le_pathIter.h

    1 
    2 //--------------------------------------------------------------------------------------------------
    3 /**
    4  * @page c_pathIter Path Iterator API
    5  *
    6  * @ref le_pathIter.h "API Reference"
    7  *
    8  * <HR>
    9  *
   10  * Paths are text strings that contain nodes separated by character separators.  Paths are used in
   11  * many common applications like file system addressing, URLs, etc. so being able to parse them
   12  * is quite important.
   13  *
   14  * The Path Iterator API is intended for general purpose use and supports UTF-8 null-terminated
   15  * strings and multi-character separators.
   16  *
   17  * This API can be used to iterate over paths, traversing the path node-by-node.  Or creating and
   18  * combining paths together while ensuring that the resultant paths are properly normalized.  For
   19  * instance the following path:
   20  *
   21  * @verbatim
   22     /a//path/to/a///some/../place
   23    @endverbatim
   24  *
   25  * Would be normalized to the path:
   26  *
   27  * @verbatim
   28     /a/path/to/a/place
   29    @endverbatim
   30  *
   31  * @section c_pathIter_create Create a Path Iterator
   32  *
   33  * Before iterating over a path, a path object must first be created by calling either
   34  * @c le_pathIter_Create(), or @c le_pathIter_CreateForUnix().  @c le_pathIter_Create() will
   35  * allow you to create an iterator for one of many different path styles.  While
   36  * @c le_pathIter_CreateForUnix() will create an iterator preconfigured for Unix style paths.
   37  *
   38  * All strings to this API must be formatted as UTF-8 null-terminated strings.
   39  *
   40  * When the path object is no longer needed, it can be deleted by calling le_pathIter_Delete().
   41  *
   42  * @section c_pathIter_iterate Iterating a Path
   43  *
   44  * Once an object is created, the nodes in it can be accessed using @c le_pathIter_GoToNext(), or
   45  * @c le_pathIter_GoToPrev().  To start over at the beginning of the path call
   46  * @c le_pathIter_GoToStart().  To position the iterator at the end of the path, use
   47  * @c le_pathIter_GoToEnd().  On creation, the default position of the iterator is at the end of
   48  * the path.
   49  *
   50  * Code sample, iterate over an entire path:
   51  *
   52  * @code
   53  *
   54  * // Create an iterator object, and move it to the front of the path.
   55  * le_pathIter_Ref_t iteratorRef = le_pathIter_CreateForUnix(myPathPtr);
   56  *
   57  * if (le_pathIter_IsEmpty(iteratorRef))
   58  * {
   59  *     return;
   60  * }
   61  *
   62  * le_pathIter_GoToStart(iteratorRef);
   63  *
   64  * // Now go through all of the path nodes and print out each one.
   65  * do
   66  * {
   67  *     char buffer[BUFFER_SIZE] = { 0 };
   68  *
   69  *     if (le_pathIter_GetCurrentNode(iteratorRef, buffer, BUFFER_SIZE) == LE_OK)
   70  *     {
   71  *         printf("%s\n", buffer);
   72  *     }
   73  * }
   74  * while (le_pathIter_GoToNext(iteratorRef) != LE_NOT_FOUND);
   75  *
   76  * // All done with the iterator, so free it now.
   77  * le_pathIter_Delete(iteratorRef);
   78  *
   79  * @endcode
   80  *
   81  * @note @c le_pathIter_GetNextNode() and @c le_pathIter_GetPreviousNode() treat consecutive
   82  *       separators as a single separator.
   83  *
   84  * @section c_pathIter_absoluteRelative Absolute versus Relative Paths
   85  *
   86  * Absolute paths begin with one or more separators.  Relative paths do not begin with a separator.
   87  * @c le_pathIter_IsAbsolute() can be used to determine if the path is absolute or relative.
   88  *
   89  * @section c_pathIter_modifyPath Modifying Paths
   90  *
   91  * In addition to pure iteration, the path iterator can allow you to modify a path.  For instance,
   92  * you can iterate to a node in the path and use @c le_pathIter_Truncate() to truncate everything at
   93  * and after that point.  While you can use @c le_pathIter_Append() to add new path nodes at the end
   94  * of the path.
   95  *
   96  * Take the following code:
   97  *
   98  * @code
   99  *
  100  * le_pathIter_Ref_t iteratorRef = le_pathIter_CreateForUnix("/a/path/to/a/place");
  101  * char fullPath[PATH_SIZE] = { 0 };
  102  *
  103  * le_pathIter_GoToStart(iteratorRef);
  104  *
  105  * le_pathIter_GoToNext(iteratorRef);
  106  * le_pathIter_GoToNext(iteratorRef);
  107  * le_pathIter_GoToNext(iteratorRef);
  108  *
  109  * le_pathIter_Truncate(iteratorRef);
  110  *
  111  * le_pathIter_Append(iteratorRef, "nowhere");
  112  *
  113  * le_pathIter_GetPath(iteratorRef, fullPath, PATH_SIZE);
  114  *
  115  * LE_ASSERT(strcmp(fullPath, "/a/path/to/nowhere") == 0);
  116  *
  117  * @endcode
  118  *
  119  * Note that @c le_pathIter_Append() will also normalize paths as it appends.  So, the following
  120  * example has the same effect as the previous one.
  121  *
  122  * @code
  123  *
  124  * le_pathIter_Ref_t iteratorRef = le_pathIter_CreateForUnix("/a/path/to/a/place");
  125  * char fullPath[PATH_SIZE] = { 0 };
  126  *
  127  * le_pathIter_Append(iteratorRef, "../../nowhere");
  128  * le_pathIter_GetPath(iteratorRef, fullPath, PATH_SIZE);
  129  *
  130  * le_pathIter_GetPath(iteratorRef, fullPath, PATH_SIZE);
  131  *
  132  * LE_ASSERT(strcmp(fullPath, "/a/path/to/nowhere") == 0);
  133  *
  134  * @endcode
  135  *
  136  * <HR>
  137  *
  138  * Copyright (C) Sierra Wireless Inc.
  139  * license.
  140  */
  141 //--------------------------------------------------------------------------------------------------
  142 /** @file le_pathIter.h
  143  *
  144  * Legato @ref c_pathIter include file.
  145  *
  146  * Copyright (C) Sierra Wireless Inc.
  147  * license.
  148  */
  149 //--------------------------------------------------------------------------------------------------
  150 
  151 #ifndef LEGATO_PATH_ITER_INCLUDE_GUARD
  152 #define LEGATO_PATH_ITER_INCLUDE_GUARD
  153 
  154 
  155 //--------------------------------------------------------------------------------------------------
  156 /**
  157  * Objects of this type are used to iterate and manipulate path strings.
  158  */
  159 //--------------------------------------------------------------------------------------------------
  160 typedef struct le_pathIter_t* le_pathIter_Ref_t;
  161 
  162 
  163 //--------------------------------------------------------------------------------------------------
  164 /**
  165  * Create a new path iterator object.  On creation, the default position of the iterator is at the
  166  * end of the path.
  167  *
  168  * @return A new path object setup with the given parameters.
  169  */
  170 //--------------------------------------------------------------------------------------------------
  171 le_pathIter_Ref_t le_pathIter_Create
  172 (
  173     const char* pathPtr,        ///< [IN] Optional.  Pointer to the inital path to use.
  174     const char* separatorPtr,   ///< [IN] Required.  Path separator to use.  The separator can not
  175                                 ///<      be NULL or empty.
  176     const char* parentSpecPtr,  ///< [IN] Optional.  Used to traverse upwards in a path.  Leave as
  177                                 ///<      NULL or empty to not use.  This acts like how ".." is used
  178                                 ///<      in a filesystem path.
  179     const char* currentSpecPtr  ///< [IN] Optional.  Used to refer to a current node.  Much like how
  180                                 ///<      a '.' is used in a filesystem path.
  181 );
  182 
  183 
  184 //--------------------------------------------------------------------------------------------------
  185 /**
  186  * Create a new path iterator object that is pre-configured for Unix styled paths.    On creation,
  187  * the default position of the iterator is at the end of the path.
  188  *
  189  * The parameters are configured as follows:
  190  *
  191  *  - separator:   "/"
  192  *  - parentSpec:  ".."
  193  *  - currentSpec: "."
  194  *
  195  * @return A new path iterator object that's ready for iterating on Unix style paths.
  196  */
  197 //--------------------------------------------------------------------------------------------------
  198 le_pathIter_Ref_t le_pathIter_CreateForUnix
  199 (
  200     const char* pathPtr  ///<  [IN] Optional.  Create an iterator for this path, or start with an
  201                          ///<       empty path.
  202 );
  203 
  204 
  205 //--------------------------------------------------------------------------------------------------
  206 /**
  207  * Create a clone of an existing path iterator object.
  208  *
  209  * @return A new path iterator object that is a duplicate of the original one.
  210  */
  211 //--------------------------------------------------------------------------------------------------
  212 le_pathIter_Ref_t le_pathIter_Clone
  213 (
  214     le_pathIter_Ref_t originalRef  ///< [IN] The path object to duplicate.
  215 );
  216 
  217 
  218 //--------------------------------------------------------------------------------------------------
  219 /**
  220  * Delete an iterator object and free it's memory.
  221  */
  222 //--------------------------------------------------------------------------------------------------
  223 void le_pathIter_Delete
  224 (
  225     le_pathIter_Ref_t iterRef  ///< [IN] The iterator object to destroy.
  226 );
  227 
  228 
  229 //--------------------------------------------------------------------------------------------------
  230 /**
  231  * Read the string that is being used to represent path separators in this iterator object.
  232  */
  233 //--------------------------------------------------------------------------------------------------
  234 le_result_t le_pathIter_GetSeparator
  235 (
  236     le_pathIter_Ref_t iterRef,  ///< [IN] The iterator object to read.
  237     char* bufferPtr,            ///< [OUT] The string buffer to write to.
  238     size_t bufferSize           ///< [IN] The size of the buffer being written to.
  239 );
  240 
  241 
  242 //--------------------------------------------------------------------------------------------------
  243 /**
  244  * Read the string that represents parent nodes in a path string.  By for Unix style paths this is
  245  * "..".  If an empty string is used, then it is ignored for the purposes of appending and
  246  * normalizing paths.
  247  */
  248 //--------------------------------------------------------------------------------------------------
  249 le_result_t le_pathIter_GetParentSpecifier
  250 (
  251     le_pathIter_Ref_t iterRef,  ///< [IN] The iterator object to read.
  252     char* bufferPtr,            ///< [OUT] The string buffer to write to.
  253     size_t bufferSize           ///< [IN] The size of the buffer being written to.
  254 );
  255 
  256 
  257 //--------------------------------------------------------------------------------------------------
  258 /**
  259  * Read the iterators string for the current node specifier.  For Unix style paths for this is ".".
  260  * If an empty string is used, then this is ignored for the purposes of appending and normalizing
  261  * paths.
  262  */
  263 //--------------------------------------------------------------------------------------------------
  264 le_result_t le_pathIter_GetCurrentSpecifier
  265 (
  266     le_pathIter_Ref_t iterRef,  ///< [IN] The iterator object to read.
  267     char* bufferPtr,            ///< [OUT] The string buffer to write to.
  268     size_t bufferSize           ///< [IN] The size of the string buffer being written to.
  269 );
  270 
  271 
  272 //--------------------------------------------------------------------------------------------------
  273 /**
  274  * Get a copy of the path currently contained within the iterator.
  275  *
  276  * @return LE_OK if the copy is successful.
  277  *         LE_OVERFLOW if the buffer isn't big enough for the path string.
  278  */
  279 //--------------------------------------------------------------------------------------------------
  280 le_result_t le_pathIter_GetPath
  281 (
  282     le_pathIter_Ref_t iterRef,  ///< [IN] The iterator object to read.
  283     char* bufferPtr,            ///< [OUT] The string buffer to write to.
  284     size_t bufferSize           ///< [IN] The size of the buffer being written to.
  285 );
  286 
  287 
  288 //--------------------------------------------------------------------------------------------------
  289 /**
  290  * Jump the iterator to the beginning of the path.
  291  *
  292  * @return LE_OK if the move was successful.
  293  *         LE_NOT_FOUND if the path is empty, or only contains a separator.
  294  */
  295 //--------------------------------------------------------------------------------------------------
  296 le_result_t le_pathIter_GoToStart
  297 (
  298     le_pathIter_Ref_t iterRef  ///< [IN] The iterator object to update.
  299 );
  300 
  301 
  302 //--------------------------------------------------------------------------------------------------
  303 /**
  304  * Jump the iterator to the end of the path.
  305  *
  306  * @return LE_OK if the move was successful.
  307  *         LE_NOT_FOUND if the path is empty, or only contains a separator.
  308  */
  309 //--------------------------------------------------------------------------------------------------
  310 le_result_t le_pathIter_GoToEnd
  311 (
  312     le_pathIter_Ref_t iterRef  ///< [IN] The iterator object to update.
  313 );
  314 
  315 
  316 //--------------------------------------------------------------------------------------------------
  317 /**
  318  * Move to the next node in the path.
  319  *
  320  * @return LE_OK if the itrator was successful in jumping to the next node.  LE_NOT_FOUND is
  321  *         returned if there are no more nodes to move to in the path.
  322  */
  323 //--------------------------------------------------------------------------------------------------
  324 le_result_t le_pathIter_GoToNext
  325 (
  326     le_pathIter_Ref_t iterRef  ///< [IN] The iterator object to update.
  327 );
  328 
  329 
  330 //--------------------------------------------------------------------------------------------------
  331 /**
  332  * Move to the previous node in the path.
  333  *
  334  * @return LE_OK if the iterator was successfuly moved, LE_NOT_FOUND if there are no prior nodes to
  335  *         move to.
  336  */
  337 //--------------------------------------------------------------------------------------------------
  338 le_result_t le_pathIter_GoToPrev
  339 (
  340     le_pathIter_Ref_t iterRef  ///< [IN] The iterator object to update.
  341 );
  342 
  343 
  344 //--------------------------------------------------------------------------------------------------
  345 /**
  346  * Get the text for the node the itrator is pointing at.
  347  *
  348  * @return
  349  *      LE_OK if succesful.
  350  *      LE_OVERFLOW if the bufferPtr is too small to hold the whole string.
  351  *      LE_NOT_FOUND if the iterator is at the end of the path.  Or if the path is empty, or simply
  352  *      consists of a separator.
  353  */
  354 //--------------------------------------------------------------------------------------------------
  355 le_result_t le_pathIter_GetCurrentNode
  356 (
  357     le_pathIter_Ref_t iterRef,  ///< [IN] The iterator object to read.
  358     char* bufferPtr,            ///< [OUT] The utf-8 formatted text buffer to write to.
  359     size_t bufferSize           ///< [IN] The size in bytes of the text buffer.
  360 );
  361 
  362 
  363 //--------------------------------------------------------------------------------------------------
  364 /**
  365  * Truncate the path at the current iterator node.  If the iterator is at the beginning of the
  366  * path, then the whole path is cleared.  If the iterator is at the end of the path, then nothing
  367  * happens.
  368  *
  369  * Once done, then the iterator will be pointing at the new end of the path.
  370  */
  371 //--------------------------------------------------------------------------------------------------
  372 void le_pathIter_Truncate
  373 (
  374     le_pathIter_Ref_t iterRef  ///< [IN] The iterator to update.
  375 );
  376 
  377 
  378 //--------------------------------------------------------------------------------------------------
  379 /**
  380  * Take the new string path and combine it with the object's existing path.
  381  *
  382  * @note This function looks for the current and parent node strings and treats them specially.
  383  *       So, (assuming defaults,) combining the path "/a/b" with the path "../x" will give you the
  384  *       combined path of: "/a/x".
  385  *
  386  * @note Appending a non-relative path onto an existing path effectivly replaces the current path,
  387  *       for example, appending /a/rooted/path, onto the existing /a/seperate/path will given you
  388  *       the path: /a/rooted/path.
  389  *
  390  * @note This will automatically reset the internal iterator to point at the end of the newly formed
  391  *       path.  Also, this function always appends to the end of a path, ignoring the current
  392  *       position of the iterator.
  393  *
  394  * @return
  395  *      LE_OK if successful.
  396  *      LE_OVERFLOW if the output buffer is too small for the new string.
  397  *      LE_UNDERFLOW if combining the path the new path tries to traverse past the root.  For
  398  *        example: "/a/b" + "../../../x" will result in LE_UNDERFLOW.  However if the base path is
  399  *        relative, "a/b", then the resulting string will be "../x" and a return code of LE_OK.
  400  */
  401 //--------------------------------------------------------------------------------------------------
  402 le_result_t le_pathIter_Append
  403 (
  404     le_pathIter_Ref_t iterRef,  ///< [IN] The path object to write to.
  405     const char* pathStr         ///< [IN] The new path segment to append.
  406 );
  407 
  408 
  409 //--------------------------------------------------------------------------------------------------
  410 /**
  411  * Is this an absolute or relative path?
  412  *
  413  * @return True if the path is absolute, that is that it begins with a separator.  False if the path
  414  *         is considered relative.
  415  */
  416 //--------------------------------------------------------------------------------------------------
  417 bool le_pathIter_IsAbsolute
  418 (
  419     le_pathIter_Ref_t iterRef  ///< [IN] The iterator object to read.
  420 );
  421 
  422 
  423 //--------------------------------------------------------------------------------------------------
  424 /**
  425  * Is the path object holding an empty string?
  426  *
  427  * @return True if the path is empty, false if not.
  428  */
  429 //--------------------------------------------------------------------------------------------------
  430 bool le_pathIter_IsEmpty
  431 (
  432     le_pathIter_Ref_t iterRef  ///< The path object to read.
  433 );
  434 
  435 
  436 #endif  // LEGATO_PATH_ITER_INCLUDE_GUARD
le_pathIter_GetPath
le_result_t le_pathIter_GetPath(le_pathIter_Ref_t iterRef, char *bufferPtr, size_t bufferSize)
le_pathIter_Truncate
void le_pathIter_Truncate(le_pathIter_Ref_t iterRef)
le_pathIter_IsAbsolute
bool le_pathIter_IsAbsolute(le_pathIter_Ref_t iterRef)
le_result_t
le_result_t
Definition: le_basics.h:35
le_pathIter_IsEmpty
bool le_pathIter_IsEmpty(le_pathIter_Ref_t iterRef)
le_pathIter_GetCurrentSpecifier
le_result_t le_pathIter_GetCurrentSpecifier(le_pathIter_Ref_t iterRef, char *bufferPtr, size_t bufferSize)
le_pathIter_GoToEnd
le_result_t le_pathIter_GoToEnd(le_pathIter_Ref_t iterRef)
le_pathIter_Create
le_pathIter_Ref_t le_pathIter_Create(const char *pathPtr, const char *separatorPtr, const char *parentSpecPtr, const char *currentSpecPtr)
le_pathIter_Delete
void le_pathIter_Delete(le_pathIter_Ref_t iterRef)
le_pathIter_GetParentSpecifier
le_result_t le_pathIter_GetParentSpecifier(le_pathIter_Ref_t iterRef, char *bufferPtr, size_t bufferSize)
le_pathIter_GetCurrentNode
le_result_t le_pathIter_GetCurrentNode(le_pathIter_Ref_t iterRef, char *bufferPtr, size_t bufferSize)
le_pathIter_GoToStart
le_result_t le_pathIter_GoToStart(le_pathIter_Ref_t iterRef)
le_pathIter_GoToNext
le_result_t le_pathIter_GoToNext(le_pathIter_Ref_t iterRef)
le_pathIter_GetSeparator
le_result_t le_pathIter_GetSeparator(le_pathIter_Ref_t iterRef, char *bufferPtr, size_t bufferSize)
le_pathIter_Ref_t
struct le_pathIter_t * le_pathIter_Ref_t
Definition: le_pathIter.h:160
le_pathIter_Append
le_result_t le_pathIter_Append(le_pathIter_Ref_t iterRef, const char *pathStr)
le_pathIter_CreateForUnix
le_pathIter_Ref_t le_pathIter_CreateForUnix(const char *pathPtr)
le_pathIter_Clone
le_pathIter_Ref_t le_pathIter_Clone(le_pathIter_Ref_t originalRef)
le_pathIter_GoToPrev
le_result_t le_pathIter_GoToPrev(le_pathIter_Ref_t iterRef)