fseek doesn't work properly
Conor P. Cahill
cpcahil at virtech.UUCP
Fri Oct 20 12:03:53 AEST 1989
In article <496 at his.UUCP>, jonas at his.UUCP (Jonas Mellin) writes:
> The problem:
> fseek moves the filepointer to beginning of the file
> regardless of the parameters
> Question:
> Does anyone else have this problem?
> fseek(fp,(long)i*sizeof(a),0);
> /* fseek(fp,(long)-sizeof(a),1); */
> fwrite(&a,sizeof(a),1,fp);
> fread(&a,sizeof(a),1,fp);
The problem probably is that you are using both the fread and fwrite
immediatly after each other.
My trusty manual specifies (on fopen(3s)):
When a file is opened for update, both input and output may be
done on the resulting stream. However, output may not be directly
followed by input without an intervening fseek, or rewind.....
RTM.
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