C++ BamMultiReader::GetHeaderText方法代码示例

bool HeaderTool::HeaderToolPrivate::Run(void) {

    // set to default input if none provided
    if ( !m_settings->HasInput && !m_settings->HasInputFilelist )
        m_settings->InputFiles.push_back(Options::StandardIn());

    // add files in the filelist to the input file list
    if ( m_settings->HasInputFilelist ) {

        ifstream filelist(m_settings->InputFilelist.c_str(), ios::in);
        if ( !filelist.is_open() ) {
            cerr << "bamtools header ERROR: could not open input BAM file list... Aborting." << endl;
            return false;
        }

        string line;
        while ( getline(filelist, line) )
            m_settings->InputFiles.push_back(line);
    }

    // attemp to open BAM files
    BamMultiReader reader;
    if ( !reader.Open(m_settings->InputFiles) ) {
        cerr << "bamtools header ERROR: could not open BAM file(s) for reading... Aborting." << endl;
        return false;
    }

    // dump (merged) header contents to stdout
    cout << reader.GetHeaderText() << endl;

    // clean up & exit
    reader.Close();
    return true;
}

//.........这里部分代码省略.........
            cerr << "bamtools convert ERROR: could not locate index file(s)... Aborting." << endl;
            return false;
        }
    }

    // retrieve reference data
    m_references = reader.GetReferenceData();

    // set region if specified
    BamRegion region;
    if ( m_settings->HasRegion ) {
        if ( Utilities::ParseRegionString(m_settings->Region, reader, region) ) {

            if ( reader.HasIndexes() ) {
                if ( !reader.SetRegion(region) ) {
                    cerr << "bamtools convert ERROR: set region failed. Check that REGION describes a valid range" << endl;
                    reader.Close();
                    return false;
                }
            }

        } else {
            cerr << "bamtools convert ERROR: could not parse REGION: " << m_settings->Region << endl;
            cerr << "Check that REGION is in valid format (see documentation) and that the coordinates are valid"
                 << endl;
            reader.Close();
            return false;
        }
    }
        
    // if output file given
    ofstream outFile;
    if ( m_settings->HasOutput ) {
      
        // open output file stream
        outFile.open(m_settings->OutputFilename.c_str());
        if ( !outFile ) {
            cerr << "bamtools convert ERROR: could not open " << m_settings->OutputFilename
                 << " for output" << endl;
            return false; 
        }
        
        // set m_out to file's streambuf
        m_out.rdbuf(outFile.rdbuf()); 
    }
    
    // -------------------------------------
    // do conversion based on format
    
     bool convertedOk = true;
    
    // pileup is special case
    // conversion not done per alignment, like the other formats
    if ( m_settings->Format == FORMAT_PILEUP )
        convertedOk = RunPileupConversion(&reader);
    
    // all other formats
    else {
    
        bool formatError = false;
        
        // set function pointer to proper conversion method
        void (BamTools::ConvertTool::ConvertToolPrivate::*pFunction)(const BamAlignment&) = 0;
        if      ( m_settings->Format == FORMAT_BED )   pFunction = &BamTools::ConvertTool::ConvertToolPrivate::PrintBed;
        else if ( m_settings->Format == FORMAT_FASTA ) pFunction = &BamTools::ConvertTool::ConvertToolPrivate::PrintFasta;
        else if ( m_settings->Format == FORMAT_FASTQ ) pFunction = &BamTools::ConvertTool::ConvertToolPrivate::PrintFastq;
        else if ( m_settings->Format == FORMAT_JSON )  pFunction = &BamTools::ConvertTool::ConvertToolPrivate::PrintJson;
        else if ( m_settings->Format == FORMAT_SAM )   pFunction = &BamTools::ConvertTool::ConvertToolPrivate::PrintSam;
        else if ( m_settings->Format == FORMAT_YAML )  pFunction = &BamTools::ConvertTool::ConvertToolPrivate::PrintYaml;
        else { 
            cerr << "bamtools convert ERROR: unrecognized format: " << m_settings->Format << endl;
            cerr << "Please see documentation for list of supported formats " << endl;
            formatError = true;
            convertedOk = false;
        }
        
        // if format selected ok
        if ( !formatError ) {
        
            // if SAM format & not omitting header, print SAM header first
            if ( (m_settings->Format == FORMAT_SAM) && !m_settings->IsOmittingSamHeader ) 
                m_out << reader.GetHeaderText();
            
            // iterate through file, doing conversion
            BamAlignment a;
            while ( reader.GetNextAlignment(a) )
                (this->*pFunction)(a);
            
            // set flag for successful conversion
            convertedOk = true;
        }
    }
    
    // ------------------------
    // clean up & exit
    reader.Close();
    if ( m_settings->HasOutput )
        outFile.close();
    return convertedOk;   
}

bool RandomTool::RandomToolPrivate::Run(void) {

    // set to default stdin if no input files provided
    if ( !m_settings->HasInput && !m_settings->HasInputFilelist )
        m_settings->InputFiles.push_back(Options::StandardIn());

    // add files in the filelist to the input file list
    if ( m_settings->HasInputFilelist ) {

        ifstream filelist(m_settings->InputFilelist.c_str(), ios::in);
        if ( !filelist.is_open() ) {
            cerr << "bamtools random ERROR: could not open input BAM file list... Aborting." << endl;
            return false;
        }

        string line;
        while ( getline(filelist, line) )
            m_settings->InputFiles.push_back(line);
    }

    // open our reader
    BamMultiReader reader;
    if ( !reader.Open(m_settings->InputFiles) ) {
        cerr << "bamtools random ERROR: could not open input BAM file(s)... Aborting." << endl;
        return false;
    }

    // look up index files for all BAM files
    reader.LocateIndexes();

    // make sure index data is available
    if ( !reader.HasIndexes() ) {
        cerr << "bamtools random ERROR: could not load index data for all input BAM file(s)... Aborting." << endl;
        reader.Close();
        return false;
    }

    // get BamReader metadata
    const string headerText = reader.GetHeaderText();
    const RefVector references = reader.GetReferenceData();
    if ( references.empty() ) {
        cerr << "bamtools random ERROR: no reference data available... Aborting." << endl;
        reader.Close();
        return false;
    }

    // determine compression mode for BamWriter
    bool writeUncompressed = ( m_settings->OutputFilename == Options::StandardOut() &&
                              !m_settings->IsForceCompression );
    BamWriter::CompressionMode compressionMode = BamWriter::Compressed;
    if ( writeUncompressed ) compressionMode = BamWriter::Uncompressed;

    // open BamWriter
    BamWriter writer;
    writer.SetCompressionMode(compressionMode);
    if ( !writer.Open(m_settings->OutputFilename, headerText, references) ) {
        cerr << "bamtools random ERROR: could not open " << m_settings->OutputFilename
             << " for writing... Aborting." << endl;
        reader.Close();
        return false;
    }

    // if user specified a REGION constraint, attempt to parse REGION string
    BamRegion region;
    if ( m_settings->HasRegion && !Utilities::ParseRegionString(m_settings->Region, reader, region) ) {
        cerr << "bamtools random ERROR: could not parse REGION: " << m_settings->Region << endl;
        cerr << "Check that REGION is in valid format (see documentation) and that the coordinates are valid"
             << endl;
        reader.Close();
        writer.Close();
        return false;
    }

    // seed our random number generator
    srand( time(NULL) );

    // grab random alignments
    BamAlignment al;
    unsigned int i = 0;
    while ( i < m_settings->AlignmentCount ) {

        int randomRefId    = 0;
        int randomPosition = 0;

        // use REGION constraints to select random refId & position
        if ( m_settings->HasRegion ) {

            // select a random refId
            randomRefId = getRandomInt(region.LeftRefID, region.RightRefID);

            // select a random position based on randomRefId
            const int lowerBoundPosition = ( (randomRefId == region.LeftRefID)
                                             ? region.LeftPosition
                                             : 0 );
            const int upperBoundPosition = ( (randomRefId == region.RightRefID)
                                             ? region.RightPosition
                                             : (references.at(randomRefId).RefLength - 1) );
            randomPosition = getRandomInt(lowerBoundPosition, upperBoundPosition);
        }

//.........这里部分代码省略.........

int main ( int argc, char *argv[] ) { 

  struct parameters *param = 0;
  param = interface(param, argc, argv);


  //bam input and generate index if not yet 
  //-------------------------------------------------------------------------------------------------------+
  // BAM input (file or filenames?)                                                                        |
  //-------------------------------------------------------------------------------------------------------+
  char *fof = param->mapping_f;
  FILE *IN=NULL;
  char linefof[5000];
  int filecount=0;
  vector <string> fnames;

  if (strchr(fof,' ')!=NULL) {
    char *ptr;
    ptr=strtok(fof," ");
    while (ptr!=NULL) {
      fnames.push_back(ptr);
      filecount++;
      ptr=strtok(NULL," ");
    }
  } else {
    IN=fopen(fof,"rt");
    if (IN!=NULL) {
      long linecount=0;
      while (fgets(linefof,5000-1,IN)!=NULL) {
        linecount++;
        if (linefof[0]!='#' && linefof[0]!='\n') {
          char *ptr=strchr(linefof,'\n');
          if (ptr!=NULL && ptr[0]=='\n') {
            ptr[0]='\0';
          }
          FILE *dummy=NULL;
          dummy=fopen(linefof,"rt");
          if (dummy!=NULL) {     // seems to be a file of filenames...
            fclose(dummy);
            fnames.push_back(linefof);
            filecount++;
          } else if (filecount==0 || linecount>=1000-1) {  // seems to be a single file
            fnames.push_back(fof);
            filecount++;
            break;
          }
        }
      }
      fclose(IN);
    }
  }  //file or file name decided and stored in vector "fnames"

  cerr << "the input mapping files are:" << endl;
  vector <string>::iterator fit = fnames.begin();
  for(; fit != fnames.end(); fit++) {
    cerr << *fit << endl;
  }

  //-------------------------------------------------------------------------------------------------------+
  // end of file or filenames                                                                              |
  //-------------------------------------------------------------------------------------------------------+

  // open the BAM file(s)
  BamMultiReader reader;
  reader.Open(fnames);

  // get header & reference information
  string header = reader.GetHeaderText();
  RefVector refs = reader.GetReferenceData();


  // attempt to open BamWriter
  BamWriter writer;
  string outputBam = param->writer;
  if ( outputBam != "" ) {
    if ( !writer.Open(param->writer, header, refs) ) {
      cerr << "Could not open output BAM file" << endl;
      exit(0);
    }
  }


  BamAlignment bam;
  while (reader.GetNextAlignment(bam)) { //change RG 

    string rg = "RG";
    string rgType = "Z";
    string rgValue = "1";
    bam.EditTag(rg,rgType,rgValue);

    writer.SaveAlignment(bam);
    
  }  // read a bam

  return 0;

} //main

bool ConvertTool::ConvertToolPrivate::Run(void) {
 
    // ------------------------------------
    // initialize conversion input/output
        
    // set to default input if none provided
    if ( !m_settings->HasInput ) 
        m_settings->InputFiles.push_back(Options::StandardIn());
    
    // open input files
    BamMultiReader reader;
    if ( !m_settings->HasInput ) { // don't attempt to open index for stdin
        if ( !reader.Open(m_settings->InputFiles, false) ) {
            cerr << "Could not open input files" << endl;
            return false;
        }
    } else {
        if ( !reader.Open(m_settings->InputFiles, true) ) {
            if ( !reader.Open(m_settings->InputFiles, false) ) {
                cerr << "Could not open input files" << endl;
                return false;
            } else {
                cerr << "Opened reader without index file, jumping is disabled." << endl;
            }
        }
    }
    m_references = reader.GetReferenceData();

    // set region if specified
    BamRegion region;
    if ( m_settings->HasRegion ) {
        if ( Utilities::ParseRegionString(m_settings->Region, reader, region) ) {
            if ( !reader.SetRegion(region) ) {
                cerr << "Could not set BamReader region to REGION: " << m_settings->Region << endl;
                return false;
            }
        } else {
            cerr << "Could not parse REGION: " << m_settings->Region << endl;
            return false;
        }
    }
        
    // if output file given
    ofstream outFile;
    if ( m_settings->HasOutput ) {
      
        // open output file stream
        outFile.open(m_settings->OutputFilename.c_str());
        if ( !outFile ) {
            cerr << "Could not open " << m_settings->OutputFilename << " for output" << endl; 
            return false; 
        }
        
        // set m_out to file's streambuf
        m_out.rdbuf(outFile.rdbuf()); 
    }
    
    // -------------------------------------
    // do conversion based on format
    
     bool convertedOk = true;
    
    // pileup is special case
    // conversion not done per alignment, like the other formats
    if ( m_settings->Format == FORMAT_PILEUP )
        convertedOk = RunPileupConversion(&reader);
    
    // all other formats
    else {
    
        bool formatError = false;
        
        // set function pointer to proper conversion method
        void (BamTools::ConvertTool::ConvertToolPrivate::*pFunction)(const BamAlignment&) = 0;
        if      ( m_settings->Format == FORMAT_BED )      pFunction = &BamTools::ConvertTool::ConvertToolPrivate::PrintBed;
        else if ( m_settings->Format == FORMAT_BEDGRAPH ) pFunction = &BamTools::ConvertTool::ConvertToolPrivate::PrintBedGraph;
        else if ( m_settings->Format == FORMAT_FASTA )    pFunction = &BamTools::ConvertTool::ConvertToolPrivate::PrintFasta;
        else if ( m_settings->Format == FORMAT_FASTQ )    pFunction = &BamTools::ConvertTool::ConvertToolPrivate::PrintFastq;
        else if ( m_settings->Format == FORMAT_JSON )     pFunction = &BamTools::ConvertTool::ConvertToolPrivate::PrintJson;
        else if ( m_settings->Format == FORMAT_SAM )      pFunction = &BamTools::ConvertTool::ConvertToolPrivate::PrintSam;
        else if ( m_settings->Format == FORMAT_WIGGLE )   pFunction = &BamTools::ConvertTool::ConvertToolPrivate::PrintWiggle;
        else if ( m_settings->Format == FORMAT_YAML )     pFunction = &BamTools::ConvertTool::ConvertToolPrivate::PrintYaml;
        else { 
            cerr << "Unrecognized format: " << m_settings->Format << endl;
            cerr << "Please see help|README (?) for details on supported formats " << endl;
            formatError = true;
            convertedOk = false;
        }
        
        // if format selected ok
        if ( !formatError ) {
        
            // if SAM format & not omitting header, print SAM header first
            if ( (m_settings->Format == FORMAT_SAM) && !m_settings->IsOmittingSamHeader ) 
                m_out << reader.GetHeaderText();
            
            // iterate through file, doing conversion
            BamAlignment a;
            while ( reader.GetNextAlignment(a) )
              (this->*pFunction)(a);
//.........这里部分代码省略.........

bool FilterTool::FilterToolPrivate::Run(void) {
    
    // set to default input if none provided
    if ( !m_settings->HasInput && !m_settings->HasInputFilelist )
        m_settings->InputFiles.push_back(Options::StandardIn());

    // add files in the filelist to the input file list
    if ( m_settings->HasInputFilelist ) {

        ifstream filelist(m_settings->InputFilelist.c_str(), ios::in);
        if ( !filelist.is_open() ) {
            cerr << "bamtools filter ERROR: could not open input BAM file list... Aborting." << endl;
            return false;
        }

        string line;
        while ( getline(filelist, line) )
            m_settings->InputFiles.push_back(line);
    }

    // initialize defined properties & user-specified filters
    // quit if failed
    if ( !SetupFilters() )
        return false;

    // open reader without index
    BamMultiReader reader;
    if ( !reader.Open(m_settings->InputFiles) ) {
        cerr << "bamtools filter ERROR: could not open input files for reading." << endl;
        return false;
    }

    // retrieve reader header & reference data
    const string headerText = reader.GetHeaderText();
    filterToolReferences = reader.GetReferenceData();
    
    // determine compression mode for BamWriter
    bool writeUncompressed = ( m_settings->OutputFilename == Options::StandardOut() &&
                              !m_settings->IsForceCompression );
    BamWriter::CompressionMode compressionMode = BamWriter::Compressed;
    if ( writeUncompressed ) compressionMode = BamWriter::Uncompressed;

    // open BamWriter
    BamWriter writer;
    writer.SetCompressionMode(compressionMode);
    if ( !writer.Open(m_settings->OutputFilename, headerText, filterToolReferences) ) {
        cerr << "bamtools filter ERROR: could not open " << m_settings->OutputFilename << " for writing." << endl;
        reader.Close();
        return false;
    }

    // if no region specified, filter entire file 
    BamAlignment al;
    if ( !m_settings->HasRegion ) {
        while ( reader.GetNextAlignment(al) ) {
            if ( CheckAlignment(al) ) 
                writer.SaveAlignment(al);
        }
    }
    
    // otherwise attempt to use region as constraint
    else {
        
        // if region string parses OK
        BamRegion region;
        if ( Utilities::ParseRegionString(m_settings->Region, reader, region) ) {

            // attempt to find index files
            reader.LocateIndexes();

            // if index data available for all BAM files, we can use SetRegion
            if ( reader.HasIndexes() ) {

                // attempt to use SetRegion(), if failed report error
                if ( !reader.SetRegion(region.LeftRefID, region.LeftPosition, region.RightRefID, region.RightPosition) ) {
                    cerr << "bamtools filter ERROR: set region failed. Check that REGION describes a valid range" << endl;
                    reader.Close();
                    return false;
                } 
              
                // everything checks out, just iterate through specified region, filtering alignments
                while ( reader.GetNextAlignment(al) )
                    if ( CheckAlignment(al) ) 
                        writer.SaveAlignment(al);
                }
            
            // no index data available, we have to iterate through until we
            // find overlapping alignments
            else {
                while ( reader.GetNextAlignment(al) ) {
                    if ( (al.RefID >= region.LeftRefID)  && ((al.Position + al.Length) >= region.LeftPosition) &&
                         (al.RefID <= region.RightRefID) && ( al.Position <= region.RightPosition) ) 
                    {
                        if ( CheckAlignment(al) ) 
                            writer.SaveAlignment(al);
                    }
                }
            }
        } 
        
//.........这里部分代码省略.........

bool MergeTool::MergeToolPrivate::Run(void) {

    // set to default input if none provided
    if ( !m_settings->HasInputBamFilename )
        m_settings->InputFiles.push_back(Options::StandardIn());

    // opens the BAM files (by default without checking for indexes)
    BamMultiReader reader;
    if ( !reader.Open(m_settings->InputFiles) ) {
        cerr << "bamtools merge ERROR: could not open input BAM file(s)... Aborting." << endl;
        return false;
    }

    // retrieve header & reference dictionary info
    std::string mergedHeader = reader.GetHeaderText();
    RefVector references = reader.GetReferenceData();

    // determine compression mode for BamWriter
    bool writeUncompressed = ( m_settings->OutputFilename == Options::StandardOut() &&
                               !m_settings->IsForceCompression );
    BamWriter::CompressionMode compressionMode = BamWriter::Compressed;
    if ( writeUncompressed ) compressionMode = BamWriter::Uncompressed;

    // open BamWriter
    BamWriter writer;
    writer.SetCompressionMode(compressionMode);
    if ( !writer.Open(m_settings->OutputFilename, mergedHeader, references) ) {
        cerr << "bamtools merge ERROR: could not open "
             << m_settings->OutputFilename << " for writing." << endl;
        reader.Close();
        return false;
    }

    // if no region specified, store entire contents of file(s)
    if ( !m_settings->HasRegion ) {
        BamAlignment al;
        while ( reader.GetNextAlignmentCore(al) )
            writer.SaveAlignment(al);
    }

    // otherwise attempt to use region as constraint
    else {

        // if region string parses OK
        BamRegion region;
        if ( Utilities::ParseRegionString(m_settings->Region, reader, region) ) {

            // attempt to find index files
            reader.LocateIndexes();

            // if index data available for all BAM files, we can use SetRegion
            if ( reader.HasIndexes() ) {

                // attempt to use SetRegion(), if failed report error
                if ( !reader.SetRegion(region.LeftRefID,
                                       region.LeftPosition,
                                       region.RightRefID,
                                       region.RightPosition) )
                {
                    cerr << "bamtools merge ERROR: set region failed. Check that REGION describes a valid range"
                         << endl;
                    reader.Close();
                    return false;
                }

                // everything checks out, just iterate through specified region, storing alignments
                BamAlignment al;
                while ( reader.GetNextAlignmentCore(al) )
                    writer.SaveAlignment(al);
            }

            // no index data available, we have to iterate through until we
            // find overlapping alignments
            else {
                BamAlignment al;
                while ( reader.GetNextAlignmentCore(al) ) {
                    if ( (al.RefID >= region.LeftRefID)  && ( (al.Position + al.Length) >= region.LeftPosition ) &&
                         (al.RefID <= region.RightRefID) && ( al.Position <= region.RightPosition) )
                    {
                        writer.SaveAlignment(al);
                    }
                }
            }
        }

        // error parsing REGION string
        else {
            cerr << "bamtools merge ERROR: could not parse REGION - " << m_settings->Region << endl;
            cerr << "Check that REGION is in valid format (see documentation) and that the coordinates are valid"
                 << endl;
            reader.Close();
            writer.Close();
            return false;
        }
    }

    // clean & exit
    reader.Close();
    writer.Close();
    return true;
//.........这里部分代码省略.........

int main ( int argc, char *argv[] ) { 

  struct parameters *param = 0;
  param = interface(param, argc, argv);

  //region file input (the region file should be sorted as the same way as the bam file)
  ifstream region_f;
  region_f.open(param->region_f, ios_base::in);  // the region file is opened

  //bam input and generate index if not yet 
  //-------------------------------------------------------------------------------------------------------+
  // BAM input (file or filenames?)                                                                        |
  //-------------------------------------------------------------------------------------------------------+
  char *fof = param->mapping_f;
  FILE *IN=NULL;
  char linefof[5000];
  int filecount=0;
  vector <string> fnames;

  if (strchr(fof,' ')!=NULL) {
    char *ptr;
    ptr=strtok(fof," ");
    while (ptr!=NULL) {
      fnames.push_back(ptr);
      filecount++;
      ptr=strtok(NULL," ");
    }
  } else {
    IN=fopen(fof,"rt");
    if (IN!=NULL) {
      long linecount=0;
      while (fgets(linefof,5000-1,IN)!=NULL) {
        linecount++;
        if (linefof[0]!='#' && linefof[0]!='\n') {
          char *ptr=strchr(linefof,'\n');
          if (ptr!=NULL && ptr[0]=='\n') {
            ptr[0]='\0';
          }
          FILE *dummy=NULL;
          dummy=fopen(linefof,"rt");
          if (dummy!=NULL) {     // seems to be a file of filenames...
            fclose(dummy);
            fnames.push_back(linefof);
            filecount++;
          } else if (filecount==0 || linecount>=1000-1) {  // seems to be a single file
            fnames.push_back(fof);
            filecount++;
            break;
          }
        }
      }
      fclose(IN);
    }
  }  //file or file name decided and stored in vector "fnames"

  cerr << "the input mapping files are:" << endl;
  vector <string>::iterator fit = fnames.begin();
  for(; fit != fnames.end(); fit++) {
    cerr << *fit << endl;
  }

  //-------------------------------------------------------------------------------------------------------+
  // end of file or filenames                                                                              |
  //-------------------------------------------------------------------------------------------------------+

  // open the BAM file(s)
  BamMultiReader reader;
  reader.Open(fnames);

  // get header & reference information
  string header = reader.GetHeaderText();
  RefVector refs = reader.GetReferenceData();

  if ( ! reader.LocateIndexes() )     // opens any existing index files that match our BAM files
    reader.CreateIndexes();         // creates index files for BAM files that still lack one


  // locus bias
  struct lb empty_profile = {0,0,0,0};
  vector <struct lb> locus_b(1000, empty_profile);
  // output locus bias file
  string locus_bias_set = param->lbias;
  ofstream locus_bias;
  if ( locus_bias_set != "" ) {
    locus_bias.open(param->lbias);
    if ( !locus_bias ) {
      cerr << "can not open locus_bias file.\n";
      exit(0);
    }
  }

  //should decide which chromosome
  string line;
  string old_chr = "SRP";
  string type = param->type;

  //whether do some position-level pile-up stuff
  bool posc = false;
  ofstream posc_f;
  ofstream chrmap_f;
//.........这里部分代码省略.........

int MergeTool::Run(int argc, char* argv[]) {

    // parse command line arguments
    Options::Parse(argc, argv, 1);

    // set to default input if none provided
    if ( !m_settings->HasInputBamFilename )
        m_settings->InputFiles.push_back(Options::StandardIn());

    // opens the BAM files (by default without checking for indexes)
    BamMultiReader reader;
    if ( !reader.Open(m_settings->InputFiles, false, true) ) {
        cerr << "ERROR: Could not open input BAM file(s)... Aborting." << endl;
        return 1;
    }

    // retrieve header & reference dictionary info
    std::string mergedHeader = reader.GetHeaderText();
    RefVector references = reader.GetReferenceData();

    // open writer
    BamWriter writer;
    bool writeUncompressed = ( m_settings->OutputFilename == Options::StandardOut() && !m_settings->IsForceCompression );
    if ( !writer.Open(m_settings->OutputFilename, mergedHeader, references, writeUncompressed) ) {
        cerr << "ERROR: Could not open BAM file " << m_settings->OutputFilename << " for writing... Aborting." << endl;
        reader.Close();
        return 1;
    }

    // if no region specified, store entire contents of file(s)
    if ( !m_settings->HasRegion ) {
        BamAlignment al;
        while ( reader.GetNextAlignmentCore(al) )
            writer.SaveAlignment(al);
    }

    // otherwise attempt to use region as constraint
    else {

        // if region string parses OK
        BamRegion region;
        if ( Utilities::ParseRegionString(m_settings->Region, reader, region) ) {

            // attempt to re-open reader with index files
            reader.Close();
            bool openedOK = reader.Open(m_settings->InputFiles, true, true );

            // if error
            if ( !openedOK ) {
                cerr << "ERROR: Could not open input BAM file(s)... Aborting." << endl;
                return 1;
            }

            // if index data available, we can use SetRegion
            if ( reader.IsIndexLoaded() ) {

                // attempt to use SetRegion(), if failed report error
                if ( !reader.SetRegion(region.LeftRefID, region.LeftPosition, region.RightRefID, region.RightPosition) ) {
                    cerr << "ERROR: Region requested, but could not set BamReader region to REGION: " << m_settings->Region << " Aborting." << endl;
                    reader.Close();
                    return 1;
                }

                // everything checks out, just iterate through specified region, storing alignments
                BamAlignment al;
                while ( reader.GetNextAlignmentCore(al) )
                    writer.SaveAlignment(al);
            }

            // no index data available, we have to iterate through until we
            // find overlapping alignments
            else {
                BamAlignment al;
                while ( reader.GetNextAlignmentCore(al) ) {
                    if ( (al.RefID >= region.LeftRefID)  && ( (al.Position + al.Length) >= region.LeftPosition ) &&
                            (al.RefID <= region.RightRefID) && ( al.Position <= region.RightPosition) )
                    {
                        writer.SaveAlignment(al);
                    }
                }
            }
        }

        // error parsing REGION string
        else {
            cerr << "ERROR: Could not parse REGION - " << m_settings->Region << endl;
            cerr << "Be sure REGION is in valid format (see README) and that coordinates are valid for selected references" << endl;
            reader.Close();
            writer.Close();
            return 1;
        }
    }

    // clean & exit
    reader.Close();
    writer.Close();
    return 0;
}