Subversion Repositories QNX 8.QNX8 IFS tool

// buffer.c

// standard C includes

#include <stdio.h>

#include <stddef.h>

#include <stdlib.h>

#include <stdarg.h>

#include <stdint.h> // for SIZE_MAX

#include <string.h>

#include <fcntl.h>

#include <sys/stat.h>

#include <locale.h>

#include <errno.h>

// our own includes

#include "buffer.h"

// compiler-specific glue

#ifdef _MSC_VER

#include <io.h>

#include <direct.h>

#define strdup(s) _strdup((s))

#define mkdir(p,m) _mkdir ((p))

#define strncasecmp(s1,s2,l) _strnicmp ((s1), (s2), (l))

#define strtok_r(s,delim,ctx) strtok_s ((s), (delim), (ctx))

#define fseek(fp,off,m) _fseeki64 ((fp), (off), (m))

#define ftell(fp) _ftelli64 ((fp))

#if (SIZE_MAX == UINT64_MAX)

#define ssize_t signed long long

#else // SIZE_MAX != UINT64_MAX

#define ssize_t signed long

#endif // SIZE_MAX == UINT64_MAX

#define thread_local __declspec(thread)

#else // !_MSC_VER

#define thread_local __thread

#endif // _MSC_VER

// Windows-specific long path handling facilities

#if defined(_WIN32) && (!defined(MAXPATHLEN) || (MAXPATHLEN <= 260))

extern void *__stdcall CreateFileW (const wchar_t *lpFileName, unsigned long dwDesiredAccess, unsigned long dwShareMode, void *lpSecurityAttributes, unsigned long dwCreationDisposition, unsigned long dwFlagsAndAttributes, void *hTemplateFile);

extern int __stdcall MultiByteToWideChar (unsigned int CodePage, unsigned long dwFlags, const char *lpMultiByteStr, int cbMultiByte, wchar_t *lpWideCharStr, int cchWideChar);

extern unsigned long __stdcall GetFullPathNameW (const wchar_t *lpFileName, unsigned long nBufferLength, wchar_t *lpBuffer, wchar_t **lpFilePart);

extern int __stdcall CloseHandle (void *hObject);

extern int __stdcall AreFileApisANSI (void);

thread_local static wchar_t wide_pathname[32768] = L"";

thread_local static wchar_t nt_pathname[32768] = L"\\\\?\\"; // initialized to NT prefix once and for all

thread_local static void *nt_filehandle = NULL;

thread_local static int intermediary_fd = -1;

#endif // defined(_WIN32) && (!defined(MAXPATHLEN) || (MAXPATHLEN <= 260))

void Buffer_Forget (buffer_t *buffer)

{

   // this function forgets a buffer's contents, freeing its associated memory buffer,

   // and resets the buffer_t structure.

   if (buffer->bytes != NULL)

      free (buffer->bytes); // free buffer data

   buffer->bytes = NULL;

   buffer->size = 0; // reset data size

   return; // finished, buffer structure is virgin again

}

int Buffer_Reset (buffer_t *buffer)

{

   // this function makes a buffer contain only an empty string (with a null terminator), of size 0.

   // Returns 1 on success, 0 on error (in which case errno is set to ENOMEM).

   void *reallocated_ptr;

   size_t padding;

   // first, reallocate space for an empty string

   reallocated_ptr = realloc (buffer->bytes, sizeof (size_t)); // always null-terminate buffers, but never report the null terminator

   if (reallocated_ptr == NULL)

      return (0); // on failure, return an error value (errno already set to ENOMEM)

   buffer->bytes = reallocated_ptr; // save pointer to reallocated data

   buffer->size = 0; // and reset buffer size

   for (padding = 0; padding < sizeof (size_t); padding++)

      buffer->bytes[padding] = 0; // always null-terminate buffers, silently

   return (1); // buffer emptied successfully, return SUCCESS

}

int Buffer_Append (buffer_t *buffer, const void *data, const size_t data_size)

{

   // this function appends the contents of data to a buffer's data.

   // Buffer is always null-terminated, but the terminator is NOT counted in the buffer's length.

   // Returns 1 on success, 0 on error (in which case errno is set to ENOMEM).

   void *reallocated_ptr;

   size_t padding;

   // first, reallocate space to hold data_size bytes more

   reallocated_ptr = realloc (buffer->bytes, buffer->size + data_size + sizeof (size_t)); // always null-terminate buffers, but never report the null terminator

   if (reallocated_ptr == NULL)

      return (0); // on failure, return an error value (errno already set to ENOMEM)

   buffer->bytes = reallocated_ptr; // save pointer to reallocated data

   if (data_size > 0)

   {

      if (data != NULL)

         memcpy (&buffer->bytes[buffer->size], data, data_size); // if data points to something, write new data at the end

      else

         memset (&buffer->bytes[buffer->size], 0, data_size); // or, if data is NULL, set the extra space to zero

      buffer->size += data_size; // and increment buffer size

   }

   for (padding = 0; padding < sizeof (size_t); padding++)

      buffer->bytes[buffer->size + padding] = 0; // always null-terminate buffers, silently

   return (1); // buffer appended successfully, return SUCCESS

}

int Buffer_AppendFormattedCString (buffer_t *buffer, const char *fmt_string, ...)

{

   // this function appends some printf-style formatted data to a buffer's data.

   // Buffer is always null-terminated, but the terminator is NOT counted in the buffer's length.

   // Returns 1 on success, 0 on error (in which case errno is set to ENOMEM).

   void *reallocated_ptr;

   va_list varargs_list;

   va_list varargs_copy;

   char *saved_locale;

   size_t extra_size;

   size_t padding;

   saved_locale = setlocale (LC_ALL, NULL); // get the current locale

   if (saved_locale != NULL)

      saved_locale = strdup (saved_locale); // preserve it

   setlocale (LC_ALL, "C"); // format everything in the POSIX (international) locale

   // first, concatenate varargs and see how much extra space we need

   va_start (varargs_list, fmt_string);

   va_copy (varargs_copy, varargs_list);

   extra_size = vsnprintf (NULL, 0, fmt_string, varargs_list);

   va_end (varargs_list); // release the variable arguments list

   // now, reallocate space to hold extra_size bytes more

   reallocated_ptr = realloc (buffer->bytes, buffer->size + extra_size + sizeof (size_t)); // always null-terminate buffers, but never report the null terminator

   if (reallocated_ptr == NULL)

   {

      if (saved_locale != NULL)

      {

         setlocale (LC_ALL, saved_locale); // restore user locale

         free (saved_locale); // and free the memory we used to back it up

      }

      return (0); // on failure, return an error value (errno already set to ENOMEM)

   }

   buffer->bytes = reallocated_ptr; // save pointer to reallocated data

   if (extra_size > 0)

   {

      vsnprintf ((char *) &buffer->bytes[buffer->size], extra_size + 1, fmt_string, varargs_copy); // write new data at the end

      buffer->size += extra_size; // and increment buffer size

   }

   va_end (varargs_copy); // release the variable arguments list

   for (padding = 0; padding < sizeof (size_t); padding++)

      buffer->bytes[buffer->size + padding] = 0; // always null-terminate buffers, silently

   if (saved_locale != NULL)

   {

      setlocale (LC_ALL, saved_locale); // restore user locale

      free (saved_locale); // and free the memory we used to back it up

   }

   return (1); // buffer appended successfully, return SUCCESS

}

int Buffer_Prepend (buffer_t *buffer, const void *data, const size_t data_size)

{

   // this function prepends the contents of data to a buffer's data.

   // Returns 1 on success, 0 on error (in which case errno is set to ENOMEM).

   void *reallocated_ptr;

   size_t padding;

   // first, reallocate space to hold data_size bytes more

   reallocated_ptr = realloc (buffer->bytes, data_size + buffer->size + sizeof (size_t)); // always null-terminate buffers, but never report the null terminator

   if (reallocated_ptr == NULL)

      return (0); // on failure, return an error value (errno already set to ENOMEM)

   buffer->bytes = reallocated_ptr; // save pointer to reallocated data

   if (data_size > 0)

   {

#ifdef _MSC_VER

#pragma warning(push)

#pragma warning(disable:6385) // the Microsoft linter is wrong here.

#pragma warning(disable:6386)

#endif // _MSC_VER

      if (buffer->size > 0)

         memmove (&buffer->bytes[data_size], buffer->bytes, buffer->size); // move existing data to the end

      memcpy (buffer->bytes, data, data_size); // write new data at the beginning

#ifdef _MSC_VER

#pragma warning(pop)

#endif // _MSC_VER

      buffer->size += data_size; // and increment buffer size

   }

   for (padding = 0; padding < sizeof (size_t); padding++)

      buffer->bytes[buffer->size + padding] = 0; // always null-terminate buffers, silently

   return (1); // buffer appended successfully, return SUCCESS

}

int Buffer_PrependFormattedCString (buffer_t *buffer, const char *fmt_string, ...)

{

   // this function prepends some printf-style formatted data to a buffer's data.

   // Buffer is always null-terminated, but the terminator is NOT counted in the buffer's length.

   // Returns 1 on success, 0 on error (in which case errno is set to either ENOMEM, EILSEQ or EINVAL).

   void *reallocated_ptr;

   va_list varargs_list;

   va_list varargs_copy;

   uint8_t first_byte;

   char *saved_locale;

   int extra_size;

   size_t padding;

   saved_locale = setlocale (LC_ALL, NULL); // get the current locale

   if (saved_locale != NULL)

      saved_locale = strdup (saved_locale); // preserve it

   setlocale (LC_ALL, "C"); // format everything in the POSIX (international) locale

   // first, concatenate varargs and see how much extra space we need

   va_start (varargs_list, fmt_string);

   va_copy (varargs_copy, varargs_list);

   extra_size = vsnprintf (NULL, 0, fmt_string, varargs_list);

   va_end (varargs_list); // release the variable arguments list

   // was there an encoding error ?

   if (extra_size < 0)

   {

      if (saved_locale != NULL)

      {

         setlocale (LC_ALL, saved_locale); // restore user locale

         free (saved_locale); // and free the memory we used to back it up

      }

      return (0); // on failure, return an error value (errno already set to either EILSEQ or EINVAL)

   }

   // now, reallocate space to hold extra_size bytes more

   reallocated_ptr = realloc (buffer->bytes, buffer->size + extra_size + sizeof (size_t)); // always null-terminate buffers, but never report the null terminator

   if (reallocated_ptr == NULL)

   {

      if (saved_locale != NULL)

      {

         setlocale (LC_ALL, saved_locale); // restore user locale

         free (saved_locale); // and free the memory we used to back it up

      }

      return (0); // on failure, return an error value (errno already set to ENOMEM)

   }

   buffer->bytes = reallocated_ptr; // save pointer to reallocated data

   if (extra_size > 0)

   {

#ifdef _MSC_VER

#pragma warning(push)

#pragma warning(disable:6001) // the Microsoft linter is wrong here.

#pragma warning(disable:6385)

#pragma warning(disable:6386)

#endif // _MSC_VER

      if (buffer->size > 0)

      {

         first_byte = buffer->bytes[0]; // remember what the first byte is, since vsnprintf() will overwrite it with a null terminator

         memmove (&buffer->bytes[extra_size], buffer->bytes, buffer->size); // move existing data to the end

      }

      vsnprintf ((char *) buffer->bytes, (size_t) extra_size + 1, fmt_string, varargs_copy); // write new data at the start (overwriting the first character of the old string with the null terminator)

#ifdef _MSC_VER

#pragma warning(pop)

#endif // _MSC_VER

      if (buffer->size > 0)

         buffer->bytes[extra_size] = first_byte; // put back the old first char, which was overwriten by vsnprintf()

      buffer->size += extra_size; // and increment buffer size

   }

   va_end (varargs_copy); // release the variable arguments list

   for (padding = 0; padding < sizeof (size_t); padding++)

      buffer->bytes[buffer->size + padding] = 0; // always null-terminate buffers, silently

   if (saved_locale != NULL)

   {

      setlocale (LC_ALL, saved_locale); // restore user locale

      free (saved_locale); // and free the memory we used to back it up

   }

   return (1); // buffer appended successfully, return SUCCESS

}

int Buffer_InsertAt (buffer_t *buffer, const size_t insert_index, const void *data, const size_t data_size)

{

   // this function inserts the contents of data to a buffer's data at position insert_index,

   // shifting the remaining data from insert_index data_size forward.

   // Returns 1 on success, 0 on error (in which case errno is set to ENOMEM).

   void *reallocated_ptr;

   size_t padding;

   // reallocate data buffer at the right size

   reallocated_ptr = realloc (buffer->bytes, buffer->size + data_size + sizeof (size_t)); // always null-terminate buffers, but never report the null terminator

   if (reallocated_ptr == NULL)

      return (0); // on failure, return an error value (errno already set to ENOMEM)

   buffer->bytes = reallocated_ptr; // save pointer to reallocated data

   if (insert_index > buffer->size)

      memset (&buffer->bytes[buffer->size], 0, insert_index - buffer->size); // buffer was upsized: fill the upsized part with zeroes up to insert_index

   if (data_size > 0)

   {

      memmove (&buffer->bytes[insert_index + data_size], &buffer->bytes[insert_index], buffer->size - insert_index); // move existing data to the end

      memcpy (&buffer->bytes[insert_index], data, data_size); // write data in place

      buffer->size += data_size; // update data size

   }

   for (padding = 0; padding < sizeof (size_t); padding++)

      buffer->bytes[buffer->size + padding] = 0; // always null-terminate buffers, silently

   return (1); // data successfully inserted into buffer, return SUCCESS

}

int Buffer_WriteAt (buffer_t *buffer, const size_t write_index, const void *data, const size_t data_size)

{

   // this function writes the contents of data to a buffer's data at position write_index, expanding the buffer if necessary.

   // Returns 1 on success, 0 on error (in which case errno is set to ENOMEM).

   void *reallocated_ptr;

   size_t padding;

   // see if we need to grow the data

   if (write_index + data_size > buffer->size)

   {

      // if so, reallocate data buffer at the right size

      reallocated_ptr = realloc (buffer->bytes, write_index + data_size + sizeof (size_t)); // always null-terminate buffers, but never report the null terminator

      if (reallocated_ptr == NULL)

         return (0); // on failure, return an error value (errno already set to ENOMEM)

      buffer->bytes = reallocated_ptr; // save pointer to reallocated data

      memset (&buffer->bytes[buffer->size], 0, write_index - buffer->size); // buffer was upsized: fill the upsized part with zeroes up to write_index

   }

   if (data_size > 0)

      memcpy (&buffer->bytes[write_index], data, data_size); // write data in place

   if (write_index + data_size > buffer->size)

      buffer->size = write_index + data_size; // update data size only if it growed

   else

   {

      // IMPORTANT: data hasn't growed, BUT the passed buffer *MIGHT NOT* have the \0\0\0\0 suffix (e.g. hand-constructed), so we MUST ensure there's space in it to put it!

      // reallocate data buffer at the right size

      reallocated_ptr = realloc (buffer->bytes, buffer->size + sizeof (size_t)); // always null-terminate buffers, but never report the null terminator

      if (reallocated_ptr == NULL)

         return (0); // on failure, return an error value (errno already set to ENOMEM)

      buffer->bytes = reallocated_ptr; // save pointer to reallocated data

   }

   for (padding = 0; padding < sizeof (size_t); padding++)

      buffer->bytes[buffer->size + padding] = 0; // always null-terminate buffers, silently

   return (1); // buffer written successfully, return SUCCESS

}

int Buffer_SubsetFromTo (buffer_t *buffer, const size_t from_index, const size_t to_index)

{

   // this function shortens the passed buffer by transforming it into its subset ranging

   // from from_index (0 meaning beginning of buffer) to to_index (0 *NOT* meaning end of buffer!!! FIXME),

   // shortening the buffer as necessary.

   // Returns 1 on success, 0 on error (in which case errno is set to E2BIG).

   void *reallocated_ptr;

   size_t padding;

   if ((from_index > to_index) || (to_index > buffer->size))

   {

      errno = E2BIG; // set errno to a significant value

      return (0); // consistency check: return FAILURE if we're requesting an out of bounds subset

   }

   buffer->size = to_index - from_index; // report the new buffer size

   // should we shift the data ?

   if (from_index > 0)

      memmove (buffer->bytes, &buffer->bytes[from_index], buffer->size); // shift everything if necessary

   // IMPORTANT: the passed buffer *MIGHT NOT* have the \0\0\0\0 suffix (e.g. hand-constructed), so we MUST ensure there's space in it to put it!

   // reallocate data buffer at the right size

   reallocated_ptr = realloc (buffer->bytes, buffer->size + sizeof (size_t)); // always null-terminate buffers, but never report the null terminator

   if (reallocated_ptr == NULL)

      return (0); // on failure, return an error value (errno is set)

   buffer->bytes = reallocated_ptr; // save pointer to reallocated data

   for (padding = 0; padding < sizeof (size_t); padding++)

      buffer->bytes[buffer->size + padding] = 0; // always null-terminate buffers, silently

   return (1); // buffer subset isolated successfully, return SUCCESS

}

int Buffer_ReadFromFile (buffer_t *buffer, const char *file_pathname)

{

   // this function copies the contents of file_pathname in a newly allocated data buffer

   // and fills in the buffer size accordingly. It is up to the caller to free that buffer.

   // Returns 1 on success, 0 on error (in which case errno is set to either EACCESS, ENOMEM or EIO or anything else set by the underlying buffered stream API).

   void *allocated_ptr;

   int errno_backup;

   size_t filesize;

   size_t padding;

   FILE *fp; // buffered I/O with FILE * is ___FASTER___ than unbuffered I/O with file descriptors

   // start by reporting a zero length

   buffer->bytes = NULL;

   buffer->size = 0;

   // open file for binary reading (DO NOT stat() BEFORE, ELSE WE WOULD NEED TO APPLY THE SAME LONG PATHNAME WORKAROUND TWICE)

#if defined(_WIN32) && (!defined(MAXPATHLEN) || (MAXPATHLEN <= 260))

   // on Windows, work around of the MAX_PATH limitation by using the Unicode APIs and NT-style pathnames

   // IMPLEMENTATION NOTE: ON WINDOWS, ALL PATHS ARE CONVERTED TO UTF-16 IN MSVCRT.DLL BEFORE THE ACTUAL SYSTEM CALL,

   // SO IT *IS* FASTER TO SYSTEMATICALLY CONVERT ALL PATHS TO NT PATHS, LIKE THEY DO IN LLVM/CLANG (see Path.inc)

   errno = EACCES; // set errno to something significant

   fp = NULL; // assume failure until told otherwise

   MultiByteToWideChar (AreFileApisANSI () ? 0 /*CP_ACP*/ : 1 /*CP_OEMCP*/, 0, file_pathname, -1, wide_pathname, sizeof (wide_pathname) / sizeof (wchar_t)); // convert pathname to wide characters, including the NULL terminator

   GetFullPathNameW (wide_pathname, sizeof (nt_pathname) / sizeof (wchar_t) - 4, &nt_pathname[4], NULL); // canonicalize the resulting pathname and write it just after the NT path prefix

   nt_filehandle = CreateFileW (nt_pathname, 0x80000000 /*GENERIC_READ*/, 0x3 /*FILE_SHARE_READ|FILE_SHARE_WRITE*/, NULL, 3 /*OPEN_EXISTING*/, 0x80 /*FILE_ATTRIBUTE_NORMAL*/, NULL); // now call CreateFile and get the filesystem object handle

   if (nt_filehandle != NULL)

   {

      intermediary_fd = _open_osfhandle ((intptr_t) nt_filehandle, O_RDONLY); // and convert this handle back into a POSIX file descriptor

      if (intermediary_fd != -1)

      {

         fp = _fdopen (intermediary_fd, "rb"); // now convert this handle to a buffered libc file descriptor

         if (fp == NULL)

            _close (intermediary_fd); // if we couldn't get a libc file descriptor out of that POSIX file descriptor, close it anyway

      }

      else

         CloseHandle (nt_filehandle); // if we couldn't get a POSIX file descriptor out of that handle, close it anyway

   }

   if (fp != NULL)

      errno = 0; // if file could be opened, clear errno

#else // !defined(_WIN32) || (defined(MAXPATHLEN) && (MAXPATHLEN > 260))

   fp = fopen (file_pathname, "rb"); // POSIX-compliant system. Good boy.

#endif // defined(_WIN32) && (!defined(MAXPATHLEN) || (MAXPATHLEN <= 260))

   if (fp == NULL)

      return (0); // on fopen() failure, return an error value (and errno is hopefully set to something meaningful)

   // measure file size

   fseek (fp, 0, SEEK_END);

   filesize = ftell (fp);

   fseek (fp, 0, SEEK_SET);

   // allocate enough space for it

   allocated_ptr = malloc (filesize + sizeof (size_t)); // always null-terminate buffers, but never report the null terminator

   if (allocated_ptr == NULL)

   {

      errno_backup = errno; // preserve errno on errors

      fclose (fp); // on malloc() error, close file

      errno = errno_backup;

      return (0); // and return an error value (errno already set to ENOMEM)

   }

   buffer->bytes = allocated_ptr; // save pointer to newly allocated data

   // and read it at once

   if (fread (buffer->bytes, 1, filesize, fp) != filesize)

   {

      errno_backup = (errno ? errno : EIO); // preserve errno on errors; if it isn't set, set it to EIO

      fclose (fp); // fread() failed, close file

      free (buffer->bytes);

      errno = errno_backup;

      return (0); // on failure, return an error value (errno already set to EIO - or something else set by the underlying buffered stream API)

   }

   fclose (fp); // finished, close file

   buffer->size = filesize; // report its size

   for (padding = 0; padding < sizeof (size_t); padding++)

      buffer->bytes[buffer->size + padding] = 0; // always null-terminate buffers, silently

   return (1); // and return SUCCESS

}

int Buffer_WriteToFile (buffer_t *buffer, const char *file_pathname)

{

   // this function copies the contents of buffer's data into the file pointed to by

   // file_pathname. Returns 1 on success, 0 on error (in which case errno is set to either EINVAL, ENOMEM, EACCESS or EIO or anything else set by the underlying buffered stream API).

   // NOTE: "<stdout>" and "<stderr>" pathnames can be used to write to stdout and stderr,

   // else all directories up to file_pathname are recursively created if necessary.

   size_t string_index;

   size_t length;

   int errno_backup;

   char *temp_pathname;

   char *separator;

   char *context;

   FILE *fp; // buffered I/O with FILE * is ___FASTER___ than unbuffered I/O with file descriptors

   // do we want to write to the standard output or the standard error?

   if (strcmp (file_pathname, "<stdout>") == 0)

      fp = stdout;

   else if (strcmp (file_pathname, "<stderr>") == 0)

      fp = stderr;

   else

   {

      // ensure all the path up to file exists, create directories on the fly if needed

      // FIXME: this won't work on Windows with symlinks pointing to nonexistent directories...

      length = strlen (file_pathname);

      if (length == 0)

      {

         errno = EINVAL; // if the passed pathname is empty, report invalid parameter

         return (0); // and return an error value

      }

      temp_pathname = strdup (file_pathname); // have a working copy of file_pathname

      if (temp_pathname == NULL)

         return (0); // on strdup() failure, return an error value (errno already set to ENOMEM)

      for (string_index = length - 1; string_index != SIZE_MAX; string_index--) // i.e. loop until it overflows

         if ((temp_pathname[string_index] == '/') || (temp_pathname[string_index] == '\\'))

            break; // look for the last directory separator and stop as soon as we find it

      if (string_index != SIZE_MAX)

      {

         for (; string_index < length; string_index++)

            temp_pathname[string_index] = 0; // if we found one, break there so as to have just the path and clear the rest of the string

         context = NULL;

         separator = strtok_r (&temp_pathname[1], "/\\", &context); // for each separator in the remaining string past the first one...

         while (separator != NULL)

         {

            (void) mkdir (temp_pathname, 0755); // create directories recursively (FIXME: THIS IS NOT COMPATIBLE WITH LONG FILENAMES)

            temp_pathname[strlen (temp_pathname)] = '/'; // put back the separator

            separator = strtok_r (NULL, "/\\", &context); // and look for the next one

         }

      }

      free (temp_pathname); // release our working copy of file_pathname

      // open file for binary writing

#if defined(_WIN32) && (!defined(MAXPATHLEN) || (MAXPATHLEN <= 260))

      // on Windows, work around of the MAX_PATH limitation by using the Unicode APIs and NT-style pathnames

      // IMPLEMENTATION NOTE: ON WINDOWS, ALL PATHS ARE CONVERTED TO UTF-16 IN MSVCRT.DLL BEFORE THE ACTUAL SYSTEM CALL,

      // SO IT *IS* FASTER TO SYSTEMATICALLY CONVERT ALL PATHS TO NT PATHS, LIKE THEY DO IN LLVM/CLANG (see Path.inc)

      errno = EACCES; // set errno to something significant

      fp = NULL; // assume failure until told otherwise

      MultiByteToWideChar (AreFileApisANSI () ? 0 /*CP_ACP*/ : 1 /*CP_OEMCP*/, 0, file_pathname, -1, wide_pathname, sizeof (wide_pathname) / sizeof (wchar_t)); // convert pathname to wide characters, including the NULL terminator

      GetFullPathNameW (wide_pathname, sizeof (nt_pathname) / sizeof (wchar_t) - 4, &nt_pathname[4], NULL); // canonicalize the resulting pathname and write it just after the NT path prefix

      nt_filehandle = CreateFileW (nt_pathname, 0x40000000 /*GENERIC_WRITE*/, 0x3 /*FILE_SHARE_READ|FILE_SHARE_WRITE*/, NULL, 2 /*CREATE_ALWAYS [MANDATORY for truncation!]*/, 0x80 /*FILE_ATTRIBUTE_NORMAL*/, NULL); // now call CreateFile and get the filesystem object handle

      if (nt_filehandle != NULL)

      {

         intermediary_fd = _open_osfhandle ((intptr_t) nt_filehandle, O_WRONLY); // and convert this handle back into a POSIX file descriptor

         if (intermediary_fd != -1)

         {

            fp = _fdopen (intermediary_fd, "wb"); // now convert this handle to a buffered libc file descriptor

            if (fp == NULL)

               _close (intermediary_fd); // if we couldn't get a libc file descriptor out of that POSIX file descriptor, close it anyway

         }

         else

            CloseHandle (nt_filehandle); // if we couldn't get a POSIX file descriptor out of that handle, close it anyway

      }

      if (fp != NULL)

         errno = 0; // if file could be opened, clear errno

#else // !defined(_WIN32) || (defined(MAXPATHLEN) && (MAXPATHLEN > 260))

      fp = fopen (file_pathname, "wb"); // POSIX-compliant system. Good boy.

#endif // defined(_WIN32) && (!defined(MAXPATHLEN) || (MAXPATHLEN <= 260))

      if (fp == NULL)

         return (0); // on fopen() failure, return an error value (and errno is hopefully set to something meaningful)

   }

   // and write it at once

   if (fwrite (buffer->bytes, 1, buffer->size, fp) != buffer->size)

   {

      errno_backup = (errno ? errno : EIO); // preserve errno on errors; if it isn't set, set it to EIO

      if ((fp != stdout) && (fp != stderr))

         fclose (fp); // either case, close the file

      errno = errno_backup;

      return (0); // on failure, return an error value (errno already set to EIO - or something else set by the underlying buffered stream API)

   }

   if ((fp != stdout) && (fp != stderr))

      fclose (fp); // finished, close file (only if it was not one of the standard streams)

   errno = 0; // no error

   return (1); // and return SUCCESS

}

uint8_t *Buffer_FindFirst (const buffer_t *buffer, const void *needle, const size_t needle_length)

{

   // returns a pointer to the first occurence of needle in buffer haystack, or NULL if not found

   size_t byte_index;

   if (buffer->size < needle_length)

      return (NULL); // consistency check: if buffer is too small for needle, return NULL

   else if ((buffer->size == needle_length) && (memcmp (buffer->bytes, needle, buffer->size) == 0))

      return (buffer->bytes); // special case where needle is exactly as long as buffer

   // parse buffer from start to end

   for (byte_index = 0; byte_index <= buffer->size - needle_length; byte_index++) // inferior OR EQUAL, meaning last position INCLUDED!

      if (memcmp (&buffer->bytes[byte_index], needle, needle_length) == 0)

         return (&buffer->bytes[byte_index]); // return the first match we find

   return (NULL); // definitely no needle in buffer

}

uint8_t *Buffer_FindFirstCI (const buffer_t *buffer, const char *needle)

{

   // returns a pointer to the first occurence of needle in buffer haystack (CASE INSENSITIVELY), or NULL if not found

   size_t needle_length;

   size_t byte_index;

   needle_length = strlen (needle); // measure needle length

   if (buffer->size < needle_length)

      return (NULL); // consistency check: if buffer is too small for needle, return NULL

   else if ((buffer->size == needle_length) && (memcmp (buffer->bytes, needle, buffer->size) == 0))

      return (buffer->bytes); // special case where needle is exactly as long as buffer

   // parse buffer from start to end

   for (byte_index = 0; byte_index <= buffer->size - needle_length; byte_index++) // inferior OR EQUAL, meaning last position INCLUDED!

      if (strncasecmp ((const char *) &buffer->bytes[byte_index], needle, needle_length) == 0)

         return (&buffer->bytes[byte_index]); // return the first match we find

   return (NULL); // definitely no needle in buffer

}

uint8_t *Buffer_FindLast (const buffer_t *buffer, const void *needle, const size_t needle_length)

{

   // returns a pointer to the last occurence of needle in buffer haystack, or NULL if not found

   size_t byte_index;

   if (buffer->size < needle_length)

      return (NULL); // consistency check: if buffer is too small for needle, return NULL

   else if ((buffer->size == needle_length) && (memcmp (buffer->bytes, needle, buffer->size) == 0))

      return (buffer->bytes); // special case where needle is exactly as long as buffer

   // parse buffer from end to start

   for (byte_index = buffer->size - needle_length; byte_index != SIZE_MAX; byte_index--)

      if (memcmp (&buffer->bytes[byte_index], needle, needle_length) == 0)

         return (&buffer->bytes[byte_index]); // return the last match we find

   return (NULL); // definitely no needle in buffer

}

uint8_t *Buffer_FindLastCI (const buffer_t *buffer, const char *needle)

{

   // returns a pointer to the last occurence of needle in buffer haystack (CASE INSENSITIVELY), or NULL if not found

   size_t needle_length;

   size_t byte_index;

   needle_length = strlen (needle); // measure needle length

   if (buffer->size < needle_length)

      return (NULL); // consistency check: if buffer is too small for needle, return NULL

   else if ((buffer->size == needle_length) && (memcmp (buffer->bytes, needle, buffer->size) == 0))

      return (buffer->bytes); // special case where needle is exactly as long as buffer

   // parse buffer from end to start

   for (byte_index = buffer->size - needle_length; byte_index != SIZE_MAX; byte_index--)

      if (strncasecmp ((const char *) &buffer->bytes[byte_index], needle, needle_length) == 0)

         return (&buffer->bytes[byte_index]); // return the last match we find

   return (NULL); // definitely no needle in buffer

}

size_t Buffer_Replace (buffer_t *buffer, const void *needle, const size_t needle_length, const void *replacement, const size_t replacement_length, const int howmany_with_zero_for_all_and_minus_for_backwards)

{

   // replaces as many occurences of needle with replacement in buffer haystack, reallocating as needed.

   // If howmany is strictly positive, replacements stop after howmany replacements are made in the forward direction.

   // If howmany is strictly negative, replacements stop after -howmany replacements are made in the REVERSE direction.

   // Returns the number of replacements made, or 0 if none was made OR an error occured (in which case check errno, which may be E2BIG or ENOMEM).

   void *reallocated_ptr;

   void *safe_needle;

   size_t replacements_made;

   size_t replacements_max;

   size_t byte_index;

   size_t padding;

   int realloc_done;

   if (needle_length > buffer->size)

   {

      errno = E2BIG; // consistency check: if buffer is too small for needle, set errno to E2BIG

      return (0); // and return an error value

   }

   if (needle_length == 0)

      return (0); // consistency check: if needle is an empty string, return 0 (no replacement made)

   // is the number of replacements to do NOT exactly one AND does the needle we want to replace already belong to the buffer (meaning it will disappear during replacement) ?

   if ((abs (howmany_with_zero_for_all_and_minus_for_backwards) != 1) && ((uint8_t *) needle > buffer->bytes) && ((uint8_t *) needle < buffer->bytes + buffer->size))

   {

      safe_needle = (uint8_t *) malloc (needle_length); // allocate space for a copy of the needle

      if (safe_needle == NULL)

         return (0); // on allocation error, return 0 (errno already set to ENOMEM)

      memcpy (safe_needle, needle, needle_length); // and copy needle somewhere safe

   }

   else

      safe_needle = (uint8_t *) needle; // else we can use needle directly and spare us an allocation

   // see how much we need to replace and in what order

   replacements_made = 0;

   realloc_done = 0;

   if (howmany_with_zero_for_all_and_minus_for_backwards < 0)

   {

      // backwards direction

      replacements_max = -howmany_with_zero_for_all_and_minus_for_backwards;

      // parse buffer from end to start

      for (byte_index = buffer->size - needle_length; byte_index != SIZE_MAX; byte_index--)

      {

         if (memcmp (&buffer->bytes[byte_index], safe_needle, needle_length) != 0)

            continue; // if there's no match at this location, skip it

         // a replacement should be made here: see if we need to grow the data

         if (replacement_length > needle_length)

         {

            // if so, reallocate data buffer at the right size

            reallocated_ptr = realloc (buffer->bytes, buffer->size + replacement_length - needle_length + sizeof (size_t)); // always null-terminate buffers, but never report the null terminator

            if (reallocated_ptr == NULL)

            {