On 07/03/2013 01:37 PM, captaindet wrote:
> in C:
>
> typedef struct { /* info */ } INFO;
> INFO info;
> size_t checkio;
> // read INFO from data file:
> pf_datafile = fopen("datafile","rb");
> checkio = fread((char *) &info, sizeof(info), 1, pf_datafile);
Just a reminder: The operation above is not portable. There are
endianness and struct member padding issues.
> how do i do this in D?
Assuming that the writer and the reader agree that it works, the closest
in Phobos is std.stdio.rawRead.
> the INFO struct might be anywhere in the file, not only at the beginning.
seek() does that.
import std.stdio;
struct Info
{
size_t a;
double b;
byte c;
}
void main()
{
auto info0 = Info(1, 2.25, 3);
auto info1 = Info(4, 5.50, 6);
writeTest("test_file", [ info0, info1 ]);
readTest("test_file", 0);
readTest("test_file", 1);
}
void writeTest(string fileName, const(Info)[] infos)
{
auto file = File(fileName, "w");
file.rawWrite(infos);
}
void readTest(string fileName, size_t index)
{
auto file = File(fileName, "r");
auto offset = index * Info.sizeof;
file.seek(offset);
// More than 1 would read as many elements
auto info = new Info[1];
file.rawRead(info);
writefln("Read Info at index %s: %s", index, info);
}
Ali
