source: trunk/minix/commands/i386/mtools-3.9.7/copyfile.c@ 10

#include "sysincludes.h"
#include "msdos.h"
#include "mtools.h"
#include "file.h"
#include "llong.h"

/*
 * Copy the data from source to target
 */

int copyfile(Stream_t *Source, Stream_t *Target)
{
        char buffer[8*16384];
        int pos;
        int ret, retw;
        size_t len;
        mt_size_t mt_len;

        if (!Source){
                fprintf(stderr,"Couldn't open source file\n");
                return -1;
        }

        if (!Target){
                fprintf(stderr,"Couldn't open target file\n");
                return -1;
        }

        pos = 0;
        GET_DATA(Source, 0, &mt_len, 0, 0);
        if (mt_len & ~max_off_t_31) {
                fprintf(stderr, "File too big\n");
                return -1;
        }
        len = truncBytes32(mt_len);
        while(1){
                ret = READS(Source, buffer, (mt_off_t) pos, 8*16384);
                if (ret < 0 ){
                        perror("file read");
                        return -1;
                }
                if(!ret)
                        break;
                if(got_signal)
                        return -1;
                if (ret == 0)
                        break;
                if ((retw = force_write(Target, buffer, (mt_off_t) pos, ret)) != ret){
                        if(retw < 0 )
                                perror("write in copy");
                        else
                                fprintf(stderr,
                                        "Short write %d instead of %d\n", retw,
                                        ret);
                        if(errno == ENOSPC)
                                got_signal = 1;
                        return ret;
                }
                pos += ret;
        }
        return pos;
}