ref: 1211f12e03cb1af1ea3ec5f3ae0159d393a3d9e8
dir: /sys/src/libc/9sys/putenv.c/
#include <u.h>
#include <libc.h>
int
putenv(char *name, char *val)
{
int f;
char ename[100];
long s;
if(strchr(name, '/') != nil)
return -1;
snprint(ename, sizeof ename, "/env/%s", name);
if(strcmp(ename+5, name) != 0)
return -1;
f = create(ename, OWRITE, 0664);
if(f < 0)
return -1;
s = strlen(val);
if(write(f, val, s) != s){
close(f);
return -1;
}
close(f);
return 0;
}