> Ahoi all...
> Im like lets starts something basic (basic might be a relative term),
> like a server that exports a ctl and a data file,
> every line written to ctl can be read from data with the letters sorted.
I did something like this some long time ago, I was told that using
9p(2)/9pfile(2) for such tiny things, which file structure does not change much
is not suggested - I actually did not get that.
Anyway, this may not even compile, I copied out of a source-tree. You want to
read it and understand every line, anyway, do you? ;)
#include <u.h>
#include <libc.h>
#include <fcall.h>
#include <thread.h>
#include <9p.h>
Srv *daefs;
/*
our file layout. Note that the enum Qstatus is
used in daefsfiles_create() to determine the size
of the array. Either fix the function or add files
(in any) before Qstatus.
*/
enum {
Qctl,
Qout,
Qstatus,
};
struct {
char name[20]; /* name of the file */
ulong mode; /* permission mode */
File *file; /* File-struct used by createfile() */
char *data; /* The data this file contains */
} daefsfiles[] = {
"ctl", 0666, nil, nil,
"output", 0444, nil, nil,
"status", 0444, nil, nil,
};
void daefs_write(Req *r) {
int i, myQid = (int)r->fid->file->qid.path;
if(myQid > Qstatus)
sysfatal("unknown Qid %d in write-call\n",myQid);
for(i=0;i+r->ifcall.offset < FILESIZE && i < r->ifcall.count;i++) {
daefsfiles[myQid].data[i+r->ifcall.offset] = r->ifcall.data[i];
r->ofcall.count++;
}
daefsfiles[myQid].file->length = r->ifcall.offset + r->ifcall.count;
if(myQid == Qctl) {
char *msg = daefsfiles[Qctl].data;
// Do your processing...
// Copy the string
strcpy(daefsfiles[Qstatus].data,msg);
// Do not forget to set the new length of the file, for stat(5)
etc.
daefsfiles[Qstatus].file->length = strlen(msg);
}
respond(r,nil);
}
void daefs_read(Req *r) {
readstr(r,daefsfiles[(int)r->fid->file->qid.path].data);
respond(r,nil);
}
void daefsfiles_create(void) {
int i;
if((daefs->tree = alloctree("daefs","daefs",DMDIR|0777,nil)) == nil)
sysfatal("daefs: daefsfiles_create(): alloctree() == nil");
for(i=0;i<=Qstatus;i++) {
daefsfiles[i].data = emalloc9p(FILESIZE);
if((daefsfiles[i].file = createfile(daefs->tree->root,
daefsfiles[i].name,"daefs", daefsfiles[i].mode,(void *)daefsfiles[i].data)) ==
nil)
sysfatal("daefs: daefsfiles_create() for file \"%s\":
createfile() == nil\n",daefsfiles[i].name);
}
daefs_status("ready\n");
}
void main(int argc, char **argv) {
char *mtpt = "/n/daefs/";
daefs = emalloc9p(sizeof(Srv));
daefs->write = daefs_write;
daefs->read = daefs_read;
daefsfiles_create();
threadpostmountsrv(daefs,"daefs",mtpt,0);
}
