string.c

Go to the documentation of this file.

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%                  SSSSS   TTTTT  RRRR   IIIII  N   N   GGGG                  %
%                  SS        T    R   R    I    NN  N  G                      %
%                   SSS      T    RRRR     I    N N N  G GGG                  %
%                     SS     T    R R      I    N  NN  G   G                  %
%                  SSSSS     T    R  R   IIIII  N   N   GGGG                  %
%                                                                             %
%                                                                             %
%                        MagickCore String Methods                            %
%                                                                             %
%                             Software Design                                 %
%                               John Cristy                                   %
%                               August 2003                                   %
%                                                                             %
%                                                                             %
%  Copyright 1999-2008 ImageMagick Studio LLC, a non-profit organization      %
%  dedicated to making software imaging solutions freely available.           %
%                                                                             %
%  You may not use this file except in compliance with the License.  You may  %
%  obtain a copy of the License at                                            %
%                                                                             %
%    http://www.imagemagick.org/script/license.php                            %
%                                                                             %
%  Unless required by applicable law or agreed to in writing, software        %
%  distributed under the License is distributed on an "AS IS" BASIS,          %
%  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   %
%  See the License for the specific language governing permissions and        %
%  limitations under the License.                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%
*/

/*
  Include declarations.
*/
#include "magick/studio.h"
#include "magick/blob.h"
#include "magick/blob-private.h"
#include "magick/exception.h"
#include "magick/exception-private.h"
#include "magick/list.h"
#include "magick/log.h"
#include "magick/memory_.h"
#include "magick/property.h"
#include "magick/resource_.h"
#include "magick/signature-private.h"
#include "magick/string_.h"

/*
  Static declarations.
*/
#if !defined(MAGICKCORE_HAVE_STRCASECMP) || !defined(MAGICKCORE_HAVE_STRNCASECMP)
static const unsigned char
  AsciiMap[] =
  {
    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b,
    0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
    0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23,
    0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
    0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b,
    0x3c, 0x3d, 0x3e, 0x3f, 0x40, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
    0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73,
    0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
    0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b,
    0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
    0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83,
    0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
    0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b,
    0x9c, 0x9d, 0x9e, 0x9f, 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
    0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, 0xb0, 0xb1, 0xb2, 0xb3,
    0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
    0xc0, 0xe1, 0xe2, 0xe3, 0xe4, 0xc5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb,
    0xec, 0xed, 0xee, 0xef, 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
    0xf8, 0xf9, 0xfa, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, 0xe0, 0xe1, 0xe2, 0xe3,
    0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
    0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb,
    0xfc, 0xfd, 0xfe, 0xff,
  };
#endif

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   A c q u i r e S t r i n g                                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  AcquireString() allocates memory for a string and copies the source string
%  to that memory location (and returns it).
%
%  The format of the AcquireString method is:
%
%      char *AcquireString(const char *source)
%
%  A description of each parameter follows:
%
%    o source: A character string.
%
*/
MagickExport char *AcquireString(const char *source)
{
  char
    *destination;

  size_t
    length;

  length=0;
  if (source != (char *) NULL)
    length+=strlen(source);
  destination=(char *) NULL;
  if (~length >= MaxTextExtent)
    destination=(char *) AcquireQuantumMemory(length+MaxTextExtent,
      sizeof(*destination));
  if (destination == (char *) NULL)
    ThrowFatalException(ResourceLimitFatalError,"UnableToAcquireString");
  *destination='\0';
  if (source != (char *) NULL)
    (void) CopyMagickString(destination,source,(length+1)*sizeof(*destination));
  return(destination);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   A c q u i r e S t r i n g I n f o                                         %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  AcquireStringInfo() allocates the StringInfo structure.
%
%  The format of the AcquireStringInfo method is:
%
%      StringInfo *AcquireStringInfo(const size_t length)
%
%  A description of each parameter follows:
%
%    o length: the string length.
%
*/
MagickExport StringInfo *AcquireStringInfo(const size_t length)
{
  StringInfo
    *string_info;

  string_info=(StringInfo *) AcquireMagickMemory(sizeof(*string_info));
  if (string_info == (StringInfo *) NULL)
    ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
  (void) ResetMagickMemory(string_info,0,sizeof(*string_info));
  string_info->signature=MagickSignature;
  string_info->length=length;
  if (string_info->length != 0)
    {
      string_info->datum=(unsigned char *) NULL;
      if (~string_info->length >= MaxTextExtent)
        string_info->datum=(unsigned char *) AcquireQuantumMemory(
          string_info->length+MaxTextExtent,sizeof(*string_info->datum));
      if (string_info->datum == (unsigned char *) NULL)
        ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
    }
  return(string_info);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   C l o n e S t r i n g                                                     %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  CloneString() allocates memory for the destination string and copies
%  the source string to that memory location.
%
%  The format of the CloneString method is:
%
%      char *CloneString(char **destination,const char *source)
%
%  A description of each parameter follows:
%
%    o destination:  A pointer to a character string.
%
%    o source: A character string.
%
*/
MagickExport char *CloneString(char **destination,const char *source)
{
  size_t
    length;

  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
  assert(destination != (char **) NULL);
  if (source == (const char *) NULL)
    {
      if (*destination != (char *) NULL)
        *destination=DestroyString(*destination);
      return(*destination);
    }
  if (*destination == (char *) NULL)
    {
      *destination=AcquireString(source);
      return(*destination);
    }
  length=strlen(source);
  if (~length < MaxTextExtent)
    ThrowFatalException(ResourceLimitFatalError,"UnableToAcquireString");
  *destination=(char *) ResizeQuantumMemory(*destination,length+MaxTextExtent,
    sizeof(*destination));
  if (*destination == (char *) NULL)
    ThrowFatalException(ResourceLimitFatalError,"UnableToAcquireString");
  (void) CopyMagickString(*destination,source,(length+1)*sizeof(*destination));
  return(*destination);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   C l o n e S t r i n g I n f o                                             %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  CloneStringInfo() clones a copy of the StringInfo structure.
%
%  The format of the CloneStringInfo method is:
%
%      StringInfo *CloneStringInfo(const StringInfo *string_info)
%
%  A description of each parameter follows:
%
%    o string_info: the string info.
%
*/
MagickExport StringInfo *CloneStringInfo(const StringInfo *string_info)
{
  StringInfo
    *clone_info;

  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
  assert(string_info != (StringInfo *) NULL);
  assert(string_info->signature == MagickSignature);
  clone_info=AcquireStringInfo(string_info->length);
  if (string_info->length != 0)
    (void) CopyMagickMemory(clone_info->datum,string_info->datum,
      string_info->length+1);
  return(clone_info);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   C o m p a r e S t r i n g I n f o                                         %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  CompareStringInfo() compares the two datums target and source.  It returns
%  an integer less than, equal to, or greater than zero if target is found,
%  respectively, to be less than, to match, or be greater than source.
%
%  The format of the CompareStringInfo method is:
%
%      int CompareStringInfo(const StringInfo *target,const StringInfo *source)
%
%  A description of each parameter follows:
%
%    o target: the target string.
%
%    o source: the source string.
%
*/

static inline size_t MagickMin(const size_t x,const size_t y)
{
  if (x < y)
    return(x);
  return(y);
}

MagickExport int CompareStringInfo(const StringInfo *target,
  const StringInfo *source)
{
  int
    status;

  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
  assert(target != (StringInfo *) NULL);
  assert(target->signature == MagickSignature);
  assert(source != (StringInfo *) NULL);
  assert(source->signature == MagickSignature);
  status=memcmp(target->datum,source->datum,MagickMin(target->length,
    source->length));
  if (status != 0)
    return(status);
  if (target->length == source->length)
    return(0);
  return(target->length < source->length ? -1 : 1);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   C o n c a t e n a t e M a g i c k S t r i n g                             %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  ConcatenateMagickString() concatenates the source string to the destination
%  string.  The destination buffer is always null-terminated even if the
%  string must be truncated.
%
%  The format of the ConcatenateMagickString method is:
%
%      size_t ConcatenateMagickString(char *destination,const char *source,
%        const size_t length)
%
%  A description of each parameter follows:
%
%    o destination: the destination string.
%
%    o source: the source string.
%
%    o length: the length of the destination string.
%
*/
MagickExport size_t ConcatenateMagickString(char *destination,
  const char *source,const size_t length)
{
  register char
    *q;

  register const char
    *p;

  register size_t
    i;

  size_t
    count;

  assert(destination != (char *) NULL);
  assert(source != (const char *) NULL);
  assert(length >= 1);
  p=source;
  q=destination;
  i=length;
  while ((i-- != 0) && (*q != '\0'))
    q++;
  count=(size_t) (q-destination);
  i=length-count;
  if (i == 0)
    return(count+strlen(p));
  while (*p != '\0')
  {
    if (i != 1)
      {
        *q++=(*p);
        i--;
      }
    p++;
  }
  *q='\0';
  return(count+(p-source));
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   C o n c a t e n a t e S t r i n g                                         %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  ConcatenateString() appends a copy of string source, including the
%  terminating null character, to the end of string destination.
%
%  The format of the ConcatenateString method is:
%
%      MagickBooleanType ConcatenateString(char **destination,
%        const char *source)
%
%  A description of each parameter follows:
%
%    o destination:  A pointer to a character string.
%
%    o source: A character string.
%
*/
MagickExport MagickBooleanType ConcatenateString(char **destination,
  const char *source)
{
  size_t
    length,
    source_length;

  assert(destination != (char **) NULL);
  if (source == (const char *) NULL)
    return(MagickTrue);
  if (*destination == (char *) NULL)
    {
      *destination=AcquireString(source);
      return(MagickTrue);
    }
  length=strlen(*destination);
  source_length=strlen(source);
  if (~length < source_length)
    ThrowFatalException(ResourceLimitFatalError,"UnableToConcatenateString");
  length+=source_length;
  if (~length < MaxTextExtent)
    ThrowFatalException(ResourceLimitFatalError,"UnableToConcatenateString");
  *destination=(char *) ResizeQuantumMemory(*destination,length+MaxTextExtent,
    sizeof(*destination));
  if (*destination == (char *) NULL)
    ThrowFatalException(ResourceLimitFatalError,"UnableToConcatenateString");
  (void) ConcatenateMagickString(*destination,source,(length+1)*
    sizeof(*destination));
  return(MagickTrue);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   C o n c a t e n a t e S t r i n g I n f o                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  ConcatenateStringInfo() concatenates the source string to the destination
%  string.
%
%  The format of the ConcatenateStringInfo method is:
%
%      void ConcatenateStringInfo(StringInfo *string_info,
%        const StringInfo *source)
%
%  A description of each parameter follows:
%
%    o string_info: the string info.
%
%    o source: the source string.
%
*/
MagickExport void ConcatenateStringInfo(StringInfo *string_info,
  const StringInfo *source)
{
  size_t
    length;

  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
  assert(string_info != (StringInfo *) NULL);
  assert(string_info->signature == MagickSignature);
  assert(source != (const StringInfo *) NULL);
  length=string_info->length;
  if (~length < source->length)
    ThrowFatalException(ResourceLimitFatalError,"UnableToConcatenateString");
  SetStringInfoLength(string_info,length+source->length);
  (void) CopyMagickMemory(string_info->datum+length,source->datum,
    source->length);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   C o n f i g u r e F i l e T o S t r i n g I n f o                         %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  ConfigureFileToStringInfo() returns the contents of a configure file as a
%  string.
%
%  The format of the ConfigureFileToStringInfo method is:
%
%      StringInfo *ConfigureFileToStringInfo(const char *filename)
%        ExceptionInfo *exception)
%
%  A description of each parameter follows:
%
%    o filename: the filename.
%
*/
MagickExport StringInfo *ConfigureFileToStringInfo(const char *filename)
{
  char
    *string;

  int
    file;

  MagickOffsetType
    offset;

  size_t
    length;

  StringInfo
    *string_info;

  void
    *map;

  assert(filename != (const char *) NULL);
  file=open(filename,O_RDONLY | O_BINARY);
  if (file == -1)
    return((StringInfo *) NULL);
  offset=(MagickOffsetType) MagickSeek(file,0,SEEK_END);
  if ((offset < 0) || (offset != (MagickOffsetType) ((ssize_t) offset)))
    {
      file=close(file)-1;
      return((StringInfo *) NULL);
    }
  length=(size_t) offset;
  string=(char *) NULL;
  if (~length > MaxTextExtent)
    string=(char *) AcquireQuantumMemory(length+MaxTextExtent,sizeof(*string));
  if (string == (char *) NULL)
    {
      file=close(file)-1;
      return((StringInfo *) NULL);
    }
  map=MapBlob(file,ReadMode,0,length);
  if (map != (void *) NULL)
    {
      (void) CopyMagickMemory(string,map,length);
      (void) UnmapBlob(map,length);
    }
  else
    {
      register size_t
        i;

      ssize_t
        count;

      (void) MagickSeek(file,0,SEEK_SET);
      for (i=0; i < length; i+=count)
      {
        count=read(file,string+i,(size_t) MagickMin(length-i,(size_t)
          SSIZE_MAX));
        if (count <= 0)
          {
            count=0;
            if (errno != EINTR)
              break;
          }
      }
      if (i < length)
        {
          file=close(file)-1;
          string=DestroyString(string);
          return((StringInfo *) NULL);
        }
    }
  string[length]='\0';
  file=close(file)-1;
  string_info=AcquireStringInfo(0);
  (void) CopyMagickString(string_info->path,filename,MaxTextExtent);
  string_info->length=length;
  string_info->datum=(unsigned char *) string;
  return(string_info);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   C o n s t a n t S t r i n g                                               %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  ConstantString() allocates memory for a string and copies the source string
%  to that memory location (and returns it).  Use it for strings that you do
%  do not expect to change over its lifetime.
%
%  The format of the ConstantString method is:
%
%      char *ConstantString(const char *source)
%
%  A description of each parameter follows:
%
%    o source: A character string.
%
*/
MagickExport char *ConstantString(const char *source)
{
  char
    *destination;

  size_t
    length;

  length=0;
  if (source != (char *) NULL)
    length+=strlen(source);
  destination=(char *) NULL;
  if (~length >= 1UL)
    destination=(char *) AcquireQuantumMemory(length+1UL,sizeof(*destination));
  if (destination == (char *) NULL)
    ThrowFatalException(ResourceLimitFatalError,"UnableToAcquireString");
  *destination='\0';
  if (source != (char *) NULL)
    (void) CopyMagickString(destination,source,(length+1)*sizeof(*destination));
  return(destination);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   C o p y M a g i c k S t r i n g                                           %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  CopyMagickString() copies the source string to the destination string.  The
%  destination buffer is always null-terminated even if the string must be
%  truncated.
%
%  The format of the CopyMagickString method is:
%
%      size_t CopyMagickString(const char *destination,char *source,
%        const size_t length)
%
%  A description of each parameter follows:
%
%    o destination: the destination string.
%
%    o source: the source string.
%
%    o length: the length of the destination string.
%
*/
MagickExport size_t CopyMagickString(char *destination,const char *source,
  const size_t length)
{
  register char
    *q;

  register const char
    *p;

  register size_t
    n;

  p=source;
  q=destination;
  for (n=length; n > 4; n-=4)
  {
    *q=(*p++);
    if (*q == '\0')
      return((size_t) (p-source-1));
    q++;
    *q=(*p++);
    if (*q == '\0')
      return((size_t) (p-source-1));
    q++;
    *q=(*p++);
    if (*q == '\0')
      return((size_t) (p-source-1));
    q++;
    *q=(*p++);
    if (*q == '\0')
      return((size_t) (p-source-1));
    q++;
  }
  if (n != 0)
    for (n--; n != 0; n--)
    {
      *q=(*p++);
      if (*q == '\0')
        return((size_t) (p-source-1));
      q++;
    }
  if (length != 0)
    *q='\0';
  while (*p++ != '\0') ;
  return((size_t) (p-source-1));
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   D e s t r o y S t r i n g                                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  DestroyString() destroys memory associated with a string.
%
%  The format of the DestroyString method is:
%
%      char *DestroyString(char *string)
%
%  A description of each parameter follows:
%
%    o string: the string.
%
*/
MagickExport char *DestroyString(char *string)
{
  return((char *) RelinquishMagickMemory(string));
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   D e s t r o y S t r i n g I n f o                                         %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  DestroyStringInfo() destroys memory associated with the StringInfo structure.
%
%  The format of the DestroyStringInfo method is:
%
%      StringInfo *DestroyStringInfo(StringInfo *string_info)
%
%  A description of each parameter follows:
%
%    o string_info: the string info.
%
*/
MagickExport StringInfo *DestroyStringInfo(StringInfo *string_info)
{
  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
  assert(string_info != (StringInfo *) NULL);
  assert(string_info->signature == MagickSignature);
  if (string_info->datum != (unsigned char *) NULL)
    string_info->datum=(unsigned char *) RelinquishMagickMemory(
      string_info->datum);
  string_info->signature=(~MagickSignature);
  string_info=(StringInfo *) RelinquishMagickMemory(string_info);
  return(string_info);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   D e s t r o y S t r i n g L i s t                                         %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  DestroyStringList() zeros memory associated with a string list.
%
%  The format of the DestroyStringList method is:
%
%      char **DestroyStringList(char **list)
%
%  A description of each parameter follows:
%
%    o list: the string list.
%
*/
MagickExport char **DestroyStringList(char **list)
{
  register long
    i;

  assert(list != (char **) NULL);
  for (i=0; list[i] != (char *) NULL; i++)
    list[i]=DestroyString(list[i]);
  list=(char **) RelinquishMagickMemory(list);
  return(list);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   E s c a p e S t r i n g                                                   %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  EscapeString() allocates memory for a backslash-escaped version of a
%  source text string, copies the escaped version of the text to that
%  memory location while adding backslash characters, and returns the
%  escaped string.
%
%  The format of the EscapeString method is:
%
%      char *EscapeString(const char *source,const char escape)
%
%  A description of each parameter follows:
%
%    o allocate_string:  Method EscapeString returns the escaped string.
%
%    o source: A character string.
%
%    o escape: the quoted string termination character to escape (e.g. '"').
%
*/
MagickExport char *EscapeString(const char *source,const char escape)
{
  char
    *destination;

  register char
    *q;

  register const char
    *p;

  size_t
    length;

  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
  assert(source != (const char *) NULL);
  length=strlen(source);
  for (p=source; *p != '\0'; p++)
    if ((*p == '\\') || (*p == escape))
      {
        if (~length < 1)
          ThrowFatalException(ResourceLimitFatalError,"UnableToEscapeString");
        length++;
      }
  destination=(char *) NULL;
  if (~length >= MaxTextExtent)
    destination=(char *) AcquireQuantumMemory(length+MaxTextExtent,
      sizeof(*destination));
  if (destination == (char *) NULL)
    ThrowFatalException(ResourceLimitFatalError,"UnableToEscapeString");
  *destination='\0';
  if (source != (char *) NULL)
    {
      q=destination;
      for (p=source; *p != '\0'; p++)
      {
        if ((*p == '\\') || (*p == escape))
          *q++='\\';
        *q++=(*p);
      }
      *q='\0';
    }
  return(destination);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   F i l e T o S t r i n g                                                   %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  FileToString() returns the contents of a file as a string.
%
%  The format of the FileToString method is:
%
%      char *FileToString(const char *filename,const size_t extent,
%        ExceptionInfo *exception)
%
%  A description of each parameter follows:
%
%    o filename: the filename.
%
%    o extent: Maximum length of the string.
%
%    o exception: return any errors or warnings in this structure.
%
*/
MagickExport char *FileToString(const char *filename,const size_t extent,
  ExceptionInfo *exception)
{
  size_t
    length;

  assert(filename != (const char *) NULL);
  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",filename);
  assert(exception != (ExceptionInfo *) NULL);
  return((char *) FileToBlob(filename,extent,&length,exception));
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   F i l e T o S t r i n g I n f o                                           %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  FileToStringInfo() returns the contents of a file as a string.
%
%  The format of the FileToStringInfo method is:
%
%      StringInfo *FileToStringInfo(const char *filename,const size_t extent,
%        ExceptionInfo *exception)
%
%  A description of each parameter follows:
%
%    o filename: the filename.
%
%    o extent: Maximum length of the string.
%
%    o exception: return any errors or warnings in this structure.
%
*/
MagickExport StringInfo *FileToStringInfo(const char *filename,
  const size_t extent,ExceptionInfo *exception)
{
  StringInfo
    *string_info;

  assert(filename != (const char *) NULL);
  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",filename);
  assert(exception != (ExceptionInfo *) NULL);
  string_info=AcquireStringInfo(0);
  (void) CopyMagickString(string_info->path,filename,MaxTextExtent);
  string_info->datum=FileToBlob(filename,extent,&string_info->length,exception);
  if (string_info->datum == (unsigned char *) NULL)
    {
      string_info=DestroyStringInfo(string_info);
      return((StringInfo *) NULL);
    }
  return(string_info);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%  F o r m a t M a g i c k S i z e                                            %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  FormatMagickSize() converts a size to a human readable format, for example,
%  14kb, 234mb, 2.7gb, or 3.0tb.  Scaling is done by repetitively dividing by
%  1024.
%
%  The format of the FormatMagickSize method is:
%
%      long FormatMagickSize(const MagickSizeType size,char *format)
%
%  A description of each parameter follows:
%
%    o size:  convert this size to a human readable format.
%
%    o format:  human readable format.
%
*/
MagickExport long FormatMagickSize(const MagickSizeType size,char *format)
{
  double
    length;

  long
    count;

  register long
    i;

  static const char
    *units[] = { "b", "kb", "mb", "gb", "tb", "pb", "eb", (char *) NULL };

  length=(double) size;
  for (i=0; (length >= 1024.0) && (units[i+1] != (const char *) NULL); i++)
    length/=1024.0;
  count=FormatMagickString(format,MaxTextExtent,"%.*g%s",(int) (i+2),length,
    units[i]);
  return(count);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%  F o r m a t M a g i c k S t r i n g                                        %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  FormatMagickString() prints formatted output of a variable argument list.
%
%  The format of the FormatMagickString method is:
%
%      long FormatMagickString(char *string,const size_t length,
%        const char *format,...)
%
%  A description of each parameter follows.
%
%   o string:  FormatMagickString() returns the formatted string in this
%     character buffer.
%
%   o length: the maximum length of the string.
%
%   o format:  A string describing the format to use to write the remaining
%     arguments.
%
*/

MagickExport long FormatMagickStringList(char *string,const size_t length,
  const char *format,va_list operands)
{
  int
    n;

#if defined(MAGICKCORE_HAVE_VSNPRINTF)
  n=vsnprintf(string,length,format,operands);
#else
  n=vsprintf(string,format,operands);
#endif
  if (n < 0)
    string[length-1]='\0';
  return((long) n);
}

MagickExport long FormatMagickString(char *string,const size_t length,
  const char *format,...)
{
  long
    n;

  va_list
    operands;

  va_start(operands,format);
  n=(long) FormatMagickStringList(string,length,format,operands);
  va_end(operands);
  return(n);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%  F o r m a t M a g i c k T i m e                                            %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  FormatMagickTime() returns the specified time in the Internet date/time
%  format and the length of the timestamp.
%
%  The format of the FormatMagickTime method is:
%
%      long FormatMagickTime(const time_t time,const size_t length,
%        char *timestamp)
%
%  A description of each parameter follows.
%
%   o time:  the time since the Epoch (00:00:00 UTC, January 1, 1970),
%     measured in seconds.
%
%   o length: the maximum length of the string.
%
%   o timestamp:  Return the Internet date/time here.
%
*/
MagickExport long FormatMagickTime(const time_t time,const size_t length,
  char *timestamp)
{
  long
    count;

  struct tm
    local_time,
    utc_time;

  time_t
    timezone;

  assert(timestamp != (char *) NULL);
  local_time=(*localtime(&time));
  utc_time=(*gmtime(&time));
  timezone=(time_t) ((local_time.tm_min-utc_time.tm_min)/60+local_time.tm_hour-
    utc_time.tm_hour+24*((local_time.tm_year-utc_time.tm_year) != 0 ?
    (local_time.tm_year-utc_time.tm_year) : (local_time.tm_yday-
    utc_time.tm_yday)));
  count=FormatMagickString(timestamp,length,
    "%04d-%02d-%02dT%02d:%02d:%02d%+03ld:00",local_time.tm_year+1900,
    local_time.tm_mon+1,local_time.tm_mday,local_time.tm_hour,local_time.tm_min,
    local_time.tm_sec,(long) timezone);
  return(count);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   G e t E n v i r o n m e n t V a l u e                                     %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  GetEnvironmentValue() returns the environment string that matches the
%  specified name.
%
%  The format of the GetEnvironmentValue method is:
%
%      char *GetEnvironmentValue(const char *name)
%
%  A description of each parameter follows:
%
%    o name: the environment name.
%
*/
MagickExport char *GetEnvironmentValue(const char *name)
{
  const char
    *environment;

  environment=getenv(name);
  if (environment == (const char *) NULL)
    return((char *) NULL);
  return(ConstantString(environment));
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   G e t S t r i n g I n f o D a t u m                                       %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  GetStringInfoDatum() returns the datum associated with the string.
%
%  The format of the GetStringInfoDatum method is:
%
%      unsigned char *GetStringInfoDatum(const StringInfo *string_info)
%
%  A description of each parameter follows:
%
%    o string_info: the string info.
%
*/
MagickExport unsigned char *GetStringInfoDatum(const