#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>

int read_file( char *filename, int *len, char **data )
{
    int step = 1024*10;

    int file = open( filename, O_RDONLY );
    if ( file == -1 )
        return -1;

    int i = 0;
    while ( 1 )
    {
        *data = realloc( *data, step*(i+1));
        if ( data == NULL )
        {
            close( file );
            return -1;
        }

        int cur_len = read( file, *data+(step*i), step );
        if ( cur_len == 0 )
            break;
        else
            *len += cur_len;

        i++;
    }

    close( file );

    return 0;
}

int main( int argc, char *argv[] )
{
    int len = 0;
    char *pdata = NULL;
    char *pname = NULL;
    if ( argc == 2 )
        pname = argv[1];

    int nret = read_file( pname, &len, &pdata );
    if ( nret != 0 )
    {
        printf( "read file[%s] fail/n", pname );
    }

    printf( "file %s :len=%d;/n%s/n", pname, len, pdata );
    if ( pdata != NULL )
    {
        free( pdata);
        pdata = NULL;
    }

    return 0;
}