libc: Add support for pstat()

libs/libc/include/luna/pstat.h

@@ -0,0 +1,36 @@
+#ifndef _LUNA_PSTAT_H
+#define _LUNA_PSTAT_H
+
+#include <sys/types.h>
+
+struct pstat
+{
+    pid_t pt_pid;
+    pid_t pt_ppid;
+    char pt_name[128];
+    int pt_state;
+    pid_t pt_time;
+};
+
+#define PT_IDLE 0
+#define PT_RUNNING 1
+#define PT_SLEEPING 2
+#define PT_ZOMBIE 3
+#define PT_WAITING 4
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+    /* Returns information about the process with PID pid in buf, if buf is non-null. Luna-specific. */
+    pid_t pstat(pid_t pid, struct pstat* buf);
+
+    /* Returns a string representation of the process state in buf. */
+    const char* pstname(struct pstat* buf);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

libs/libc/include/sys/syscall.h

@@ -22,5 +22,6 @@
 #define SYS_waitpid 18
 #define SYS_access 19
 #define SYS_fstat 20
+#define SYS_pstat 21
 
 #endif

libs/libc/src/luna/pstat.cpp

@@ -0,0 +1,24 @@
+#include <luna/pstat.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+extern "C"
+{
+    pid_t pstat(pid_t pid, struct pstat* buf)
+    {
+        return syscall(SYS_pstat, pid, buf);
+    }
+
+    const char* pstname(struct pstat* buf)
+    {
+        switch (buf->pt_state)
+        {
+        case PT_IDLE: return "Idle";
+        case PT_RUNNING: return "Running";
+        case PT_SLEEPING: return "Sleeping";
+        case PT_WAITING: return "Waiting";
+        case PT_ZOMBIE: return "Zombie";
+        default: return "Unknown";
+        }
+    }
+}

libs/libc/src/syscall.cpp

@@ -24,6 +24,7 @@ extern "C" long syscall(long number, ...)
     case SYS_munmap:
     case SYS_access:
     case SYS_fstat:
+    case SYS_pstat:
     case SYS_open: {
         arg arg0 = va_arg(ap, arg);
         arg arg1 = va_arg(ap, arg);