there are 2 completely different processes A and B process A opens a file with fd 4 then i change the 'fs' and 'files' fields of the process descriptor of proc B to point to the respective fields of proc A ( i.e i let proc B share the 2 tables from proc A) then proc B opens a file with fd 5 then proc B does a dup2(5,4) sys call . //dup2(oldfd,newfd)
so would proc A be reading/writing the contents of fd=5(file opened by proc B) when it does a read/write on fd=4(file opened by proc A)? On Tue, Sep 29, 2009 at 3:48 PM, krushnaal pai <krisonea...@gmail.com>wrote: > even if process A does recv the file descriptions thru sockets how will it > use the file object of process B? > > > On Tue, Sep 29, 2009 at 2:58 PM, Luciano Rocha <luci...@eurotux.com>wrote: > >> On Tue, Sep 29, 2009 at 02:20:00PM +0530, krushnaal pai wrote: >> > i have 2 completely different processes A and B (they do not have any >> > relationship) >> > >> > suppose A opens a file with file descriptor 4 and >> > B opens another file with file descriptor 5 >> > >> > can process A use the fd 5 (i.e using the file object of processs B) by >> any >> > means.. >> >> You can pass file descriptions using unix sockets. Check "man 7 unix" >> for instructions. >> >> > if suppose i let the fd 4 of process A to point to the file object of >> > process B(fd 5) >> > >> > will it work? >> >> No. They will not share the file descriptor (offsets, flags, mode etc. >> will not be shared). >> >> >> -- >> Luciano Rocha <luci...@eurotux.com> >> Eurotux Informática, S.A. <http://www.eurotux.com/> >> > >
