ref: c1afd1158c54e93890168c7af3174ec1ac0914b8
dir: /sys/src/libc/9sys/putenv.c/
#include <u.h> #include <libc.h> int putenv(char *name, char *val) { char ename[100]; int f, n; if(name[0]=='\0' || strcmp(name, ".")==0 || strcmp(name, "..")==0 || strchr(name, '/')!=nil || strlen(name) >= sizeof(ename)-5){ werrstr("bad env name: %s", name); return -1; } snprint(ename, sizeof(ename), "/env/%s", name); f = create(ename, OWRITE|OCEXEC, 0664); if(f < 0) return -1; n = strlen(val); if(write(f, val, n) != n){ close(f); return -1; } close(f); return 0; }