Add sys$gethostname and /bin/hostname

Kernel/Syscall.cpp

@@ -100,6 +100,8 @@ DWORD handle(DWORD function, DWORD arg1, DWORD arg2, DWORD arg3)
         return (dword)current->sys$mmap((void*)arg1, (size_t)arg2);
     case Syscall::PosixMunmap:
         return current->sys$munmap((void*)arg1, (size_t)arg2);
+    case Syscall::PosixGethostname:
+        return current->sys$gethostname((char*)arg1, (size_t)arg2);
     case Syscall::PosixExit:
         cli();
         locker.unlock();

Kernel/Syscall.h

@@ -30,6 +30,7 @@ enum Function {
     PosixLstat = 0x1998,
     PosixGetcwd = 0x1999,
     PosixGettimeofday = 0x2000,
+    PosixGethostname = 0x2001,
 };
 
 void initialize();

Kernel/Task.cpp

@@ -24,6 +24,13 @@ Task* s_kernelTask;
 static pid_t next_pid;
 static InlineLinkedList<Task>* s_tasks;
 static InlineLinkedList<Task>* s_deadTasks;
+static String* s_hostname;
+
+static String& hostname(InterruptDisabler&)
+{
+    ASSERT(s_hostname);
+    return *s_hostname;
+}
 
 static bool contextSwitch(Task*);
 
@@ -61,6 +68,7 @@ void Task::initialize()
     s_tasks = new InlineLinkedList<Task>;
     s_deadTasks = new InlineLinkedList<Task>;
     s_kernelTask = Task::createKernelTask(nullptr, "colonel");
+    s_hostname = new String("birx");
     redoKernelTaskTSS();
     loadTaskRegister(s_kernelTask->selector());
 }
@@ -167,6 +175,18 @@ int Task::sys$munmap(void* addr, size_t size)
     return 0;
 }
 
+int Task::sys$gethostname(char* buffer, size_t size)
+{
+    String hn;
+    {
+        InterruptDisabler disabler;
+        hn = hostname(disabler).isolatedCopy();
+    }
+    if (size < (hn.length() + 1))
+        return -ENAMETOOLONG;
+    memcpy(buffer, hn.characters(), size);
+}
+
 int Task::sys$spawn(const char* path)
 {
     int error = 0;

Kernel/Task.h

@@ -100,6 +100,7 @@ public:
     int sys$getcwd(char*, size_t);
     int sys$sleep(unsigned seconds);
     int sys$gettimeofday(timeval*);
+    int sys$gethostname(char* name, size_t length);
 
     static void initialize();
 

Kernel/errno.h

@@ -34,5 +34,6 @@
 #define EPIPE     32    // Broken pipe
 #define EDOM      33    // Math argument out of domain of func
 #define ERANGE    34    // Math result not representable
+#define ENAMETOOLONG 36 // Name too long
 
-#define EOVERFLOW 75    // Value too large for defined data type 
+#define EOVERFLOW 75    // Value too large for defined data type

Kernel/sync-sh

@@ -9,5 +9,6 @@ cp ../Userland/sleep mnt/bin/sleep
 cp ../Userland/date mnt/bin/date
 cp ../Userland/true mnt/bin/true
 cp ../Userland/false mnt/bin/false
+cp ../Userland/hostname mnt/bin/hostname
 umount mnt
 sync