diff --git a/components/libc/compilers/armlibc/sys/unistd.h b/components/libc/compilers/armlibc/sys/unistd.h
index e1a1ad92f4..ee1e1c4db9 100644
--- a/components/libc/compilers/armlibc/sys/unistd.h
+++ b/components/libc/compilers/armlibc/sys/unistd.h
@@ -73,7 +73,11 @@ char *  ttyname     (int desc);
 unsigned int sleep(unsigned int seconds);
 int usleep(useconds_t usec);
 
-uid_t getuid(void);
 pid_t getpid(void);
+pid_t getppid(void);
+uid_t getuid(void);
+uid_t geteuid(void);
+gid_t getgid(void);
+gid_t getegid(void);
 
 #endif /* _SYS_UNISTD_H */
diff --git a/components/libc/compilers/common/unistd.c b/components/libc/compilers/common/unistd.c
index c7ad654da7..b3efc386e9 100644
--- a/components/libc/compilers/common/unistd.c
+++ b/components/libc/compilers/common/unistd.c
@@ -50,14 +50,38 @@ int usleep(useconds_t usec)
 }
 RTM_EXPORT(usleep);
 
+pid_t getpid(void)
+{
+    return 0;
+}
+RTM_EXPORT(getpid);
+
+pid_t getppid(void)
+{
+    return 0;
+}
+RTM_EXPORT(getppid);
+
 uid_t getuid(void)
 {
-    return -1;
+    return 0;
 }
 RTM_EXPORT(getuid);
 
-pid_t getpid(void)
+uid_t geteuid(void)
 {
-    return -1;
+    return 0;
 }
-RTM_EXPORT(getuid);
+RTM_EXPORT(geteuid);
+
+gid_t getgid(void)
+{
+    return 0;
+}
+RTM_EXPORT(getgid);
+
+gid_t getegid(void)
+{
+    return 0;
+}
+RTM_EXPORT(getegid);
diff --git a/components/libc/compilers/dlib/sys/unistd.h b/components/libc/compilers/dlib/sys/unistd.h
index 5ca56ad136..5b86822635 100644
--- a/components/libc/compilers/dlib/sys/unistd.h
+++ b/components/libc/compilers/dlib/sys/unistd.h
@@ -47,7 +47,11 @@ char *  ttyname     (int desc);
 unsigned int sleep(unsigned int seconds);
 int usleep(useconds_t usec);
 
-uid_t getuid(void);
 pid_t getpid(void);
+pid_t getppid(void);
+uid_t getuid(void);
+uid_t geteuid(void);
+gid_t getgid(void);
+gid_t getegid(void);
 
 #endif /* _SYS_UNISTD_H */