1 files changed, 111 insertions, 0 deletions
diff --git a/collectors/log2journal/log2journal-replace.c b/collectors/log2journal/log2journal-replace.c
new file mode 100644
index 00000000..429d615d
--- /dev/null
+++ b/collectors/log2journal/log2journal-replace.c
@@ -0,0 +1,111 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "log2journal.h"
+
+void replace_node_free(REPLACE_NODE *rpn) {
+    hashed_key_cleanup(&rpn->name);
+    rpn->next = NULL;
+    freez(rpn);
+}
+
+void replace_pattern_cleanup(REPLACE_PATTERN *rp) {
+    if(rp->pattern) {
+        freez((void *)rp->pattern);
+        rp->pattern = NULL;
+    }
+
+    while(rp->nodes) {
+        REPLACE_NODE *rpn = rp->nodes;
+        rp->nodes = rpn->next;
+        replace_node_free(rpn);
+    }
+}
+
+static REPLACE_NODE *replace_pattern_add_node(REPLACE_NODE **head, bool is_variable, const char *text) {
+    REPLACE_NODE *new_node = callocz(1, sizeof(REPLACE_NODE));
+    if (!new_node)
+        return NULL;
+
+    hashed_key_set(&new_node->name, text);
+    new_node->is_variable = is_variable;
+    new_node->next = NULL;
+
+    if (*head == NULL)
+        *head = new_node;
+
+    else {
+        REPLACE_NODE *current = *head;
+
+        // append it
+        while (current->next != NULL)
+            current = current->next;
+
+        current->next = new_node;
+    }
+
+    return new_node;
+}
+
+bool replace_pattern_set(REPLACE_PATTERN *rp, const char *pattern) {
+    replace_pattern_cleanup(rp);
+
+    rp->pattern = strdupz(pattern);
+    const char *current = rp->pattern;
+
+    while (*current != '\0') {
+        if (*current == '$' && *(current + 1) == '{') {
+            // Start of a variable
+            const char *end = strchr(current, '}');
+            if (!end) {
+                log2stderr("Error: Missing closing brace in replacement pattern: %s", rp->pattern);
+                return false;
+            }
+
+            size_t name_length = end - current - 2; // Length of the variable name
+            char *variable_name = strndupz(current + 2, name_length);
+            if (!variable_name) {
+                log2stderr("Error: Memory allocation failed for variable name.");
+                return false;
+            }
+
+            REPLACE_NODE *node = replace_pattern_add_node(&(rp->nodes), true, variable_name);
+            if (!node) {
+                freez(variable_name);
+                log2stderr("Error: Failed to add replacement node for variable.");
+                return false;
+            }
+
+            current = end + 1; // Move past the variable
+        }
+        else {
+            // Start of literal text
+            const char *start = current;
+            while (*current != '\0' && !(*current == '$' && *(current + 1) == '{')) {
+                current++;
+            }
+
+            size_t text_length = current - start;
+            char *text = strndupz(start, text_length);
+            if (!text) {
+                log2stderr("Error: Memory allocation failed for literal text.");
+                return false;
+            }
+
+            REPLACE_NODE *node = replace_pattern_add_node(&(rp->nodes), false, text);
+            if (!node) {
+                freez(text);
+                log2stderr("Error: Failed to add replacement node for text.");
+                return false;
+            }
+        }
+    }
+
+    for(REPLACE_NODE *node = rp->nodes; node; node = node->next) {
+        if(node->is_variable) {
+            rp->has_variables = true;
+            break;
+        }
+    }
+
+    return true;
+}