libc: Add dummy getcwd()

kernel/include/std/errno.h

@@ -16,5 +16,6 @@
 #define EMFILE 24
 #define ENOTTY 25
 #define ENOSPC 28
+#define ERANGE 36
 #define ENOSYS 38
 #define ENOTSUP 95

libs/libc/include/errno.h

@@ -21,6 +21,7 @@ extern int errno;
 #define ENOTTY 25  // Inappropriate ioctl for device
 #define ENOSPC 28  // No space left on device
 #define EPIPE 32   // Broken pipe. Not implemented.
+#define ERANGE 34  // Numerical result out of range
 #define ENOSYS 38  // Function not implemented
 #define ENOTSUP 95 // Operation not supported
 

libs/libc/include/unistd.h

@@ -69,6 +69,9 @@ extern "C"
     /* Checks if the file descriptor fd refers to a terminal. */
     int isatty(int fd);
 
+    /* Writes the current process's current working directory to buf. */
+    char* getcwd(char* buf, size_t size);
+
 #ifdef __cplusplus
 }
 #endif

libs/libc/src/string.cpp

@@ -274,6 +274,7 @@ extern "C"
         case ENOTTY: return "Inappropriate ioctl for device";
         case ENOSPC: return "No space left on device";
         case EPIPE: return "Broken pipe";
+        case ERANGE: return "Numerical result out of range";
         case ENOSYS: return "Function not implemented";
         case ENOTSUP: return "Operation not supported";
         case 0: return "Success";

libs/libc/src/unistd.cpp

@@ -1,5 +1,8 @@
+#include <errno.h>
 #include <fcntl.h>
 #include <luna.h>
+#include <stdlib.h>
+#include <string.h>
 #include <sys/syscall.h>
 #include <unistd.h>
 
@@ -81,4 +84,16 @@ extern "C"
         if (result < 0) return 0;
         return 1;
     }
+
+    char* getcwd(char* buf, size_t size)
+    {
+        const char* dummy_cwd = "/"; // FIXME: Actually retrieve the current working directory from the kernel.
+        if (size < 2)
+        {
+            errno = ERANGE;
+            return NULL;
+        }
+        if (!buf) { buf = (char*)malloc(size); }
+        strlcpy(buf, dummy_cwd, 2);
+    }
 }