4 files changed, 125 insertions, 6 deletions

diff --git a/src/blocks/group.c b/src/blocks/group.c
index fb4457e..4fcb420 100644
--- a/src/blocks/group.c
+++ b/src/blocks/group.c
@@ -7,6 +7,6 @@ const block_scheme_t block_group_scheme = {
     },
     .size = 0,
     .entries = NULL,
-    .verify = NULL,
+    .validate = NULL,
 };
 
diff --git a/src/blocks/ram.c b/src/blocks/ram.c
index a626413..44dd1a3 100644
--- a/src/blocks/ram.c
+++ b/src/blocks/ram.c
@@ -1,12 +1,118 @@
+#include <string.h>
+#include <stdio.h>
+#include <assert.h>
+#include <stdlib.h>
+
 #include "scheme.h"
 
+#include "../any_log.h"
+
+char *str_replace(char *orig, char *rep, char *with) {
+    char *result; // the return string
+    char *ins;    // the next insert point
+    char *tmp;    // varies
+    int len_rep;  // length of rep (the string to remove)
+    int len_with; // length of with (the string to replace rep with)
+    int len_front; // distance between rep and end of last rep
+    int count;    // number of replacements
+
+    // sanity checks and initialization
+    if (!orig || !rep)
+        return NULL;
+    len_rep = strlen(rep);
+    if (len_rep == 0)
+        return NULL; // empty rep causes infinite loop during count
+    if (!with)
+        with = "";
+    len_with = strlen(with);
+
+    // count the number of replacements needed
+    ins = orig;
+    for (count = 0; (tmp = strstr(ins, rep)); ++count) {
+        ins = tmp + len_rep;
+    }
+
+    tmp = result = malloc(strlen(orig) + (len_with - len_rep) * count + 1);
+
+    if (!result)
+        return NULL;
+
+    // first time through the loop, all the variable are set correctly
+    // from here on,
+    //    tmp points to the end of the result string
+    //    ins points to the next occurrence of rep in orig
+    //    orig points to the remainder of orig after "end of rep"
+    while (count--) {
+        ins = strstr(orig, rep);
+        len_front = ins - orig;
+        tmp = strncpy(tmp, orig, len_front) + len_front;
+        tmp = strcpy(tmp, with) + len_with;
+        orig += len_front + len_rep; // move to next "end of rep"
+    }
+    strcpy(tmp, orig);
+    return result;
+}
+
+static void block_ram_update(block_t *block)
+{
+    FILE *meminfo = fopen("/proc/meminfo", "rb");
+    assert(meminfo != NULL);
+
+    uintmax_t total, unused, buffers, cached;
+    assert(5 == fscanf(meminfo,
+                       "MemTotal: %ju kB\n"
+                       "MemFree: %ju kB\n"
+                       "MemAvailable: %ju kB\n"
+                       "Buffers: %ju kB\n"
+                       "Cached: %ju kB\n",
+                       &total, &unused, &buffers, &buffers, &cached));
+
+    int usage = 100 * (total - unused - buffers - cached) / total;
+    fclose(meminfo);
+
+    free(block->text.text);
+
+    char str[100];
+    sprintf(str, "%d", usage);
+
+    block->text.text = str_replace(block->state, "%{ram}", str);
+    assert(block->text.text != NULL);
+}
+
+static void block_ram_finalize(block_t *block)
+{
+    free(block->state);
+}
+
+static bool block_ram_validate(block_t *block, const block_scheme_t *scheme)
+{
+    block->state = block->text.text;
+    block->text.text = NULL;
+
+    if (block->state == NULL) {
+        log_error("Block '%s' requires key '%s'", block->label, "text");
+        return false;
+    }
+
+    if (strstr(block->state, "%{ram}") != NULL)
+        log_warn("Block '%s' does not have a ram format", block->label);
+
+    return true;
+}
+
 const block_scheme_t block_ram_scheme = {
     .name = "ram",
     .block = {
         .type = BLOCK_TEXT,
+        .update_interval = {
+            .tv_sec = 1,
+            .tv_nsec = 0,
+        },
+        .update_cb = block_ram_update,
+        .finalize_cb = block_ram_finalize,
     },
-    .size = 0,
+    .size = sizeof(char *),
     .entries = NULL,
-    .verify = NULL,
+    .validate = block_ram_validate,
 };
 
diff --git a/src/blocks/scheme.h b/src/blocks/scheme.h
index 2bcca97..1795013 100644
--- a/src/blocks/scheme.h
+++ b/src/blocks/scheme.h
@@ -5,14 +5,15 @@
 
 typedef struct block_scheme block_scheme_t;
 
-typedef bool (*block_scheme_verify_t)(block_t *block, block_scheme_t *scheme);
+typedef bool (*block_validate_t)(block_t *block, const block_scheme_t *scheme);
 
 struct block_scheme {
     const char *name;
     block_t block;
     size_t size;
     const config_entry_t *entries;
-    block_scheme_verify_t verify;
+    block_validate_t validate;
+    //block_resolve_t resolve;
 };
 
 extern const block_scheme_t *block_schemes[];
diff --git a/src/blocks/text.c b/src/blocks/text.c
index 0e5fc31..f2c1651 100644
--- a/src/blocks/text.c
+++ b/src/blocks/text.c
@@ -1,5 +1,17 @@
 #include "scheme.h"
 
+#include "../any_log.h"
+
+static bool block_text_validate(block_t *block, const block_scheme_t *scheme)
+{
+    if (block->text.text == NULL) {
+        log_error("Block '%s' requires key '%s'", block->label, "text");
+        return false;
+    }
+
+    return true;
+}
+
 const block_scheme_t block_text_scheme = {
     .name = "text",
     .block = {
@@ -7,5 +19,5 @@ const block_scheme_t block_text_scheme = {
     },
     .size = 0,
     .entries = NULL,
-    .verify = NULL,
+    .validate = block_text_validate,
 };