tree-wide: add global ascii_isdigit() + ascii_isalpha()

We now have a local implementation in string-util-fundamental.c, but
it's useful at a lot of other places, hence let's give it a more
expressive name and share it across the tree.

Follow-up for: 8d9156660d6958c8d63b1d44692968f1b5d33920

25 files changed, 68 insertions, 89 deletions

diff --git a/src/basic/bus-label.c b/src/basic/bus-label.c
index cd6c58a3d3..d33fc92290 100644
--- a/src/basic/bus-label.c
+++ b/src/basic/bus-label.c
@@ -26,12 +26,10 @@ char *bus_label_escape(const char *s) {
 
         for (f = s, t = r; *f; f++) {
 
-                /* Escape everything that is not a-zA-Z0-9. We also
-                 * escape 0-9 if it's the first character */
+                /* Escape everything that is not a-zA-Z0-9. We also escape 0-9 if it's the first character */
 
-                if (!(*f >= 'A' && *f <= 'Z') &&
-                    !(*f >= 'a' && *f <= 'z') &&
-                    !(f > s && *f >= '0' && *f <= '9')) {
+                if (!ascii_isalpha(*f) &&
+                    !(f > s && ascii_isdigit(*f))) {
                         *(t++) = '_';
                         *(t++) = hexchar(*f >> 4);
                         *(t++) = hexchar(*f);
diff --git a/src/basic/env-util.c b/src/basic/env-util.c
index b60c9f9fdc..62914f1587 100644
--- a/src/basic/env-util.c
+++ b/src/basic/env-util.c
@@ -32,7 +32,7 @@ static bool env_name_is_valid_n(const char *e, size_t n) {
         if (n <= 0)
                 return false;
 
-        if (e[0] >= '0' && e[0] <= '9')
+        if (ascii_isdigit(e[0]))
                 return false;
 
         /* POSIX says the overall size of the environment block cannot
diff --git a/src/basic/hostname-util.c b/src/basic/hostname-util.c
index d5d1388102..b710f07929 100644
--- a/src/basic/hostname-util.c
+++ b/src/basic/hostname-util.c
@@ -75,10 +75,8 @@ int gethostname_full(GetHostnameFlags flags, char **ret) {
 bool valid_ldh_char(char c) {
         /* "LDH" → "Letters, digits, hyphens", as per RFC 5890, Section 2.3.1 */
 
-        return
-                (c >= 'a' && c <= 'z') ||
-                (c >= 'A' && c <= 'Z') ||
-                (c >= '0' && c <= '9') ||
+        return ascii_isalpha(c) ||
+                ascii_isdigit(c) ||
                 c == '-';
 }
 
diff --git a/src/basic/parse-util.c b/src/basic/parse-util.c
index 35fbb5ec6a..787a681870 100644
--- a/src/basic/parse-util.c
+++ b/src/basic/parse-util.c
@@ -210,7 +210,7 @@ int parse_size(const char *t, uint64_t base, uint64_t *size) {
                         e++;
 
                         /* strtoull() itself would accept space/+/- */
-                        if (*e >= '0' && *e <= '9') {
+                        if (ascii_isdigit(*e)) {
                                 unsigned long long l2;
                                 char *e2;
 
@@ -599,7 +599,7 @@ int parse_fractional_part_u(const char **p, size_t digits, unsigned *res) {
 
         /* accept any number of digits, strtoull is limited to 19 */
         for (size_t i = 0; i < digits; i++,s++) {
-                if (*s < '0' || *s > '9') {
+                if (!ascii_isdigit(*s)) {
                         if (i == 0)
                                 return -EINVAL;
 
diff --git a/src/basic/socket-util.c b/src/basic/socket-util.c
index c642718e95..f39be19a59 100644
--- a/src/basic/socket-util.c
+++ b/src/basic/socket-util.c
@@ -833,7 +833,7 @@ bool ifname_valid_full(const char *p, IfnameValidFlags flags) {
                 if (!ifname_valid_char(*t))
                         return false;
 
-                numeric = numeric && (*t >= '0' && *t <= '9');
+                numeric = numeric && ascii_isdigit(*t);
         }
 
         /* It's fully numeric but didn't parse as valid ifindex above? if so, it must be too large or zero or
diff --git a/src/basic/terminal-util.c b/src/basic/terminal-util.c
index a142ba2dfb..0c092597eb 100644
--- a/src/basic/terminal-util.c
+++ b/src/basic/terminal-util.c
@@ -624,7 +624,7 @@ int vtnr_from_tty(const char *tty) {
         if (!startswith(tty, "tty") )
                 return -EINVAL;
 
-        if (tty[3] < '0' || tty[3] > '9')
+        if (!ascii_isdigit(tty[3]))
                 return -EINVAL;
 
         r = safe_atoi(tty+3, &i);
diff --git a/src/basic/time-util.c b/src/basic/time-util.c
index c309369406..abbc4ad5cd 100644
--- a/src/basic/time-util.c
+++ b/src/basic/time-util.c
@@ -1411,9 +1411,8 @@ int verify_timezone(const char *name, int log_level) {
                 return -EINVAL;
 
         for (p = name; *p; p++) {
-                if (!(*p >= '0' && *p <= '9') &&
-                    !(*p >= 'a' && *p <= 'z') &&
-                    !(*p >= 'A' && *p <= 'Z') &&
+                if (!ascii_isdigit(*p) &&
+                    !ascii_isalpha(*p) &&
                     !IN_SET(*p, '-', '_', '+', '/'))
                         return -EINVAL;
 
diff --git a/src/basic/user-util.c b/src/basic/user-util.c
index 8b1283a9ec..16185332f9 100644
--- a/src/basic/user-util.c
+++ b/src/basic/user-util.c
@@ -814,15 +814,13 @@ bool valid_user_group_name(const char *u, ValidUserFlags flags) {
                  * Note that other systems are even more restrictive, and don't permit underscores or uppercase characters.
                  */
 
-                if (!(u[0] >= 'a' && u[0] <= 'z') &&
-                    !(u[0] >= 'A' && u[0] <= 'Z') &&
+                if (!ascii_isalpha(u[0]) &&
                     u[0] != '_')
                         return false;
 
                 for (i = u+1; *i; i++)
-                        if (!(*i >= 'a' && *i <= 'z') &&
-                            !(*i >= 'A' && *i <= 'Z') &&
-                            !(*i >= '0' && *i <= '9') &&
+                        if (!ascii_isalpha(*i) &&
+                            !ascii_isdigit(*i) &&
                             !IN_SET(*i, '_', '-'))
                                 return false;
 
diff --git a/src/fundamental/string-util-fundamental.c b/src/fundamental/string-util-fundamental.c
index 6f690b9c90..11701ebe52 100644
--- a/src/fundamental/string-util-fundamental.c
+++ b/src/fundamental/string-util-fundamental.c
@@ -77,18 +77,8 @@ sd_char* endswith_no_case(const sd_char *s, const sd_char *postfix) {
         return (sd_char*) s + sl - pl;
 }
 
-static bool is_digit(sd_char a) {
-        /* Locale-independent version of isdigit(). */
-        return a >= '0' && a <= '9';
-}
-
-static bool is_alpha(sd_char a) {
-        /* Locale-independent version of isalpha(). */
-        return (a >= 'a' && a <= 'z') || (a >= 'A' && a <= 'Z');
-}
-
 static bool is_valid_version_char(sd_char a) {
-        return is_digit(a) || is_alpha(a) || IN_SET(a, '~', '-', '^', '.');
+        return ascii_isdigit(a) || ascii_isalpha(a) || IN_SET(a, '~', '-', '^', '.');
 }
 
 int strverscmp_improved(const sd_char *a, const sd_char *b) {
@@ -186,12 +176,12 @@ int strverscmp_improved(const sd_char *a, const sd_char *b) {
                         b++;
                 }
 
-                if (is_digit(*a) || is_digit(*b)) {
+                if (ascii_isdigit(*a) || ascii_isdigit(*b)) {
                         /* Find the leading numeric segments. One may be an empty string. So,
                          * numeric segments are always newer than alpha segments. */
-                        for (aa = a; is_digit(*aa); aa++)
+                        for (aa = a; ascii_isdigit(*aa); aa++)
                                 ;
-                        for (bb = b; is_digit(*bb); bb++)
+                        for (bb = b; ascii_isdigit(*bb); bb++)
                                 ;
 
                         /* Check if one of the strings was empty, but the other not. */
@@ -217,9 +207,9 @@ int strverscmp_improved(const sd_char *a, const sd_char *b) {
                                 return r;
                 } else {
                         /* Find the leading non-numeric segments. */
-                        for (aa = a; is_alpha(*aa); aa++)
+                        for (aa = a; ascii_isalpha(*aa); aa++)
                                 ;
-                        for (bb = b; is_alpha(*bb); bb++)
+                        for (bb = b; ascii_isalpha(*bb); bb++)
                                 ;
 
                         /* Note that the segments are usually not NUL-terminated. */
diff --git a/src/fundamental/string-util-fundamental.h b/src/fundamental/string-util-fundamental.h
index 72fa0d7c90..ecf32e519f 100644
--- a/src/fundamental/string-util-fundamental.h
+++ b/src/fundamental/string-util-fundamental.h
@@ -104,3 +104,13 @@ static inline void *memory_startswith(const void *p, size_t sz, const sd_char *t
 
 #define STRV_FOREACH(s, l)                      \
         _STRV_FOREACH(s, l, UNIQ_T(i, UNIQ))
+
+static inline bool ascii_isdigit(sd_char a) {
+        /* A pure ASCII, locale independent version of isdigit() */
+        return a >= '0' && a <= '9';
+}
+
+static inline bool ascii_isalpha(sd_char a) {
+        /* A pure ASCII, locale independent version of isalpha() */
+        return (a >= 'a' && a <= 'z') || (a >= 'A' && a <= 'Z');
+}
diff --git a/src/journal/journald-audit.c b/src/journal/journald-audit.c
index ea535a27af..3e87a93a9e 100644
--- a/src/journal/journald-audit.c
+++ b/src/journal/journald-audit.c
@@ -161,9 +161,8 @@ static int map_generic_field(
                 if (*e == '=')
                         break;
 
-                if (!((*e >= 'a' && *e <= 'z') ||
-                      (*e >= 'A' && *e <= 'Z') ||
-                      (*e >= '0' && *e <= '9') ||
+                if (!(ascii_isalpha(*e) ||
+                      ascii_isdigit(*e) ||
                       IN_SET(*e, '_', '-')))
                         return 0;
         }
diff --git a/src/journal/journald-syslog.c b/src/journal/journald-syslog.c
index 925bd502d3..ce02378675 100644
--- a/src/journal/journald-syslog.c
+++ b/src/journal/journald-syslog.c
@@ -279,14 +279,13 @@ static int syslog_skip_timestamp(const char **buf) {
 
                         _fallthrough_;
                 case NUMBER:
-                        if (*p < '0' || *p > '9')
+                        if (!ascii_isdigit(*p))
                                 return 0;
 
                         break;
 
                 case LETTER:
-                        if (!(*p >= 'A' && *p <= 'Z') &&
-                            !(*p >= 'a' && *p <= 'z'))
+                        if (!ascii_isalpha(*p))
                                 return 0;
 
                         break;
diff --git a/src/libsystemd/sd-bus/bus-internal.c b/src/libsystemd/sd-bus/bus-internal.c
index 0f1ea45c08..a249b848ca 100644
--- a/src/libsystemd/sd-bus/bus-internal.c
+++ b/src/libsystemd/sd-bus/bus-internal.c
@@ -29,10 +29,8 @@ bool object_path_is_valid(const char *p) {
                 } else {
                         bool good;
 
-                        good =
-                                (*q >= 'a' && *q <= 'z') ||
-                                (*q >= 'A' && *q <= 'Z') ||
-                                (*q >= '0' && *q <= '9') ||
+                        good = ascii_isalpha(*q) ||
+                                ascii_isdigit(*q) ||
                                 *q == '_';
 
                         if (!good)
@@ -87,9 +85,8 @@ bool interface_name_is_valid(const char *p) {
                         bool good;
 
                         good =
-                                (*q >= 'a' && *q <= 'z') ||
-                                (*q >= 'A' && *q <= 'Z') ||
-                                (!dot && *q >= '0' && *q <= '9') ||
+                                ascii_isalpha(*q) ||
+                                (!dot && ascii_isdigit(*q)) ||
                                 *q == '_';
 
                         if (!good) {
@@ -134,9 +131,8 @@ bool service_name_is_valid(const char *p) {
                         bool good;
 
                         good =
-                                (*q >= 'a' && *q <= 'z') ||
-                                (*q >= 'A' && *q <= 'Z') ||
-                                ((!dot || unique) && *q >= '0' && *q <= '9') ||
+                                ascii_isalpha(*q) ||
+                                ((!dot || unique) && ascii_isdigit(*q)) ||
                                 IN_SET(*q, '_', '-');
 
                         if (!good)
@@ -167,9 +163,8 @@ bool member_name_is_valid(const char *p) {
                 bool good;
 
                 good =
-                        (*q >= 'a' && *q <= 'z') ||
-                        (*q >= 'A' && *q <= 'Z') ||
-                        (*q >= '0' && *q <= '9') ||
+                        ascii_isalpha(*q) ||
+                        ascii_isdigit(*q) ||
                         *q == '_';
 
                 if (!good)
@@ -301,9 +296,8 @@ char *bus_address_escape(const char *v) {
 
         for (a = v, b = r; *a; a++) {
 
-                if ((*a >= '0' && *a <= '9') ||
-                    (*a >= 'a' && *a <= 'z') ||
-                    (*a >= 'A' && *a <= 'Z') ||
+                if (ascii_isdigit(*a) ||
+                    ascii_isalpha(*a) ||
                     strchr("_-/.", *a))
                         *(b++) = *a;
                 else {
diff --git a/src/libsystemd/sd-device/test-sd-device.c b/src/libsystemd/sd-device/test-sd-device.c
index ba7767ee49..6a03582fd9 100644
--- a/src/libsystemd/sd-device/test-sd-device.c
+++ b/src/libsystemd/sd-device/test-sd-device.c
@@ -171,7 +171,7 @@ static void test_sd_device_one(sd_device *d) {
                 assert_se(val > sysname);
                 assert_se(val < sysname + strlen(sysname));
                 assert_se(in_charset(val, DIGITS));
-                assert_se(!isdigit(val[-1]));
+                assert_se(!ascii_isdigit(val[-1]));
         } else
                 assert_se(r == -ENOENT);
 
diff --git a/src/libsystemd/sd-id128/id128-util.c b/src/libsystemd/sd-id128/id128-util.c
index afdf4b7f98..4f52c14f64 100644
--- a/src/libsystemd/sd-id128/id128-util.c
+++ b/src/libsystemd/sd-id128/id128-util.c
@@ -25,7 +25,7 @@ bool id128_is_valid(const char *s) {
                 for (i = 0; i < l; i++) {
                         char c = s[i];
 
-                        if (!(c >= '0' && c <= '9') &&
+                        if (!ascii_isdigit(c) &&
                             !(c >= 'a' && c <= 'f') &&
                             !(c >= 'A' && c <= 'F'))
                                 return false;
@@ -42,7 +42,7 @@ bool id128_is_valid(const char *s) {
                                 if (c != '-')
                                         return false;
                         } else {
-                                if (!(c >= '0' && c <= '9') &&
+                                if (!ascii_isdigit(c) &&
                                     !(c >= 'a' && c <= 'f') &&
                                     !(c >= 'A' && c <= 'F'))
                                         return false;
diff --git a/src/libsystemd/sd-journal/journal-file.c b/src/libsystemd/sd-journal/journal-file.c
index 976e28e54b..bbe7c78306 100644
--- a/src/libsystemd/sd-journal/journal-file.c
+++ b/src/libsystemd/sd-journal/journal-file.c
@@ -1470,13 +1470,13 @@ bool journal_field_valid(const char *p, size_t l, bool allow_protected) {
                 return false;
 
         /* Don't allow digits as first character */
-        if (p[0] >= '0' && p[0] <= '9')
+        if (ascii_isdigit(p[0]))
                 return false;
 
         /* Only allow A-Z0-9 and '_' */
         for (const char *a = p; a < p + l; a++)
                 if ((*a < 'A' || *a > 'Z') &&
-                    (*a < '0' || *a > '9') &&
+                    !ascii_isdigit(*a) &&
                     *a != '_')
                         return false;
 
diff --git a/src/libsystemd/sd-journal/sd-journal.c b/src/libsystemd/sd-journal/sd-journal.c
index 4a9f1a90b2..60e352022f 100644
--- a/src/libsystemd/sd-journal/sd-journal.c
+++ b/src/libsystemd/sd-journal/sd-journal.c
@@ -167,7 +167,7 @@ static int match_is_valid(const void *data, size_t size) {
                 if (*p >= 'A' && *p <= 'Z')
                         continue;
 
-                if (*p >= '0' && *p <= '9')
+                if (ascii_isdigit(*p))
                         continue;
 
                 return false;
@@ -2246,7 +2246,7 @@ static bool field_is_valid(const char *field) {
                 if (*p >= 'A' && *p <= 'Z')
                         continue;
 
-                if (*p >= '0' && *p <= '9')
+                if (ascii_isdigit(*p))
                         continue;
 
                 return false;
diff --git a/src/login/logind-seat.c b/src/login/logind-seat.c
index 88ff4ce45e..43c72da11f 100644
--- a/src/login/logind-seat.c
+++ b/src/login/logind-seat.c
@@ -646,9 +646,8 @@ void seat_add_to_gc_queue(Seat *s) {
 
 static bool seat_name_valid_char(char c) {
         return
-                (c >= 'a' && c <= 'z') ||
-                (c >= 'A' && c <= 'Z') ||
-                (c >= '0' && c <= '9') ||
+                ascii_isalpha(c) ||
+                ascii_isdigit(c) ||
                 IN_SET(c, '-', '_');
 }
 
diff --git a/src/login/pam_systemd.c b/src/login/pam_systemd.c
index 2047dc1817..cb6a6fb514 100644
--- a/src/login/pam_systemd.c
+++ b/src/login/pam_systemd.c
@@ -195,8 +195,7 @@ static bool display_is_local(const char *display) {
 
         return
                 display[0] == ':' &&
-                display[1] >= '0' &&
-                display[1] <= '9';
+                ascii_isdigit(display[1]);
 }
 
 static int socket_from_display(const char *display) {
diff --git a/src/resolve/resolved-manager.c b/src/resolve/resolved-manager.c
index d2eaea584b..7b83b91bee 100644
--- a/src/resolve/resolved-manager.c
+++ b/src/resolve/resolved-manager.c
@@ -1163,7 +1163,7 @@ static int manager_next_random_name(const char *old, char **ret_new) {
         assert(p);
 
         while (p > old) {
-                if (!strchr(DIGITS, p[-1]))
+                if (!ascii_isdigit(p[-1]))
                         break;
 
                 p--;
diff --git a/src/shared/calendarspec.c b/src/shared/calendarspec.c
index 767c1b7856..86a6d3f608 100644
--- a/src/shared/calendarspec.c
+++ b/src/shared/calendarspec.c
@@ -521,7 +521,7 @@ static int parse_component_decimal(const char **p, bool usec, int *res) {
         const char *e = NULL;
         int r;
 
-        if (!isdigit(**p))
+        if (!ascii_isdigit(**p))
                 return -EINVAL;
 
         r = parse_one_number(*p, &e, &value);
diff --git a/src/shared/device-nodes.c b/src/shared/device-nodes.c
index ec5613ac58..40e469379f 100644
--- a/src/shared/device-nodes.c
+++ b/src/shared/device-nodes.c
@@ -5,13 +5,13 @@
 #include <string.h>
 
 #include "device-nodes.h"
+#include "string-util.h"
 #include "utf8.h"
 
 int allow_listed_char_for_devnode(char c, const char *white) {
         return
-                (c >= '0' && c <= '9') ||
-                (c >= 'A' && c <= 'Z') ||
-                (c >= 'a' && c <= 'z') ||
+                ascii_isdigit(c) ||
+                ascii_isalpha(c) ||
                 strchr("#+-.:=@_", c) ||
                 (white && strchr(white, c));
 }
diff --git a/src/shared/dissect-image.c b/src/shared/dissect-image.c
index 36174f8743..68f7912674 100644
--- a/src/shared/dissect-image.c
+++ b/src/shared/dissect-image.c
@@ -251,7 +251,7 @@ static int make_partition_devname(
         if (isempty(whole_devname)) /* Make sure there *is* a last char */
                 return -EINVAL;
 
-        need_p = strchr(DIGITS, whole_devname[strlen(whole_devname)-1]); /* Last char a digit? */
+        need_p = ascii_isdigit(whole_devname[strlen(whole_devname)-1]); /* Last char a digit? */
 
         return asprintf(ret, "%s%s%i", whole_devname, need_p ? "p" : "", nr);
 }
diff --git a/src/shared/dns-domain.c b/src/shared/dns-domain.c
index 1292a3359f..ebf86d2405 100644
--- a/src/shared/dns-domain.c
+++ b/src/shared/dns-domain.c
@@ -236,9 +236,8 @@ int dns_label_escape(const char *p, size_t l, char *dest, size_t sz) {
                         sz -= 2;
 
                 } else if (IN_SET(*p, '_', '-') ||
-                           (*p >= '0' && *p <= '9') ||
-                           (*p >= 'a' && *p <= 'z') ||
-                           (*p >= 'A' && *p <= 'Z')) {
+                           ascii_isdigit(*p) ||
+                           ascii_isalpha(*p)) {
 
                         /* Proper character */
 
@@ -907,15 +906,13 @@ static bool srv_type_label_is_valid(const char *label, size_t n) {
                 return false;
 
         /* Second char must be a letter */
-        if (!(label[1] >= 'A' && label[1] <= 'Z') &&
-            !(label[1] >= 'a' && label[1] <= 'z'))
+        if (!ascii_isalpha(label[1]))
                 return false;
 
         /* Third and further chars must be alphanumeric or a hyphen */
         for (k = 2; k < n; k++) {
-                if (!(label[k] >= 'A' && label[k] <= 'Z') &&
-                    !(label[k] >= 'a' && label[k] <= 'z') &&
-                    !(label[k] >= '0' && label[k] <= '9') &&
+                if (!ascii_isalpha(label[k]) &&
+                    !ascii_isdigit(label[k]) &&
                     label[k] != '-')
                         return false;
         }
diff --git a/src/udev/udev-builtin-path_id.c b/src/udev/udev-builtin-path_id.c
index ae92e45205..d33eede984 100644
--- a/src/udev/udev-builtin-path_id.c
+++ b/src/udev/udev-builtin-path_id.c
@@ -695,9 +695,8 @@ static int builtin_path_id(sd_device *dev, sd_netlink **rtnl, int argc, char *ar
 
                 /* compose valid udev tag name */
                 for (const char *p = path; *p; p++) {
-                        if ((*p >= '0' && *p <= '9') ||
-                            (*p >= 'A' && *p <= 'Z') ||
-                            (*p >= 'a' && *p <= 'z') ||
+                        if (ascii_isdigit(*p) ||
+                            ascii_isalpha(*p) ||
                             *p == '-') {
                                 tag[i++] = *p;
                                 continue;