From: j DOT aldrich6 AT genie DOT com
Message-Id: <199605091349.AA117369770@relay1.geis.com>
Date: Thu,  9 May 96 13:41:00 UTC 0000
To: djgpp AT delorie DOT com
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Subject: Re: i/o file handling - intege

Reply to message 1888818    from THUNBERG AT ALGO on 05/06/96  5:40PM


>What is the appropriate way to read/write integers from/to a file with the
same
>size as it is stored in
>memory, i.e. a long integer (32bit) would occupy 4 bytes in the file. I have
>reached a solution but it seems
>rather clumsy:

Whoever taught you C obviously forgot to mention the fread() and fwrite()
functions for reading and writing binary data to files.

#define X 10

FILE *fp;
int n[X], m[X], i;

for ( i = 0; i < X; i++ )
    scanf( "%d", n[i] );

fp = fopen( "foo.dat", "w+b" );
fwrite( n, sizeof(*n), X, fp );

fflush( fp );
rewind( fp );

if ( fread( &m, sizeof(*m), X, fp ) != X)    /* returns # of items read */
    printf( "Oops.\n" );
else
    for ( i = 0; i < X; i++ )
        printf( "%d  ", m[i] );

fclose( fp );