Move ap_resolve_env to core.c, in preparation for adding mod_define-like

variable support.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1061444 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 89 insertions, 0 deletions

diff --git a/server/core.c b/server/core.c
index 88cf84b7fd..a9cf7d4686 100644
--- a/server/core.c
+++ b/server/core.c
@@ -1087,6 +1087,95 @@ static const char *set_access_name(cmd_parms *cmd, void *dummy,
     return NULL;
 }
 
+/* Check a string for any ${ENV} environment variable
+ * construct and replace each them by the value of
+ * that environment variable, if it exists. If the
+ * environment value does not exist, leave the ${ENV}
+ * construct alone; it means something else.
+ */
+AP_DECLARE(const char *) ap_resolve_env(apr_pool_t *p, const char * word)
+{
+# define SMALL_EXPANSION 5
+    struct sll {
+        struct sll *next;
+        const char *string;
+        apr_size_t len;
+    } *result, *current, sresult[SMALL_EXPANSION];
+    char *res_buf, *cp;
+    const char *s, *e, *ep;
+    unsigned spc;
+    apr_size_t outlen;
+
+    s = ap_strchr_c(word, '$');
+    if (!s) {
+        return word;
+    }
+
+    /* well, actually something to do */
+    ep = word + strlen(word);
+    spc = 0;
+    result = current = &(sresult[spc++]);
+    current->next = NULL;
+    current->string = word;
+    current->len = s - word;
+    outlen = current->len;
+
+    do {
+        /* prepare next entry */
+        if (current->len) {
+            current->next = (spc < SMALL_EXPANSION)
+                            ? &(sresult[spc++])
+                            : (struct sll *)apr_palloc(p,
+                                                       sizeof(*current->next));
+            current = current->next;
+            current->next = NULL;
+            current->len = 0;
+        }
+
+        if (*s == '$') {
+            if (s[1] == '{' && (e = ap_strchr_c(s, '}'))) {
+                word = getenv(apr_pstrndup(p, s+2, e-s-2));
+                if (word) {
+                    current->string = word;
+                    current->len = strlen(word);
+                    outlen += current->len;
+                }
+                else {
+                    current->string = s;
+                    current->len = e - s + 1;
+                    outlen += current->len;
+                }
+                s = e + 1;
+            }
+            else {
+                current->string = s++;
+                current->len = 1;
+                ++outlen;
+            }
+        }
+        else {
+            word = s;
+            s = ap_strchr_c(s, '$');
+            current->string = word;
+            current->len = s ? s - word : ep - word;
+            outlen += current->len;
+        }
+    } while (s && *s);
+
+    /* assemble result */
+    res_buf = cp = apr_palloc(p, outlen + 1);
+    do {
+        if (result->len) {
+            memcpy(cp, result->string, result->len);
+            cp += result->len;
+        }
+        result = result->next;
+    } while (result);
+    res_buf[outlen] = '\0';
+
+    return res_buf;
+}
+
 static int reset_config_defines(void *dummy)
 {
     ap_server_config_defines = saved_server_config_defines;