X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fshared%2Futil.c;h=d5de59fce90955530cf0f2c121f46a41ca7caa41;hp=d771d321dd6a7d6a5cc7d4310409f849fb955f3d;hb=55c0b89c575fcb2c075286d444ed4fb1cf8c8563;hpb=7009eec20823add711e0aa452bdf9dfdd677fa4f diff --git a/src/shared/util.c b/src/shared/util.c index d771d321d..d5de59fce 100644 --- a/src/shared/util.c +++ b/src/shared/util.c @@ -108,105 +108,6 @@ bool streq_ptr(const char *a, const char *b) { return false; } -usec_t now(clockid_t clock_id) { - struct timespec ts; - - assert_se(clock_gettime(clock_id, &ts) == 0); - - return timespec_load(&ts); -} - -dual_timestamp* dual_timestamp_get(dual_timestamp *ts) { - assert(ts); - - ts->realtime = now(CLOCK_REALTIME); - ts->monotonic = now(CLOCK_MONOTONIC); - - return ts; -} - -dual_timestamp* dual_timestamp_from_realtime(dual_timestamp *ts, usec_t u) { - int64_t delta; - assert(ts); - - ts->realtime = u; - - if (u == 0) - ts->monotonic = 0; - else { - delta = (int64_t) now(CLOCK_REALTIME) - (int64_t) u; - - ts->monotonic = now(CLOCK_MONOTONIC); - - if ((int64_t) ts->monotonic > delta) - ts->monotonic -= delta; - else - ts->monotonic = 0; - } - - return ts; -} - -usec_t timespec_load(const struct timespec *ts) { - assert(ts); - - if (ts->tv_sec == (time_t) -1 && - ts->tv_nsec == (long) -1) - return (usec_t) -1; - - if ((usec_t) ts->tv_sec > (UINT64_MAX - (ts->tv_nsec / NSEC_PER_USEC)) / USEC_PER_SEC) - return (usec_t) -1; - - return - (usec_t) ts->tv_sec * USEC_PER_SEC + - (usec_t) ts->tv_nsec / NSEC_PER_USEC; -} - -struct timespec *timespec_store(struct timespec *ts, usec_t u) { - assert(ts); - - if (u == (usec_t) -1) { - ts->tv_sec = (time_t) -1; - ts->tv_nsec = (long) -1; - return ts; - } - - ts->tv_sec = (time_t) (u / USEC_PER_SEC); - ts->tv_nsec = (long int) ((u % USEC_PER_SEC) * NSEC_PER_USEC); - - return ts; -} - -usec_t timeval_load(const struct timeval *tv) { - assert(tv); - - if (tv->tv_sec == (time_t) -1 && - tv->tv_usec == (suseconds_t) -1) - return (usec_t) -1; - - if ((usec_t) tv->tv_sec > (UINT64_MAX - tv->tv_usec) / USEC_PER_SEC) - return (usec_t) -1; - - return - (usec_t) tv->tv_sec * USEC_PER_SEC + - (usec_t) tv->tv_usec; -} - -struct timeval *timeval_store(struct timeval *tv, usec_t u) { - assert(tv); - - if (u == (usec_t) -1) { - tv->tv_sec = (time_t) -1; - tv->tv_usec = (suseconds_t) -1; - return tv; - } - - tv->tv_sec = (time_t) (u / USEC_PER_SEC); - tv->tv_usec = (suseconds_t) (u % USEC_PER_SEC); - - return tv; -} - char* endswith(const char *s, const char *postfix) { size_t sl, pl; @@ -538,7 +439,6 @@ int get_parent_of_pid(pid_t pid, pid_t *_ppid) { if (!fgets(line, sizeof(line), f)) { r = feof(f) ? -EIO : -errno; - fclose(f); return r; } @@ -1004,13 +904,10 @@ int get_process_comm(pid_t pid, char **name) { } int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char **line) { - char *r, *k; + char *r = NULL, *k; int c; - bool space = false; - size_t left; FILE *f; - assert(max_length > 0); assert(line); if (pid == 0) @@ -1026,47 +923,64 @@ int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char * if (!f) return -errno; + if (max_length == 0) { + size_t len = 1; + while ((c = getc(f)) != EOF) { + k = realloc(r, len+1); + if (k == NULL) { + free(r); + fclose(f); + return -ENOMEM; + } + r = k; + r[len-1] = isprint(c) ? c : ' '; + r[len] = 0; + len++; + } + } else { + bool space = false; + size_t left; + r = new(char, max_length); + if (!r) { + fclose(f); + return -ENOMEM; + } - r = new(char, max_length); - if (!r) { - fclose(f); - return -ENOMEM; - } + k = r; + left = max_length; + while ((c = getc(f)) != EOF) { - k = r; - left = max_length; - while ((c = getc(f)) != EOF) { + if (isprint(c)) { + if (space) { + if (left <= 4) + break; + + *(k++) = ' '; + left--; + space = false; + } - if (isprint(c)) { - if (space) { if (left <= 4) break; - *(k++) = ' '; + *(k++) = (char) c; left--; - space = false; - } - - if (left <= 4) - break; + } else + space = true; + } - *(k++) = (char) c; - left--; - } else - space = true; + if (left <= 4) { + size_t n = MIN(left-1, 3U); + memcpy(k, "...", n); + k[n] = 0; + } else + *k = 0; } - if (left <= 4) { - size_t n = MIN(left-1, 3U); - memcpy(k, "...", n); - k[n] = 0; - } else - *k = 0; - fclose(f); /* Kernel threads have no argv[] */ - if (r[0] == 0) { + if (r == NULL || r[0] == 0) { char *t; int h; @@ -1956,136 +1870,6 @@ bool chars_intersect(const char *a, const char *b) { return false; } -char *format_timestamp(char *buf, size_t l, usec_t t) { - struct tm tm; - time_t sec; - - assert(buf); - assert(l > 0); - - if (t <= 0) - return NULL; - - sec = (time_t) (t / USEC_PER_SEC); - - if (strftime(buf, l, "%a, %Y-%m-%d %H:%M:%S %Z", localtime_r(&sec, &tm)) <= 0) - return NULL; - - return buf; -} - -char *format_timestamp_pretty(char *buf, size_t l, usec_t t) { - usec_t n, d; - - n = now(CLOCK_REALTIME); - - if (t <= 0 || t > n || t + USEC_PER_DAY*7 <= t) - return NULL; - - d = n - t; - - if (d >= USEC_PER_YEAR) - snprintf(buf, l, "%llu years and %llu months ago", - (unsigned long long) (d / USEC_PER_YEAR), - (unsigned long long) ((d % USEC_PER_YEAR) / USEC_PER_MONTH)); - else if (d >= USEC_PER_MONTH) - snprintf(buf, l, "%llu months and %llu days ago", - (unsigned long long) (d / USEC_PER_MONTH), - (unsigned long long) ((d % USEC_PER_MONTH) / USEC_PER_DAY)); - else if (d >= USEC_PER_WEEK) - snprintf(buf, l, "%llu weeks and %llu days ago", - (unsigned long long) (d / USEC_PER_WEEK), - (unsigned long long) ((d % USEC_PER_WEEK) / USEC_PER_DAY)); - else if (d >= 2*USEC_PER_DAY) - snprintf(buf, l, "%llu days ago", (unsigned long long) (d / USEC_PER_DAY)); - else if (d >= 25*USEC_PER_HOUR) - snprintf(buf, l, "1 day and %lluh ago", - (unsigned long long) ((d - USEC_PER_DAY) / USEC_PER_HOUR)); - else if (d >= 6*USEC_PER_HOUR) - snprintf(buf, l, "%lluh ago", - (unsigned long long) (d / USEC_PER_HOUR)); - else if (d >= USEC_PER_HOUR) - snprintf(buf, l, "%lluh %llumin ago", - (unsigned long long) (d / USEC_PER_HOUR), - (unsigned long long) ((d % USEC_PER_HOUR) / USEC_PER_MINUTE)); - else if (d >= 5*USEC_PER_MINUTE) - snprintf(buf, l, "%llumin ago", - (unsigned long long) (d / USEC_PER_MINUTE)); - else if (d >= USEC_PER_MINUTE) - snprintf(buf, l, "%llumin %llus ago", - (unsigned long long) (d / USEC_PER_MINUTE), - (unsigned long long) ((d % USEC_PER_MINUTE) / USEC_PER_SEC)); - else if (d >= USEC_PER_SEC) - snprintf(buf, l, "%llus ago", - (unsigned long long) (d / USEC_PER_SEC)); - else if (d >= USEC_PER_MSEC) - snprintf(buf, l, "%llums ago", - (unsigned long long) (d / USEC_PER_MSEC)); - else if (d > 0) - snprintf(buf, l, "%lluus ago", - (unsigned long long) d); - else - snprintf(buf, l, "now"); - - buf[l-1] = 0; - return buf; -} - -char *format_timespan(char *buf, size_t l, usec_t t) { - static const struct { - const char *suffix; - usec_t usec; - } table[] = { - { "w", USEC_PER_WEEK }, - { "d", USEC_PER_DAY }, - { "h", USEC_PER_HOUR }, - { "min", USEC_PER_MINUTE }, - { "s", USEC_PER_SEC }, - { "ms", USEC_PER_MSEC }, - { "us", 1 }, - }; - - unsigned i; - char *p = buf; - - assert(buf); - assert(l > 0); - - if (t == (usec_t) -1) - return NULL; - - if (t == 0) { - snprintf(p, l, "0"); - p[l-1] = 0; - return p; - } - - /* The result of this function can be parsed with parse_usec */ - - for (i = 0; i < ELEMENTSOF(table); i++) { - int k; - size_t n; - - if (t < table[i].usec) - continue; - - if (l <= 1) - break; - - k = snprintf(p, l, "%s%llu%s", p > buf ? " " : "", (unsigned long long) (t / table[i].usec), table[i].suffix); - n = MIN((size_t) k, l); - - l -= n; - p += n; - - t %= table[i].usec; - } - - *p = 0; - - return buf; -} - bool fstype_is_network(const char *fstype) { static const char table[] = "cifs\0" @@ -2754,164 +2538,6 @@ ssize_t loop_write(int fd, const void *buf, size_t nbytes, bool do_poll) { return n; } -int parse_usec(const char *t, usec_t *usec) { - static const struct { - const char *suffix; - usec_t usec; - } table[] = { - { "seconds", USEC_PER_SEC }, - { "second", USEC_PER_SEC }, - { "sec", USEC_PER_SEC }, - { "s", USEC_PER_SEC }, - { "minutes", USEC_PER_MINUTE }, - { "minute", USEC_PER_MINUTE }, - { "min", USEC_PER_MINUTE }, - { "months", USEC_PER_MONTH }, - { "month", USEC_PER_MONTH }, - { "msec", USEC_PER_MSEC }, - { "ms", USEC_PER_MSEC }, - { "m", USEC_PER_MINUTE }, - { "hours", USEC_PER_HOUR }, - { "hour", USEC_PER_HOUR }, - { "hr", USEC_PER_HOUR }, - { "h", USEC_PER_HOUR }, - { "days", USEC_PER_DAY }, - { "day", USEC_PER_DAY }, - { "d", USEC_PER_DAY }, - { "weeks", USEC_PER_WEEK }, - { "week", USEC_PER_WEEK }, - { "w", USEC_PER_WEEK }, - { "years", USEC_PER_YEAR }, - { "year", USEC_PER_YEAR }, - { "y", USEC_PER_YEAR }, - { "usec", 1ULL }, - { "us", 1ULL }, - { "", USEC_PER_SEC }, /* default is sec */ - }; - - const char *p; - usec_t r = 0; - - assert(t); - assert(usec); - - p = t; - do { - long long l; - char *e; - unsigned i; - - errno = 0; - l = strtoll(p, &e, 10); - - if (errno != 0) - return -errno; - - if (l < 0) - return -ERANGE; - - if (e == p) - return -EINVAL; - - e += strspn(e, WHITESPACE); - - for (i = 0; i < ELEMENTSOF(table); i++) - if (startswith(e, table[i].suffix)) { - r += (usec_t) l * table[i].usec; - p = e + strlen(table[i].suffix); - break; - } - - if (i >= ELEMENTSOF(table)) - return -EINVAL; - - } while (*p != 0); - - *usec = r; - - return 0; -} - -int parse_nsec(const char *t, nsec_t *nsec) { - static const struct { - const char *suffix; - nsec_t nsec; - } table[] = { - { "seconds", NSEC_PER_SEC }, - { "second", NSEC_PER_SEC }, - { "sec", NSEC_PER_SEC }, - { "s", NSEC_PER_SEC }, - { "minutes", NSEC_PER_MINUTE }, - { "minute", NSEC_PER_MINUTE }, - { "min", NSEC_PER_MINUTE }, - { "months", NSEC_PER_MONTH }, - { "month", NSEC_PER_MONTH }, - { "msec", NSEC_PER_MSEC }, - { "ms", NSEC_PER_MSEC }, - { "m", NSEC_PER_MINUTE }, - { "hours", NSEC_PER_HOUR }, - { "hour", NSEC_PER_HOUR }, - { "hr", NSEC_PER_HOUR }, - { "h", NSEC_PER_HOUR }, - { "days", NSEC_PER_DAY }, - { "day", NSEC_PER_DAY }, - { "d", NSEC_PER_DAY }, - { "weeks", NSEC_PER_WEEK }, - { "week", NSEC_PER_WEEK }, - { "w", NSEC_PER_WEEK }, - { "years", NSEC_PER_YEAR }, - { "year", NSEC_PER_YEAR }, - { "y", NSEC_PER_YEAR }, - { "usec", NSEC_PER_USEC }, - { "us", NSEC_PER_USEC }, - { "nsec", 1ULL }, - { "ns", 1ULL }, - { "", 1ULL }, /* default is nsec */ - }; - - const char *p; - nsec_t r = 0; - - assert(t); - assert(nsec); - - p = t; - do { - long long l; - char *e; - unsigned i; - - errno = 0; - l = strtoll(p, &e, 10); - - if (errno != 0) - return -errno; - - if (l < 0) - return -ERANGE; - - if (e == p) - return -EINVAL; - - e += strspn(e, WHITESPACE); - - for (i = 0; i < ELEMENTSOF(table); i++) - if (startswith(e, table[i].suffix)) { - r += (nsec_t) l * table[i].nsec; - p = e + strlen(table[i].suffix); - break; - } - - if (i >= ELEMENTSOF(table)) - return -EINVAL; - - } while (*p != 0); - - *nsec = r; - - return 0; -} - int parse_bytes(const char *t, off_t *bytes) { static const struct { const char *suffix; @@ -3238,6 +2864,9 @@ int get_ctty_devnr(pid_t pid, dev_t *d) { &ttynr) != 1) return -EIO; + if (major(ttynr) == 0 && minor(ttynr) == 0) + return -ENOENT; + *d = (dev_t) ttynr; return 0; } @@ -3256,7 +2885,8 @@ int get_ctty(pid_t pid, dev_t *_devnr, char **r) { snprintf(fn, sizeof(fn), "/dev/char/%u:%u", major(devnr), minor(devnr)); char_array_0(fn); - if ((k = readlink_malloc(fn, &s)) < 0) { + k = readlink_malloc(fn, &s); + if (k < 0) { if (k != -ENOENT) return k; @@ -3277,7 +2907,8 @@ int get_ctty(pid_t pid, dev_t *_devnr, char **r) { * symlink in /dev/char. Let's return something * vaguely useful. */ - if (!(b = strdup(fn + 5))) + b = strdup(fn + 5); + if (!b) return -ENOMEM; *r = b; @@ -4120,35 +3751,6 @@ int signal_from_string_try_harder(const char *s) { return signo; } -void dual_timestamp_serialize(FILE *f, const char *name, dual_timestamp *t) { - - assert(f); - assert(name); - assert(t); - - if (!dual_timestamp_is_set(t)) - return; - - fprintf(f, "%s=%llu %llu\n", - name, - (unsigned long long) t->realtime, - (unsigned long long) t->monotonic); -} - -void dual_timestamp_deserialize(const char *value, dual_timestamp *t) { - unsigned long long a, b; - - assert(value); - assert(t); - - if (sscanf(value, "%lli %llu", &a, &b) != 2) - log_debug("Failed to parse finish timestamp value %s", value); - else { - t->realtime = a; - t->monotonic = b; - } -} - static char *tag_to_udev_node(const char *tagvalue, const char *by) { char *dn, *t, *u; int r; @@ -4855,6 +4457,23 @@ int get_user_creds( return 0; } +char* uid_to_name(uid_t uid) { + struct passwd *p; + char *r; + + if (uid == 0) + return strdup("root"); + + p = getpwuid(uid); + if (p) + return strdup(p->pw_name); + + if (asprintf(&r, "%lu", (unsigned long) uid) < 0) + return NULL; + + return r; +} + int get_group_creds(const char **groupname, gid_t *gid) { struct group *g; gid_t id; @@ -5693,9 +5312,13 @@ int can_sleep(const char *type) { assert(type); + /* If /sys is read-only we cannot sleep */ + if (access("/sys/power/state", W_OK) < 0) + return false; + r = read_one_line_file("/sys/power/state", &p); if (r < 0) - return r == -ENOENT ? 0 : r; + return false; k = strlen(type); FOREACH_WORD_SEPARATOR(w, l, p, WHITESPACE, state) @@ -5713,9 +5336,14 @@ int can_sleep_disk(const char *type) { assert(type); + /* If /sys is read-only we cannot sleep */ + if (access("/sys/power/state", W_OK) < 0 || + access("/sys/power/disk", W_OK) < 0) + return false; + r = read_one_line_file("/sys/power/disk", &p); if (r < 0) - return r == -ENOENT ? 0 : r; + return false; k = strlen(type); FOREACH_WORD_SEPARATOR(w, l, p, WHITESPACE, state) { @@ -5968,139 +5596,6 @@ bool string_is_safe(const char *p) { return true; } -int parse_timestamp(const char *t, usec_t *usec) { - const char *k; - struct tm tm, copy; - time_t x; - usec_t plus = 0, minus = 0, ret; - int r; - - /* - * Allowed syntaxes: - * - * 2012-09-22 16:34:22 - * 2012-09-22 16:34 (seconds will be set to 0) - * 2012-09-22 (time will be set to 00:00:00) - * 16:34:22 (date will be set to today) - * 16:34 (date will be set to today, seconds to 0) - * now - * yesterday (time is set to 00:00:00) - * today (time is set to 00:00:00) - * tomorrow (time is set to 00:00:00) - * +5min - * -5days - * - */ - - assert(t); - assert(usec); - - x = time(NULL); - assert_se(localtime_r(&x, &tm)); - - if (streq(t, "now")) - goto finish; - - else if (streq(t, "today")) { - tm.tm_sec = tm.tm_min = tm.tm_hour = 0; - goto finish; - - } else if (streq(t, "yesterday")) { - tm.tm_mday --; - tm.tm_sec = tm.tm_min = tm.tm_hour = 0; - goto finish; - - } else if (streq(t, "tomorrow")) { - tm.tm_mday ++; - tm.tm_sec = tm.tm_min = tm.tm_hour = 0; - goto finish; - - } else if (t[0] == '+') { - - r = parse_usec(t+1, &plus); - if (r < 0) - return r; - - goto finish; - } else if (t[0] == '-') { - - r = parse_usec(t+1, &minus); - if (r < 0) - return r; - - goto finish; - } - - copy = tm; - k = strptime(t, "%y-%m-%d %H:%M:%S", &tm); - if (k && *k == 0) - goto finish; - - tm = copy; - k = strptime(t, "%Y-%m-%d %H:%M:%S", &tm); - if (k && *k == 0) - goto finish; - - tm = copy; - k = strptime(t, "%y-%m-%d %H:%M", &tm); - if (k && *k == 0) { - tm.tm_sec = 0; - goto finish; - } - - tm = copy; - k = strptime(t, "%Y-%m-%d %H:%M", &tm); - if (k && *k == 0) { - tm.tm_sec = 0; - goto finish; - } - - tm = copy; - k = strptime(t, "%y-%m-%d", &tm); - if (k && *k == 0) { - tm.tm_sec = tm.tm_min = tm.tm_hour = 0; - goto finish; - } - - tm = copy; - k = strptime(t, "%Y-%m-%d", &tm); - if (k && *k == 0) { - tm.tm_sec = tm.tm_min = tm.tm_hour = 0; - goto finish; - } - - tm = copy; - k = strptime(t, "%H:%M:%S", &tm); - if (k && *k == 0) - goto finish; - - tm = copy; - k = strptime(t, "%H:%M", &tm); - if (k && *k == 0) { - tm.tm_sec = 0; - goto finish; - } - - return -EINVAL; - -finish: - x = mktime(&tm); - if (x == (time_t) -1) - return -EINVAL; - - ret = (usec_t) x * USEC_PER_SEC; - - ret += plus; - if (ret > minus) - ret -= minus; - else - ret = 0; - - *usec = ret; - - return 0; -} - /* hey glibc, APIs with callbacks without a user pointer are so useless */ void *xbsearch_r(const void *key, const void *base, size_t nmemb, size_t size, int (*compar) (const void *, const void *, void *), void *arg) { @@ -6153,12 +5648,14 @@ const char *draw_special_char(DrawSpecialChar ch) { [DRAW_TREE_VERT] = "\342\224\202 ", /* │ */ [DRAW_TREE_BRANCH] = "\342\224\234\342\224\200", /* ├─ */ [DRAW_TREE_RIGHT] = "\342\224\224\342\224\200", /* └─ */ + [DRAW_TREE_SPACE] = " ", /* */ [DRAW_TRIANGULAR_BULLET] = "\342\200\243 ", /* ‣ */ }, /* ASCII fallback */ { [DRAW_TREE_VERT] = "| ", [DRAW_TREE_BRANCH] = "|-", [DRAW_TREE_RIGHT] = "`-", + [DRAW_TREE_SPACE] = " ", [DRAW_TRIANGULAR_BULLET] = "> ", } }; @@ -6215,3 +5712,164 @@ oom: free(r); return NULL; } + +char *strip_tab_ansi(char **ibuf, size_t *_isz) { + const char *i, *begin = NULL; + enum { + STATE_OTHER, + STATE_ESCAPE, + STATE_BRACKET + } state = STATE_OTHER; + char *obuf = NULL; + size_t osz = 0, isz; + FILE *f; + + assert(ibuf); + assert(*ibuf); + + /* Strips ANSI color and replaces TABs by 8 spaces */ + + isz = _isz ? *_isz : strlen(*ibuf); + + f = open_memstream(&obuf, &osz); + if (!f) + return NULL; + + for (i = *ibuf; i < *ibuf + isz + 1; i++) { + + switch (state) { + + case STATE_OTHER: + if (i >= *ibuf + isz) /* EOT */ + break; + else if (*i == '\x1B') + state = STATE_ESCAPE; + else if (*i == '\t') + fputs(" ", f); + else + fputc(*i, f); + break; + + case STATE_ESCAPE: + if (i >= *ibuf + isz) { /* EOT */ + fputc('\x1B', f); + break; + } else if (*i == '[') { + state = STATE_BRACKET; + begin = i + 1; + } else { + fputc('\x1B', f); + fputc(*i, f); + state = STATE_OTHER; + } + + break; + + case STATE_BRACKET: + + if (i >= *ibuf + isz || /* EOT */ + (!(*i >= '0' && *i <= '9') && *i != ';' && *i != 'm')) { + fputc('\x1B', f); + fputc('[', f); + state = STATE_OTHER; + i = begin-1; + } else if (*i == 'm') + state = STATE_OTHER; + break; + } + } + + if (ferror(f)) { + fclose(f); + free(obuf); + return NULL; + } + + fclose(f); + + free(*ibuf); + *ibuf = obuf; + + if (_isz) + *_isz = osz; + + return obuf; +} + +int on_ac_power(void) { + bool found_offline = false, found_online = false; + _cleanup_closedir_ DIR *d = NULL; + + d = opendir("/sys/class/power_supply"); + if (!d) + return -errno; + + for (;;) { + struct dirent *de; + union dirent_storage buf; + _cleanup_free_ char *p = NULL; + _cleanup_close_ int fd = -1, device = -1; + char contents[6]; + ssize_t n; + int k; + + k = readdir_r(d, &buf.de, &de); + if (k != 0) + return -k; + + if (!de) + break; + + if (ignore_file(de->d_name)) + continue; + + device = openat(dirfd(d), de->d_name, O_DIRECTORY|O_RDONLY|O_CLOEXEC|O_NOCTTY); + if (device < 0) { + if (errno == ENOENT || errno == ENOTDIR) + continue; + + return -errno; + } + + fd = openat(device, "type", O_RDONLY|O_CLOEXEC|O_NOCTTY); + if (fd < 0) { + if (errno == ENOENT) + continue; + + return -errno; + } + + n = read(fd, contents, sizeof(contents)); + if (n < 0) + return -errno; + + if (n != 6 || memcmp(contents, "Mains\n", 6)) + continue; + + close_nointr_nofail(fd); + fd = openat(device, "online", O_RDONLY|O_CLOEXEC|O_NOCTTY); + if (fd < 0) { + if (errno == ENOENT) + continue; + + return -errno; + } + + n = read(fd, contents, sizeof(contents)); + if (n < 0) + return -errno; + + if (n != 2 || contents[1] != '\n') + return -EIO; + + if (contents[0] == '1') { + found_online = true; + break; + } else if (contents[0] == '0') + found_offline = true; + else + return -EIO; + } + + return found_online || !found_offline; +}