iterfrec.cpp

来自「开放源码的编译器open watcom 1.6.0版的源代码」· C++ 代码 · 共 95 行

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// ITERFREC -- implementation of file-record iterations
//
// 92/12/30 -- J.W.Welch        -- defined

#include "iterfrec.h"
#include "excfile.h"

//---------------------------------------------------------------------------
// IterFileRec -- iterator for file of records
//---------------------------------------------------------------------------

IterFileRec::IterFileRec(       // Constructor
    const char* fname,          // - file name
    ifstream &file,             // - file structure
    Boolean &retn,              // - TRUE ==> opened
    Boolean reqd )              // - TRUE ==> file must exist
    : filename( fname )
    , file( file )
{
    file.open( fname, ( ios::in | ios::nocreate ) );
    if( ! file ) {
        if( reqd ) {
            throw ExcFileOpenInput( fname );
        } else {
            retn = FALSE;
        }
    } else {
        retn = TRUE;
    }
}


IterFileRec::~IterFileRec(      // Destructor
    void )
{
    file.close();
}


Boolean IterFileRec::next(      // GET NEXT RECORD
    void )
{
    Boolean retn;               // - TRUE ==> have data

    file.getline( buffer, sizeof( buffer ) - 1 );
    if( file.eof() ) {
        retn = FALSE;
    } else if( file.fail() ) {
        throw ExcFileRead( filename );
    } else {
        buffer[ strlen( buffer ) - 1 ] = '\0';
        retn = TRUE;
    }
    return retn;
}


void *IterFileRec::element(     // POINT AT ELEMENT
    void ) const
{
    return buffer;
}