static proc_t *simple_readproc(PROCTAB *restrict const PT, proc_t *restrict const p) {
    static __thread struct utlbuf_s ub = { NULL, 0 };    // buf for stat,statm,status,cgroup
    static __thread struct stat sb;     // stat() buffer
    unsigned flags = PT->flags;
    int rc = 0;

    if (fstat(PT->pidfd, &sb) == -1)              /* no such dirent (anymore) */
        goto next_proc;

    if ((flags & PROC_UID) && !XinLN(uid_t, sb.st_uid, PT->uids, PT->nuid))
        goto next_proc;                      /* not one of the requested uids */

    p->euid = sb.st_uid;                        /* need a way to get real uid */
    p->egid = sb.st_gid;                        /* need a way to get real gid */

    /* this attempted read of 'stat' is now unconditional to ensure a 'cmd' name
       as a minimum. this prevents a NULL 'cmdline' pointer for kernel threads
       in case the 'status' file is missing or not otherwise read ... */
    if (file2str(PT->pidfd, "stat", &ub) == -1)
        goto next_proc;
    rc += stat2proc(ub.buf, p);
…
    if (flags & PROC_FILLMEM) {                 // read /proc/#/statm
        if (file2str(PT->pidfd, "statm", &ub) != -1)
            statm2proc(ub.buf, p);
    }

    if (flags & PROC_FILLSTATUS) {              // read /proc/#/status
        if (file2str(PT->pidfd, "status", &ub) != -1){
            rc += status2proc(ub.buf, p, 1);
…
        }
    }

    if (flags & PROC_FILLENV)                   // read /proc/#/environ
        if (!(p->environ_v = file2strvec(PT->pidfd, "environ")))
            rc += vectorize_dash_rc(&p->environ_v);
    if (flags & PROC_EDITENVRCVT)
        rc += fill_environ_cvt(PT->pidfd, p);

    if (flags & PROC_FILLARG)                   // read /proc/#/cmdline
        if (!(p->cmdline_v = file2strvec(PT->pidfd, "cmdline")))
            rc += vectorize_dash_rc(&p->cmdline_v);
    if (flags & PROC_EDITCMDLCVT)
        rc += fill_cmdline_cvt(PT->pidfd, p);
Warm-up
