text: /*
   * Prototypes for vector handling.
   *
   * A vector is a list of strings, with dynamic resizing of the list as new
   * strings are added and support for various operations on strings (such as
   * splitting them on delimiters).
   *
   * Vectors require list of strings, not arbitrary binary data, and cannot
   * handle data elements containing nul characters.
   *
   * This is based on the util/vector.c library, but that library uses xmalloc
   * routines to exit the program if memory allocation fails.  This is a
   * modified version of the vector library that instead returns false on
   * failure to allocate memory, allowing the caller to do appropriate recovery.
   *
   * Only the portions of the vector library used by PAM modules are
   * implemented.
   *
   * The canonical version of this file is maintained in the rra-c-util package,
   * which can be found at <https://www.eyrie.org/~eagle/software/rra-c-util/>.
   *
   * Written by Russ Allbery <eagle@eyrie.org>
   * Copyright 2010-2011, 2014
   *     The Board of Trustees of the Leland Stanford Junior University
   *
   * Copying and distribution of this file, with or without modification, are
   * permitted in any medium without royalty provided the copyright notice and
   * this notice are preserved.  This file is offered as-is, without any
   * warranty.
   *
   * SPDX-License-Identifier: FSFAP
   */
  
  #ifndef PAM_UTIL_VECTOR_H
  #define PAM_UTIL_VECTOR_H 1
  
  #include <config.h>
  #include <portable/macros.h>
  #include <portable/stdbool.h>
  
  #include <stddef.h>
  
  struct vector {
      size_t count;
      size_t allocated;
      char **strings;
  };
  
  BEGIN_DECLS
  
  /* Default to a hidden visibility for all util functions. */
  #pragma GCC visibility push(hidden)
  
  /* Create a new, empty vector.  Returns NULL on memory allocation failure. */
  struct vector *vector_new(void) __attribute__((__malloc__));
  
  /*
   * Create a new vector that's a copy of an existing vector.  Returns NULL on
   * memory allocation failure.
   */
  struct vector *vector_copy(const struct vector *)
      __attribute__((__malloc__, __nonnull__));
  
  /*
   * Add a string to a vector.  Resizes the vector if necessary.  Returns false
   * on failure to allocate memory.
   */
  bool vector_add(struct vector *, const char *string)
      __attribute__((__nonnull__));
  
  /*
   * Resize the array of strings to hold size entries.  Saves reallocation work
   * in vector_add if it's known in advance how many entries there will be.
   * Returns false on failure to allocate memory.
   */
  bool vector_resize(struct vector *, size_t size) __attribute__((__nonnull__));
  
  /*
   * Reset the number of elements to zero, freeing all of the strings for a
   * regular vector, but not freeing the strings array (to cut down on memory
   * allocations if the vector will be reused).
   */
  void vector_clear(struct vector *) __attribute__((__nonnull__));
  
  /* Free the vector and all resources allocated for it. */
  void vector_free(struct vector *);
  
  /*
   * Split functions build a vector from a string.  vector_split_multi splits on
   * a set of characters.  If the vector argument is NULL, a new vector is
   * allocated; otherwise, the provided one is reused.  Returns NULL on memory
   * allocation failure, after which the provided vector may have been modified
   * to only have partial results.
   *
   * Empty strings will yield zero-length vectors.  Adjacent delimiters are
   * treated as a single delimiter by vector_split_multi.  Any leading or
   * trailing delimiters are ignored, so this function will never create
   * zero-length strings (similar to the behavior of strtok).
   */
  struct vector *vector_split_multi(const char *string, const char *seps,
                                    struct vector *)
      __attribute__((__nonnull__(1, 2)));
  
  /*
   * Exec the given program with the vector as its arguments.  Return behavior
   * is the same as execv.  Note the argument order is different than the other
   * vector functions (but the same as execv).  The vector_exec_env variant
   * calls execve and passes in the environment for the program.
   */
  int vector_exec(const char *path, struct vector *)
      __attribute__((__nonnull__));
  int vector_exec_env(const char *path, struct vector *, const char *const env[])
      __attribute__((__nonnull__));
  
  /* Undo default visibility change. */
  #pragma GCC visibility pop
  
  END_DECLS
  
  #endif /* UTIL_VECTOR_H */
  