reading tree example

main.cpp

@@ -1,15 +1,14 @@
 #include <iostream>
 #include <exception>
 #include <augeas.h>
-
+#include <stdio.h>
+#include <vector>
+#include <map>
 // This file is currently for testing and training using augeas with C++
 // https://github.com/hercules-team/augeas/blob/master/tests/test-api.c
 
 static const char *abs_top_srcdir;
-
 static const char *root = "../root";
-
-// Puth the Augeas lens path here
 static const char *loadpath = "/opt/homebrew/share/augeas/lenses/dist";
 
 
@@ -37,21 +36,6 @@ static void readHostsFile() {
     char *etc_hosts_fn = NULL;
     FILE *hosts_fp = NULL;
     char *hosts_txt = NULL;
-    int readsz = 0;
-
-    /* Read the original contents of the etc/hosts file */
-    if (asprintf(&etc_hosts_fn, "%s/etc/hosts", root) >= 0) {
-        hosts_fp = fopen(etc_hosts_fn, "r");
-        if (hosts_fp) {
-            hosts_txt = static_cast<char *>(calloc(sizeof(char), 4096));
-            if (hosts_txt) {
-                readsz = fread(hosts_txt, sizeof(char), 4096, hosts_fp);
-                *(hosts_txt + readsz) = '\0';
-            }
-            fclose(hosts_fp);
-        }
-        free(etc_hosts_fn);
-    }
 
     aug = aug_init(root, loadpath, AUG_NO_STDINC | AUG_NO_LOAD);
 
@@ -65,31 +49,85 @@ static void readHostsFile() {
     aug_close(aug);
 }
 
-static void readHostsTree() {
+static void printHostsText() {
     struct augeas *aug;
     int r;
     char *s;
     char *etc_hosts_fn = NULL;
-    FILE *hosts_fp = NULL;
-    char *hosts_txt = NULL;
-    int readsz = 0;
 
     aug = aug_init(root, loadpath, AUG_NO_STDINC | AUG_NO_LOAD);
 
     r = aug_load_file(aug, "/etc/hosts");
     r = aug_preview(aug, "/files/etc/hosts/1", &s);
-
     std::cout << s << std::endl;
 
-    free(hosts_txt);
     free(s);
     aug_close(aug);
 }
 
 
+/// Get the tree of the /etc/hosts file printed in the console
+/// Implementation based on https://github.com/Nexenta/node-augeas/blob/756276c432cc9e506836800ac9d217bedbbef55c/libaugeas.cc#L784
+
+static void readHostsTree() {
+    struct augeas *aug;
+    int r;
+    FILE *out = tmpfile();
+    char *etc_hosts_fn = NULL;
+
+    aug = aug_init(root, loadpath, AUG_NO_STDINC | AUG_NO_LOAD);
+
+    const std::string matchPath = "/files/etc/hosts/*";
+
+    r = aug_load_file(aug, "/etc/hosts");
+    r = aug_print(aug, out,"/files/etc/hosts/*");
+
+    std::map <std::string, std::string> stdBindList;
+    std::map <std::string , std::string>::iterator pos;
+
+    char line[256];
+    rewind(out);
+    while (fgets(line, 256, out) != NULL) {
+        // remove end of line
+        line[strlen(line) - 1] = '\0';
+        std::string s = line;
+        ;
+        // skip comments
+        if (s.find("#comment") != std::string::npos)
+            continue;
+        s = s.substr(matchPath.length() - 1);
+        // split by '=' sign
+        size_t eqpos = s.find(" = ");
+        if (eqpos == std::string::npos)
+            continue;
+        // extract key and value
+        std::string key = s.substr(0, eqpos);
+        std::string value = s.substr(eqpos + 3);
+        // remove '"' sign from around value
+        value.erase(value.begin());
+        value.erase(value.end() - 1);
+        stdBindList.insert(std::pair<std::string,std::string>(key,value)); // 2
+
+    }
+
+
+    fclose(out);
+
+    for (pos = stdBindList.begin();pos!=stdBindList.end();pos++)
+    {
+        std::cout << "Key: " << pos->first << ";" << " Value: " << pos->second << std::endl;
+    }
+
+    aug_close(aug);
+
+
+
+}
+
+
 int main(int argc, char *argv[]) {
 
     testGet();
-    readHostsFile();
+    readHostsTree();
     return 0;
 }