Merge pull request #160 from kaysievers/libsplit

build-sys: split internal basic/ library from shared/

1 files changed, 594 insertions, 0 deletions

diff --git a/src/basic/env-util.c b/src/basic/env-util.c
new file mode 100644
index 0000000000..ac7bbdc711
--- /dev/null
+++ b/src/basic/env-util.c
@@ -0,0 +1,594 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2012 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <limits.h>
+#include <unistd.h>
+
+#include "strv.h"
+#include "utf8.h"
+#include "util.h"
+#include "env-util.h"
+#include "def.h"
+
+#define VALID_CHARS_ENV_NAME                    \
+        DIGITS LETTERS                          \
+        "_"
+
+#ifndef ARG_MAX
+#define ARG_MAX ((size_t) sysconf(_SC_ARG_MAX))
+#endif
+
+static bool env_name_is_valid_n(const char *e, size_t n) {
+        const char *p;
+
+        if (!e)
+                return false;
+
+        if (n <= 0)
+                return false;
+
+        if (e[0] >= '0' && e[0] <= '9')
+                return false;
+
+        /* POSIX says the overall size of the environment block cannot
+         * be > ARG_MAX, an individual assignment hence cannot be
+         * either. Discounting the equal sign and trailing NUL this
+         * hence leaves ARG_MAX-2 as longest possible variable
+         * name. */
+        if (n > ARG_MAX - 2)
+                return false;
+
+        for (p = e; p < e + n; p++)
+                if (!strchr(VALID_CHARS_ENV_NAME, *p))
+                        return false;
+
+        return true;
+}
+
+bool env_name_is_valid(const char *e) {
+        if (!e)
+                return false;
+
+        return env_name_is_valid_n(e, strlen(e));
+}
+
+bool env_value_is_valid(const char *e) {
+        if (!e)
+                return false;
+
+        if (!utf8_is_valid(e))
+                return false;
+
+        /* bash allows tabs in environment variables, and so should
+         * we */
+        if (string_has_cc(e, "\t"))
+                return false;
+
+        /* POSIX says the overall size of the environment block cannot
+         * be > ARG_MAX, an individual assignment hence cannot be
+         * either. Discounting the shortest possible variable name of
+         * length 1, the equal sign and trailing NUL this hence leaves
+         * ARG_MAX-3 as longest possible variable value. */
+        if (strlen(e) > ARG_MAX - 3)
+                return false;
+
+        return true;
+}
+
+bool env_assignment_is_valid(const char *e) {
+        const char *eq;
+
+        eq = strchr(e, '=');
+        if (!eq)
+                return false;
+
+        if (!env_name_is_valid_n(e, eq - e))
+                return false;
+
+        if (!env_value_is_valid(eq + 1))
+                return false;
+
+        /* POSIX says the overall size of the environment block cannot
+         * be > ARG_MAX, hence the individual variable assignments
+         * cannot be either, but let's leave room for one trailing NUL
+         * byte. */
+        if (strlen(e) > ARG_MAX - 1)
+                return false;
+
+        return true;
+}
+
+bool strv_env_is_valid(char **e) {
+        char **p, **q;
+
+        STRV_FOREACH(p, e) {
+                size_t k;
+
+                if (!env_assignment_is_valid(*p))
+                        return false;
+
+                /* Check if there are duplicate assginments */
+                k = strcspn(*p, "=");
+                STRV_FOREACH(q, p + 1)
+                        if (strneq(*p, *q, k) && (*q)[k] == '=')
+                                return false;
+        }
+
+        return true;
+}
+
+bool strv_env_name_or_assignment_is_valid(char **l) {
+        char **p, **q;
+
+        STRV_FOREACH(p, l) {
+                if (!env_assignment_is_valid(*p) && !env_name_is_valid(*p))
+                        return false;
+
+                STRV_FOREACH(q, p + 1)
+                        if (streq(*p, *q))
+                                return false;
+        }
+
+        return true;
+}
+
+static int env_append(char **r, char ***k, char **a) {
+        assert(r);
+        assert(k);
+
+        if (!a)
+                return 0;
+
+        /* Add the entries of a to *k unless they already exist in *r
+         * in which case they are overridden instead. This assumes
+         * there is enough space in the r array. */
+
+        for (; *a; a++) {
+                char **j;
+                size_t n;
+
+                n = strcspn(*a, "=");
+
+                if ((*a)[n] == '=')
+                        n++;
+
+                for (j = r; j < *k; j++)
+                        if (strneq(*j, *a, n))
+                                break;
+
+                if (j >= *k)
+                        (*k)++;
+                else
+                        free(*j);
+
+                *j = strdup(*a);
+                if (!*j)
+                        return -ENOMEM;
+        }
+
+        return 0;
+}
+
+char **strv_env_merge(unsigned n_lists, ...) {
+        size_t n = 0;
+        char **l, **k, **r;
+        va_list ap;
+        unsigned i;
+
+        /* Merges an arbitrary number of environment sets */
+
+        va_start(ap, n_lists);
+        for (i = 0; i < n_lists; i++) {
+                l = va_arg(ap, char**);
+                n += strv_length(l);
+        }
+        va_end(ap);
+
+        r = new(char*, n+1);
+        if (!r)
+                return NULL;
+
+        k = r;
+
+        va_start(ap, n_lists);
+        for (i = 0; i < n_lists; i++) {
+                l = va_arg(ap, char**);
+                if (env_append(r, &k, l) < 0)
+                        goto fail;
+        }
+        va_end(ap);
+
+        *k = NULL;
+
+        return r;
+
+fail:
+        va_end(ap);
+        strv_free(r);
+
+        return NULL;
+}
+
+_pure_ static bool env_match(const char *t, const char *pattern) {
+        assert(t);
+        assert(pattern);
+
+        /* pattern a matches string a
+         *         a matches a=
+         *         a matches a=b
+         *         a= matches a=
+         *         a=b matches a=b
+         *         a= does not match a
+         *         a=b does not match a=
+         *         a=b does not match a
+         *         a=b does not match a=c */
+
+        if (streq(t, pattern))
+                return true;
+
+        if (!strchr(pattern, '=')) {
+                size_t l = strlen(pattern);
+
+                return strneq(t, pattern, l) && t[l] == '=';
+        }
+
+        return false;
+}
+
+char **strv_env_delete(char **x, unsigned n_lists, ...) {
+        size_t n, i = 0;
+        char **k, **r;
+        va_list ap;
+
+        /* Deletes every entry from x that is mentioned in the other
+         * string lists */
+
+        n = strv_length(x);
+
+        r = new(char*, n+1);
+        if (!r)
+                return NULL;
+
+        STRV_FOREACH(k, x) {
+                unsigned v;
+
+                va_start(ap, n_lists);
+                for (v = 0; v < n_lists; v++) {
+                        char **l, **j;
+
+                        l = va_arg(ap, char**);
+                        STRV_FOREACH(j, l)
+                                if (env_match(*k, *j))
+                                        goto skip;
+                }
+                va_end(ap);
+
+                r[i] = strdup(*k);
+                if (!r[i]) {
+                        strv_free(r);
+                        return NULL;
+                }
+
+                i++;
+                continue;
+
+        skip:
+                va_end(ap);
+        }
+
+        r[i] = NULL;
+
+        assert(i <= n);
+
+        return r;
+}
+
+char **strv_env_unset(char **l, const char *p) {
+
+        char **f, **t;
+
+        if (!l)
+                return NULL;
+
+        assert(p);
+
+        /* Drops every occurrence of the env var setting p in the
+         * string list. Edits in-place. */
+
+        for (f = t = l; *f; f++) {
+
+                if (env_match(*f, p)) {
+                        free(*f);
+                        continue;
+                }
+
+                *(t++) = *f;
+        }
+
+        *t = NULL;
+        return l;
+}
+
+char **strv_env_unset_many(char **l, ...) {
+
+        char **f, **t;
+
+        if (!l)
+                return NULL;
+
+        /* Like strv_env_unset() but applies many at once. Edits in-place. */
+
+        for (f = t = l; *f; f++) {
+                bool found = false;
+                const char *p;
+                va_list ap;
+
+                va_start(ap, l);
+
+                while ((p = va_arg(ap, const char*))) {
+                        if (env_match(*f, p)) {
+                                found = true;
+                                break;
+                        }
+                }
+
+                va_end(ap);
+
+                if (found) {
+                        free(*f);
+                        continue;
+                }
+
+                *(t++) = *f;
+        }
+
+        *t = NULL;
+        return l;
+}
+
+char **strv_env_set(char **x, const char *p) {
+
+        char **k, **r;
+        char* m[2] = { (char*) p, NULL };
+
+        /* Overrides the env var setting of p, returns a new copy */
+
+        r = new(char*, strv_length(x)+2);
+        if (!r)
+                return NULL;
+
+        k = r;
+        if (env_append(r, &k, x) < 0)
+                goto fail;
+
+        if (env_append(r, &k, m) < 0)
+                goto fail;
+
+        *k = NULL;
+
+        return r;
+
+fail:
+        strv_free(r);
+        return NULL;
+}
+
+char *strv_env_get_n(char **l, const char *name, size_t k) {
+        char **i;
+
+        assert(name);
+
+        if (k <= 0)
+                return NULL;
+
+        STRV_FOREACH(i, l)
+                if (strneq(*i, name, k) &&
+                    (*i)[k] == '=')
+                        return *i + k + 1;
+
+        return NULL;
+}
+
+char *strv_env_get(char **l, const char *name) {
+        assert(name);
+
+        return strv_env_get_n(l, name, strlen(name));
+}
+
+char **strv_env_clean_with_callback(char **e, void (*invalid_callback)(const char *p, void *userdata), void *userdata) {
+        char **p, **q;
+        int k = 0;
+
+        STRV_FOREACH(p, e) {
+                size_t n;
+                bool duplicate = false;
+
+                if (!env_assignment_is_valid(*p)) {
+                        if (invalid_callback)
+                                invalid_callback(*p, userdata);
+                        free(*p);
+                        continue;
+                }
+
+                n = strcspn(*p, "=");
+                STRV_FOREACH(q, p + 1)
+                        if (strneq(*p, *q, n) && (*q)[n] == '=') {
+                                duplicate = true;
+                                break;
+                        }
+
+                if (duplicate) {
+                        free(*p);
+                        continue;
+                }
+
+                e[k++] = *p;
+        }
+
+        if (e)
+                e[k] = NULL;
+
+        return e;
+}
+
+char *replace_env(const char *format, char **env) {
+        enum {
+                WORD,
+                CURLY,
+                VARIABLE
+        } state = WORD;
+
+        const char *e, *word = format;
+        char *r = NULL, *k;
+
+        assert(format);
+
+        for (e = format; *e; e ++) {
+
+                switch (state) {
+
+                case WORD:
+                        if (*e == '$')
+                                state = CURLY;
+                        break;
+
+                case CURLY:
+                        if (*e == '{') {
+                                k = strnappend(r, word, e-word-1);
+                                if (!k)
+                                        goto fail;
+
+                                free(r);
+                                r = k;
+
+                                word = e-1;
+                                state = VARIABLE;
+
+                        } else if (*e == '$') {
+                                k = strnappend(r, word, e-word);
+                                if (!k)
+                                        goto fail;
+
+                                free(r);
+                                r = k;
+
+                                word = e+1;
+                                state = WORD;
+                        } else
+                                state = WORD;
+                        break;
+
+                case VARIABLE:
+                        if (*e == '}') {
+                                const char *t;
+
+                                t = strempty(strv_env_get_n(env, word+2, e-word-2));
+
+                                k = strappend(r, t);
+                                if (!k)
+                                        goto fail;
+
+                                free(r);
+                                r = k;
+
+                                word = e+1;
+                                state = WORD;
+                        }
+                        break;
+                }
+        }
+
+        k = strnappend(r, word, e-word);
+        if (!k)
+                goto fail;
+
+        free(r);
+        return k;
+
+fail:
+        free(r);
+        return NULL;
+}
+
+char **replace_env_argv(char **argv, char **env) {
+        char **ret, **i;
+        unsigned k = 0, l = 0;
+
+        l = strv_length(argv);
+
+        ret = new(char*, l+1);
+        if (!ret)
+                return NULL;
+
+        STRV_FOREACH(i, argv) {
+
+                /* If $FOO appears as single word, replace it by the split up variable */
+                if ((*i)[0] == '$' && (*i)[1] != '{') {
+                        char *e;
+                        char **w, **m = NULL;
+                        unsigned q;
+
+                        e = strv_env_get(env, *i+1);
+                        if (e) {
+                                int r;
+
+                                r = strv_split_quoted(&m, e, UNQUOTE_RELAX);
+                                if (r < 0) {
+                                        ret[k] = NULL;
+                                        strv_free(ret);
+                                        return NULL;
+                                }
+                        } else
+                                m = NULL;
+
+                        q = strv_length(m);
+                        l = l + q - 1;
+
+                        w = realloc(ret, sizeof(char*) * (l+1));
+                        if (!w) {
+                                ret[k] = NULL;
+                                strv_free(ret);
+                                strv_free(m);
+                                return NULL;
+                        }
+
+                        ret = w;
+                        if (m) {
+                                memcpy(ret + k, m, q * sizeof(char*));
+                                free(m);
+                        }
+
+                        k += q;
+                        continue;
+                }
+
+                /* If ${FOO} appears as part of a word, replace it by the variable as-is */
+                ret[k] = replace_env(*i, env);
+                if (!ret[k]) {
+                        strv_free(ret);
+                        return NULL;
+                }
+                k++;
+        }
+
+        ret[k] = NULL;
+        return ret;
+}