ref: a4ab5e6fa6ac1ad7937a46213288b476879cebd4
dir: /sys/src/ape/lib/ap/gen/getenv.c/
#include <stdlib.h>
extern char **environ;
char *
getenv(const char *name)
{
char **p = environ;
char *v, *s1, *s2;
while (*p != NULL){
for(s1 = (char *)name, s2 = *p++; *s1 == *s2; s1++, s2++)
continue;
if(*s1 == '\0' && *s2 == '=')
return s2+1;
}
return NULL ;
}