backslash-escaped
 342  * characters and special characters like \p \\n are honored. The result
 343  * contains pointers to copies of the words contained in \a line and has to be
 344  * freed by using \ref free_argv().
 345  *
 346  * \param line The line to be split.
 347  * \param result The array of words is returned here.
 348  *
 349  * \return Number of words in \a line, negative on errors.
 350  */
 351 int create_argv(const char *line, char ***result)
 352 {
 353         char *word, **argv = adu_malloc(2 * sizeof(char *));
 354         const char *p;
 355         int ret, num_words;
 356
 357         argv[0] = adu_strdup(line);
 358         for (p = line, num_words = 1; ; p += ret, num_words++) {
 359                 ret = get_next_word(p, &word);
 360                 if (ret < 0)
 361                         goto err;
 362                 if (!ret)
 363                         break;
 364                 argv = adu_realloc(argv, (num_words + 2) * sizeof(char*));
 365                 argv[num_words] = word;
 366         }
 367         argv[num_words] = NULL;
 368         *result = argv;
 369         return num_words;
 370 err:
 371         while (num_words > 0)
 372                 free(argv[--num_words]);
 373         free(argv);
 374         return ret;
 375 }