Kernel+Userland: Convert /proc/df to JSON.

Kernel/FileSystem/ProcFS.cpp

@@ -450,18 +450,19 @@ ByteBuffer procfs$mounts(InodeIdentifier)
 ByteBuffer procfs$df(InodeIdentifier)
 {
     // FIXME: This is obviously racy against the VFS mounts changing.
-    StringBuilder builder;
-    VFS::the().for_each_mount([&builder](auto& mount) {
+    JsonArray json;
+    VFS::the().for_each_mount([&json](auto& mount) {
         auto& fs = mount.guest_fs();
-        builder.appendf("%s,", fs.class_name());
-        builder.appendf("%u,", fs.total_block_count());
-        builder.appendf("%u,", fs.free_block_count());
-        builder.appendf("%u,", fs.total_inode_count());
-        builder.appendf("%u,", fs.free_inode_count());
-        builder.append(mount.absolute_path());
-        builder.append('\n');
+        JsonObject fs_object;
+        fs_object.set("class_name", fs.class_name());
+        fs_object.set("total_block_count", fs.total_block_count());
+        fs_object.set("free_block_count", fs.free_block_count());
+        fs_object.set("total_inode_count", fs.total_inode_count());
+        fs_object.set("free_inode_count", fs.free_inode_count());
+        fs_object.set("mount_point", mount.absolute_path());
+        json.append(fs_object);
     });
-    return builder.to_byte_buffer();
+    return json.serialized().to_byte_buffer();
 }
 
 ByteBuffer procfs$cpuinfo(InodeIdentifier)

Userland/df.cpp

@@ -1,5 +1,8 @@
 #include <AK/AKString.h>
+#include <AK/JsonArray.h>
+#include <AK/JsonObject.h>
 #include <AK/Vector.h>
+#include <LibCore/CFile.h>
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -16,31 +19,23 @@ struct FileSystem {
 
 int main(int, char**)
 {
-    FILE* fp = fopen("/proc/df", "r");
-    if (!fp) {
-        perror("failed to open /proc/df");
+    CFile file("/proc/df");
+    if (!file.open(CIODevice::ReadOnly)) {
+        fprintf(stderr, "Failed to open /proc/df: %s\n", file.error_string());
         return 1;
     }
     printf("Filesystem    Blocks        Used    Available   Mount point\n");
-    for (;;) {
-        char buf[4096];
-        char* ptr = fgets(buf, sizeof(buf), fp);
-        if (!ptr)
-            break;
-        auto parts = String(buf, Chomp).split(',');
-        if (parts.size() < 6)
-            break;
-        bool ok;
-        String fs = parts[0];
-        unsigned total_block_count = parts[1].to_uint(ok);
-        ASSERT(ok);
-        unsigned free_block_count = parts[2].to_uint(ok);
-        ASSERT(ok);
-        unsigned total_inode_count = parts[3].to_uint(ok);
-        ASSERT(ok);
-        unsigned free_inode_count = parts[4].to_uint(ok);
-        ASSERT(ok);
-        String mount_point = parts[5];
+
+    auto file_contents = file.read_all();
+    auto json = JsonValue::from_string(file_contents).as_array();
+    json.for_each([](auto& value) {
+        auto fs_object = value.as_object();
+        auto fs = fs_object.get("class_name").to_string();
+        auto total_block_count = fs_object.get("total_block_count").to_dword();
+        auto free_block_count = fs_object.get("free_block_count").to_dword();
+        auto total_inode_count = fs_object.get("total_inode_count").to_dword();
+        auto free_inode_count = fs_object.get("free_inode_count").to_dword();
+        auto mount_point = fs_object.get("mount_point").to_string();
 
         (void)total_inode_count;
         (void)free_inode_count;
@@ -51,8 +46,7 @@ int main(int, char**)
         printf("%10u   ", free_block_count);
         printf("%s", mount_point.characters());
         printf("\n");
-    }
-    int rc = fclose(fp);
-    ASSERT(rc == 0);
+    });
+
     return 0;
 }