Function read_pipe

src/engine/execnt.cpp:772–811

#define FORWARD_PIPE_STDERR 2

static void read_pipe
(
    HANDLE   in,  /* the pipe to read from */
    string * out,
    int32_t      forwarding_mode
)
{
    DWORD bytesInBuffer = 0;
    DWORD bytesAvailable = 0;
    DWORD i;

    for (;;)
    {
        /* check if we have any data to read */
        if ( !PeekNamedPipe( in, NULL, IO_BUFFER_SIZE, NULL,
            &bytesAvailable, NULL ) || bytesAvailable == 0 )
            return;

        /* we only read in the available bytes, to avoid blocking */
        if ( !ReadFile( in, ioBuffer, bytesAvailable <= IO_BUFFER_SIZE ?
            bytesAvailable : IO_BUFFER_SIZE, &bytesInBuffer, NULL ) || bytesInBuffer == 0 )
            return;

        /* Clean up some illegal chars. */
        for ( i = 0; i < bytesInBuffer; ++i )
        {
            if ( ( (unsigned char)ioBuffer[ i ] < 1 ) )
                ioBuffer[ i ] = '?';
        }
        /* Null, terminate. */
        ioBuffer[ bytesInBuffer ] = '\0';
        /* Append to the output. */
        string_append( out, ioBuffer );
        /* Copy it to our output if appropriate */
        if ( forwarding_mode == FORWARD_PIPE_STDOUT )
            out_data( ioBuffer );
        else if ( forwarding_mode == FORWARD_PIPE_STDERR )
            err_data( ioBuffer );
    }
}

#define EARLY_OUTPUT( cmd ) \
    ( ! ( cmd.flags & EXEC_CMD_QUIET ) )