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#include <u.h>
#include <libc.h>
#include <ctype.h>
static int
isme(char *uid)
{
int n;
char *p;
n = strtol(uid, &p, 10);
if(*p == 0 && p > uid)
return n == getuid();
return strcmp(getuser(), uid) == 0;
}
/*
* Absent other hints, it works reasonably well to use
* the X11 display name as the name space identifier.
* This is how sam's B has worked since the early days.
* Since most programs using name spaces are also using X,
* this still seems reasonable. Terminal-only sessions
* can set $NAMESPACE.
*/
static char*
nsfromdisplay(void)
{
int fd;
Dir *d;
char *disp, *p;
if((disp = getenv("DISPLAY")) == nil){
werrstr("$DISPLAY not set");
return nil;
}
/* canonicalize: xxx:0.0 => xxx:0 */
p = strrchr(disp, ':');
if(p){
p++;
while(isdigit((uchar)*p))
p++;
if(strcmp(p, ".0") == 0)
*p = 0;
}
p = smprint("/tmp/ns.%s.%s", getuser(), disp);
free(disp);
if(p == nil){
werrstr("out of memory");
return p;
}
if((fd=create(p, OREAD, DMDIR|0700)) >= 0){
close(fd);
return p;
}
if((d = dirstat(p)) == nil){
free(d);
werrstr("stat %s: %r", p);
free(p);
return nil;
}
if((d->mode&0777) != 0700 || !isme(d->uid)){
werrstr("bad name space dir %s", p);
free(p);
free(d);
return nil;
}
free(d);
return p;
}
char*
getns(void)
{
char *ns;
ns = getenv("NAMESPACE");
if(ns == nil)
ns = nsfromdisplay();
if(ns == nil){
werrstr("$NAMESPACE not set, %r");
return nil;
}
return ns;
}
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