>>>>> "d" == dblack <dblack@superlink.net> writes:
d> I always get 20 lines of output. But when I clone fh, I start to get
d> the behavior where one fh advances to EOF and the other doesn''t. I''m
d> afraid I''m still not seeing why cloning a file handle would or should
d> cause any of this to happen.
With your original example
d> fh = File.new("nums") # ''nums'' is 1..20, one integer per line
d> puts fh.gets
d>
d> fd = fh.clone
d> puts fd.gets
d>
d> puts fh.gets
it do this (well with some more tests :-)))
svg% cat nums
1
2
3
4
5
6
7
8
9
svg%
svg% cat a.c
#include <stdio.h>
main()
{
FILE *f1, *f2;
char line[1024];
f1 = fopen("nums", "r");
line[0] = line[1] = line[2] = 0;
fread(line, 1, 2, f1);
printf("%s", line);
fseeko(f1, 0L, SEEK_CUR);
f2 = fdopen(dup(fileno(f1)), "r");
line[0] = line[1] = 0;
fread(line, 1, 2, f2);
printf("%s", line);
line[0] = line[1] = 0;
if (fread(line, 1, 2, f1) == 0) {
printf("EOF\n");
}
else {
printf("%s", line);
}
}
svg%
svg% a.out
1
2
EOF
svg%
Guy Decoux