1 files changed, 144 insertions, 0 deletions
diff --git a/src/shared/env-util.c b/src/shared/env-util.c
index 00c2cdd8c4..ac7bbdc711 100644
--- a/src/shared/env-util.c
+++ b/src/shared/env-util.c
@@ -448,3 +448,147 @@ char **strv_env_clean_with_callback(char **e, void (*invalid_callback)(const cha
 
         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;
+}