1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 Copyright 2012 Lennart Poettering
13 #include "alloc-util.h"
16 #include "extract-word.h"
18 #include "parse-util.h"
19 #include "string-util.h"
23 #define VALID_CHARS_ENV_NAME \
28 #define ARG_MAX ((size_t) sysconf(_SC_ARG_MAX))
31 static bool env_name_is_valid_n(const char *e, size_t n) {
40 if (e[0] >= '0' && e[0] <= '9')
43 /* POSIX says the overall size of the environment block cannot
44 * be > ARG_MAX, an individual assignment hence cannot be
45 * either. Discounting the equal sign and trailing NUL this
46 * hence leaves ARG_MAX-2 as longest possible variable
51 for (p = e; p < e + n; p++)
52 if (!strchr(VALID_CHARS_ENV_NAME, *p))
58 bool env_name_is_valid(const char *e) {
62 return env_name_is_valid_n(e, strlen(e));
65 bool env_value_is_valid(const char *e) {
69 if (!utf8_is_valid(e))
72 /* bash allows tabs and newlines in environment variables, and so
74 if (string_has_cc(e, "\t\n"))
77 /* POSIX says the overall size of the environment block cannot
78 * be > ARG_MAX, an individual assignment hence cannot be
79 * either. Discounting the shortest possible variable name of
80 * length 1, the equal sign and trailing NUL this hence leaves
81 * ARG_MAX-3 as longest possible variable value. */
82 if (strlen(e) > ARG_MAX - 3)
88 bool env_assignment_is_valid(const char *e) {
95 if (!env_name_is_valid_n(e, eq - e))
98 if (!env_value_is_valid(eq + 1))
101 /* POSIX says the overall size of the environment block cannot
102 * be > ARG_MAX, hence the individual variable assignments
103 * cannot be either, but let's leave room for one trailing NUL
105 if (strlen(e) > ARG_MAX - 1)
111 #if 0 /// UNNEEDED by elogind
112 bool strv_env_is_valid(char **e) {
118 if (!env_assignment_is_valid(*p))
121 /* Check if there are duplicate assginments */
122 k = strcspn(*p, "=");
123 STRV_FOREACH(q, p + 1)
124 if (strneq(*p, *q, k) && (*q)[k] == '=')
131 bool strv_env_name_is_valid(char **l) {
135 if (!env_name_is_valid(*p))
138 STRV_FOREACH(q, p + 1)
146 bool strv_env_name_or_assignment_is_valid(char **l) {
150 if (!env_assignment_is_valid(*p) && !env_name_is_valid(*p))
153 STRV_FOREACH(q, p + 1)
161 static int env_append(char **r, char ***k, char **a) {
168 /* Add the entries of a to *k unless they already exist in *r
169 * in which case they are overridden instead. This assumes
170 * there is enough space in the r array. */
176 n = strcspn(*a, "=");
181 for (j = r; j < *k; j++)
182 if (strneq(*j, *a, n))
198 char **strv_env_merge(size_t n_lists, ...) {
204 /* Merges an arbitrary number of environment sets */
206 va_start(ap, n_lists);
207 for (i = 0; i < n_lists; i++) {
208 l = va_arg(ap, char**);
219 va_start(ap, n_lists);
220 for (i = 0; i < n_lists; i++) {
221 l = va_arg(ap, char**);
222 if (env_append(r, &k, l) < 0)
238 static bool env_match(const char *t, const char *pattern) {
242 /* pattern a matches string a
247 * a= does not match a
248 * a=b does not match a=
249 * a=b does not match a
250 * a=b does not match a=c */
252 if (streq(t, pattern))
255 if (!strchr(pattern, '=')) {
256 size_t l = strlen(pattern);
258 return strneq(t, pattern, l) && t[l] == '=';
264 static bool env_entry_has_name(const char *entry, const char *name) {
270 t = startswith(entry, name);
277 char **strv_env_delete(char **x, size_t n_lists, ...) {
282 /* Deletes every entry from x that is mentioned in the other
294 va_start(ap, n_lists);
295 for (v = 0; v < n_lists; v++) {
298 l = va_arg(ap, char**);
300 if (env_match(*k, *j))
325 char **strv_env_unset(char **l, const char *p) {
334 /* Drops every occurrence of the env var setting p in the
335 * string list. Edits in-place. */
337 for (f = t = l; *f; f++) {
339 if (env_match(*f, p)) {
351 char **strv_env_unset_many(char **l, ...) {
358 /* Like strv_env_unset() but applies many at once. Edits in-place. */
360 for (f = t = l; *f; f++) {
367 while ((p = va_arg(ap, const char*))) {
368 if (env_match(*f, p)) {
388 int strv_env_replace(char ***l, char *p) {
390 const char *t, *name;
394 /* Replace first occurrence of the env var or add a new one in the
395 * string list. Drop other occurences. Edits in-place. Does not copy p.
396 * p must be a valid key=value assignment.
402 name = strndupa(p, t - p);
404 for (f = *l; f && *f; f++)
405 if (env_entry_has_name(*f, name)) {
406 free_and_replace(*f, p);
407 strv_env_unset(f + 1, *f);
411 /* We didn't find a match, we need to append p or create a new strv */
412 if (strv_push(l, p) < 0)
417 char **strv_env_set(char **x, const char *p) {
420 _cleanup_strv_free_ char **r = NULL;
421 char* m[2] = { (char*) p, NULL };
423 /* Overrides the env var setting of p, returns a new copy */
425 r = new(char*, strv_length(x)+2);
430 if (env_append(r, &k, x) < 0)
433 if (env_append(r, &k, m) < 0)
441 char *strv_env_get_n(char **l, const char *name, size_t k, unsigned flags) {
449 STRV_FOREACH_BACKWARDS(i, l)
450 if (strneq(*i, name, k) &&
454 if (flags & REPLACE_ENV_USE_ENVIRONMENT) {
457 t = strndupa(name, k);
464 char *strv_env_get(char **l, const char *name) {
467 return strv_env_get_n(l, name, strlen(name), 0);
470 char **strv_env_clean_with_callback(char **e, void (*invalid_callback)(const char *p, void *userdata), void *userdata) {
476 bool duplicate = false;
478 if (!env_assignment_is_valid(*p)) {
479 if (invalid_callback)
480 invalid_callback(*p, userdata);
485 n = strcspn(*p, "=");
486 STRV_FOREACH(q, p + 1)
487 if (strneq(*p, *q, n) && (*q)[n] == '=') {
506 char *replace_env_n(const char *format, size_t n, char **env, unsigned flags) {
517 const char *e, *word = format, *test_value;
519 _cleanup_free_ char *r = NULL;
525 for (e = format, i = 0; *e && i < n; e ++, i ++)
535 k = strnappend(r, word, e-word-1);
539 free_and_replace(r, k);
544 } else if (*e == '$') {
545 k = strnappend(r, word, e-word);
549 free_and_replace(r, k);
554 } else if (flags & REPLACE_ENV_ALLOW_BRACELESS && strchr(VALID_CHARS_ENV_NAME, *e)) {
555 k = strnappend(r, word, e-word-1);
559 free_and_replace(r, k);
562 state = VARIABLE_RAW;
572 t = strv_env_get_n(env, word+2, e-word-2, flags);
578 free_and_replace(r, k);
582 } else if (*e == ':') {
583 if (!(flags & REPLACE_ENV_ALLOW_EXTENDED))
584 /* Treat this as unsupported syntax, i.e. do no replacement */
595 state = DEFAULT_VALUE;
597 state = ALTERNATE_VALUE;
606 case DEFAULT_VALUE: /* fall through */
607 case ALTERNATE_VALUE:
608 assert(flags & REPLACE_ENV_ALLOW_EXTENDED);
621 _cleanup_free_ char *v = NULL;
623 t = strv_env_get_n(env, word+2, len, flags);
625 if (t && state == ALTERNATE_VALUE)
626 t = v = replace_env_n(test_value, e-test_value, env, flags);
627 else if (!t && state == DEFAULT_VALUE)
628 t = v = replace_env_n(test_value, e-test_value, env, flags);
634 free_and_replace(r, k);
642 assert(flags & REPLACE_ENV_ALLOW_BRACELESS);
644 if (!strchr(VALID_CHARS_ENV_NAME, *e)) {
647 t = strv_env_get_n(env, word+1, e-word-1, flags);
653 free_and_replace(r, k);
662 if (state == VARIABLE_RAW) {
665 assert(flags & REPLACE_ENV_ALLOW_BRACELESS);
667 t = strv_env_get_n(env, word+1, e-word-1, flags);
668 return strappend(r, t);
670 return strnappend(r, word, e-word);
673 char **replace_env_argv(char **argv, char **env) {
677 l = strv_length(argv);
679 ret = new(char*, l+1);
683 STRV_FOREACH(i, argv) {
685 /* If $FOO appears as single word, replace it by the split up variable */
686 if ((*i)[0] == '$' && !IN_SET((*i)[1], '{', '$')) {
688 char **w, **m = NULL;
691 e = strv_env_get(env, *i+1);
695 r = strv_split_extract(&m, e, WHITESPACE, EXTRACT_RELAX|EXTRACT_QUOTES);
707 w = reallocarray(ret, l + 1, sizeof(char *));
717 memcpy(ret + k, m, q * sizeof(char*));
725 /* If ${FOO} appears as part of a word, replace it by the variable as-is */
726 ret[k] = replace_env(*i, env, 0);
739 int getenv_bool(const char *p) {
746 return parse_boolean(e);
749 #if 0 /// UNNEEDED by elogind
750 int getenv_bool_secure(const char *p) {
753 e = secure_getenv(p);
757 return parse_boolean(e);
760 int serialize_environment(FILE *f, char **environment) {
763 STRV_FOREACH(e, environment) {
764 _cleanup_free_ char *ce;
770 fprintf(f, "env=%s\n", ce);
773 /* caller should call ferror() */
778 int deserialize_environment(char ***environment, const char *line) {
785 assert(startswith(line, "env="));
786 r = cunescape(line + 4, 0, &uce);
790 return strv_env_replace(environment, uce);