1 /* SPDX-License-Identifier: LGPL-2.1+ */
10 #include "alloc-util.h"
13 #include "extract-word.h"
15 #include "parse-util.h"
16 #include "string-util.h"
20 #define VALID_CHARS_ENV_NAME \
25 #define ARG_MAX ((size_t) sysconf(_SC_ARG_MAX))
28 static bool env_name_is_valid_n(const char *e, size_t n) {
37 if (e[0] >= '0' && e[0] <= '9')
40 /* POSIX says the overall size of the environment block cannot
41 * be > ARG_MAX, an individual assignment hence cannot be
42 * either. Discounting the equal sign and trailing NUL this
43 * hence leaves ARG_MAX-2 as longest possible variable
48 for (p = e; p < e + n; p++)
49 if (!strchr(VALID_CHARS_ENV_NAME, *p))
55 bool env_name_is_valid(const char *e) {
59 return env_name_is_valid_n(e, strlen(e));
62 bool env_value_is_valid(const char *e) {
66 if (!utf8_is_valid(e))
69 /* bash allows tabs and newlines in environment variables, and so
71 if (string_has_cc(e, "\t\n"))
74 /* POSIX says the overall size of the environment block cannot
75 * be > ARG_MAX, an individual assignment hence cannot be
76 * either. Discounting the shortest possible variable name of
77 * length 1, the equal sign and trailing NUL this hence leaves
78 * ARG_MAX-3 as longest possible variable value. */
79 if (strlen(e) > ARG_MAX - 3)
85 bool env_assignment_is_valid(const char *e) {
92 if (!env_name_is_valid_n(e, eq - e))
95 if (!env_value_is_valid(eq + 1))
98 /* POSIX says the overall size of the environment block cannot
99 * be > ARG_MAX, hence the individual variable assignments
100 * cannot be either, but let's leave room for one trailing NUL
102 if (strlen(e) > ARG_MAX - 1)
108 #if 0 /// UNNEEDED by elogind
109 bool strv_env_is_valid(char **e) {
115 if (!env_assignment_is_valid(*p))
118 /* Check if there are duplicate assginments */
119 k = strcspn(*p, "=");
120 STRV_FOREACH(q, p + 1)
121 if (strneq(*p, *q, k) && (*q)[k] == '=')
128 bool strv_env_name_is_valid(char **l) {
132 if (!env_name_is_valid(*p))
135 STRV_FOREACH(q, p + 1)
143 bool strv_env_name_or_assignment_is_valid(char **l) {
147 if (!env_assignment_is_valid(*p) && !env_name_is_valid(*p))
150 STRV_FOREACH(q, p + 1)
158 static int env_append(char **r, char ***k, char **a) {
165 /* Add the entries of a to *k unless they already exist in *r
166 * in which case they are overridden instead. This assumes
167 * there is enough space in the r array. */
173 n = strcspn(*a, "=");
178 for (j = r; j < *k; j++)
179 if (strneq(*j, *a, n))
195 char **strv_env_merge(size_t n_lists, ...) {
201 /* Merges an arbitrary number of environment sets */
203 va_start(ap, n_lists);
204 for (i = 0; i < n_lists; i++) {
205 l = va_arg(ap, char**);
216 va_start(ap, n_lists);
217 for (i = 0; i < n_lists; i++) {
218 l = va_arg(ap, char**);
219 if (env_append(r, &k, l) < 0)
235 static bool env_match(const char *t, const char *pattern) {
239 /* pattern a matches string a
244 * a= does not match a
245 * a=b does not match a=
246 * a=b does not match a
247 * a=b does not match a=c */
249 if (streq(t, pattern))
252 if (!strchr(pattern, '=')) {
253 size_t l = strlen(pattern);
255 return strneq(t, pattern, l) && t[l] == '=';
261 static bool env_entry_has_name(const char *entry, const char *name) {
267 t = startswith(entry, name);
274 char **strv_env_delete(char **x, size_t n_lists, ...) {
279 /* Deletes every entry from x that is mentioned in the other
291 va_start(ap, n_lists);
292 for (v = 0; v < n_lists; v++) {
295 l = va_arg(ap, char**);
297 if (env_match(*k, *j))
322 char **strv_env_unset(char **l, const char *p) {
331 /* Drops every occurrence of the env var setting p in the
332 * string list. Edits in-place. */
334 for (f = t = l; *f; f++) {
336 if (env_match(*f, p)) {
348 char **strv_env_unset_many(char **l, ...) {
355 /* Like strv_env_unset() but applies many at once. Edits in-place. */
357 for (f = t = l; *f; f++) {
364 while ((p = va_arg(ap, const char*))) {
365 if (env_match(*f, p)) {
385 int strv_env_replace(char ***l, char *p) {
387 const char *t, *name;
391 /* Replace first occurrence of the env var or add a new one in the
392 * string list. Drop other occurences. Edits in-place. Does not copy p.
393 * p must be a valid key=value assignment.
399 name = strndupa(p, t - p);
401 for (f = *l; f && *f; f++)
402 if (env_entry_has_name(*f, name)) {
403 free_and_replace(*f, p);
404 strv_env_unset(f + 1, *f);
408 /* We didn't find a match, we need to append p or create a new strv */
409 if (strv_push(l, p) < 0)
414 char **strv_env_set(char **x, const char *p) {
417 _cleanup_strv_free_ char **r = NULL;
418 char* m[2] = { (char*) p, NULL };
420 /* Overrides the env var setting of p, returns a new copy */
422 r = new(char*, strv_length(x)+2);
427 if (env_append(r, &k, x) < 0)
430 if (env_append(r, &k, m) < 0)
438 char *strv_env_get_n(char **l, const char *name, size_t k, unsigned flags) {
446 STRV_FOREACH_BACKWARDS(i, l)
447 if (strneq(*i, name, k) &&
451 if (flags & REPLACE_ENV_USE_ENVIRONMENT) {
454 t = strndupa(name, k);
461 char *strv_env_get(char **l, const char *name) {
464 return strv_env_get_n(l, name, strlen(name), 0);
467 char **strv_env_clean_with_callback(char **e, void (*invalid_callback)(const char *p, void *userdata), void *userdata) {
473 bool duplicate = false;
475 if (!env_assignment_is_valid(*p)) {
476 if (invalid_callback)
477 invalid_callback(*p, userdata);
482 n = strcspn(*p, "=");
483 STRV_FOREACH(q, p + 1)
484 if (strneq(*p, *q, n) && (*q)[n] == '=') {
503 char *replace_env_n(const char *format, size_t n, char **env, unsigned flags) {
514 const char *e, *word = format, *test_value;
516 _cleanup_free_ char *r = NULL;
522 for (e = format, i = 0; *e && i < n; e ++, i ++)
532 k = strnappend(r, word, e-word-1);
536 free_and_replace(r, k);
541 } else if (*e == '$') {
542 k = strnappend(r, word, e-word);
546 free_and_replace(r, k);
551 } else if (flags & REPLACE_ENV_ALLOW_BRACELESS && strchr(VALID_CHARS_ENV_NAME, *e)) {
552 k = strnappend(r, word, e-word-1);
556 free_and_replace(r, k);
559 state = VARIABLE_RAW;
569 t = strv_env_get_n(env, word+2, e-word-2, flags);
575 free_and_replace(r, k);
579 } else if (*e == ':') {
580 if (!(flags & REPLACE_ENV_ALLOW_EXTENDED))
581 /* Treat this as unsupported syntax, i.e. do no replacement */
592 state = DEFAULT_VALUE;
594 state = ALTERNATE_VALUE;
603 case DEFAULT_VALUE: /* fall through */
604 case ALTERNATE_VALUE:
605 assert(flags & REPLACE_ENV_ALLOW_EXTENDED);
618 _cleanup_free_ char *v = NULL;
620 t = strv_env_get_n(env, word+2, len, flags);
622 if (t && state == ALTERNATE_VALUE)
623 t = v = replace_env_n(test_value, e-test_value, env, flags);
624 else if (!t && state == DEFAULT_VALUE)
625 t = v = replace_env_n(test_value, e-test_value, env, flags);
631 free_and_replace(r, k);
639 assert(flags & REPLACE_ENV_ALLOW_BRACELESS);
641 if (!strchr(VALID_CHARS_ENV_NAME, *e)) {
644 t = strv_env_get_n(env, word+1, e-word-1, flags);
650 free_and_replace(r, k);
659 if (state == VARIABLE_RAW) {
662 assert(flags & REPLACE_ENV_ALLOW_BRACELESS);
664 t = strv_env_get_n(env, word+1, e-word-1, flags);
665 return strappend(r, t);
667 return strnappend(r, word, e-word);
670 char **replace_env_argv(char **argv, char **env) {
674 l = strv_length(argv);
676 ret = new(char*, l+1);
680 STRV_FOREACH(i, argv) {
682 /* If $FOO appears as single word, replace it by the split up variable */
683 if ((*i)[0] == '$' && !IN_SET((*i)[1], '{', '$')) {
685 char **w, **m = NULL;
688 e = strv_env_get(env, *i+1);
692 r = strv_split_extract(&m, e, WHITESPACE, EXTRACT_RELAX|EXTRACT_QUOTES);
704 w = reallocarray(ret, l + 1, sizeof(char *));
714 memcpy(ret + k, m, q * sizeof(char*));
722 /* If ${FOO} appears as part of a word, replace it by the variable as-is */
723 ret[k] = replace_env(*i, env, 0);
736 int getenv_bool(const char *p) {
743 return parse_boolean(e);
746 #if 0 /// UNNEEDED by elogind
747 int getenv_bool_secure(const char *p) {
750 e = secure_getenv(p);
754 return parse_boolean(e);
757 int serialize_environment(FILE *f, char **environment) {
760 STRV_FOREACH(e, environment) {
761 _cleanup_free_ char *ce;
767 fprintf(f, "env=%s\n", ce);
770 /* caller should call ferror() */
775 int deserialize_environment(char ***environment, const char *line) {
782 assert(startswith(line, "env="));
783 r = cunescape(line + 4, 0, &uce);
787 return strv_env_replace(environment, uce);