add realpath() function

src/libcglue/Makefile.am

@@ -29,7 +29,8 @@ GLUE_OBJS = __dummy_passwd.o __psp_heap_blockid.o __psp_free_heap.o _fork.o _wai
 	_rename.o _getpid.o _kill.o _sbrk.o _gettimeofday.o _times.o ftime.o clock_getres.o clock_gettime.o clock_settime.o \
 	_isatty.o symlink.o truncate.o chmod.o fchmod.o pathconf.o readlink.o utime.o fchown.o _getentropy.o getpwuid.o \
 	fsync.o getpwnam.o getuid.o geteuid.o basename.o statvfs.o \
-	openat.o renameat.o fchmodat.o fstatat.o mkdirat.o faccessat.o fchownat.o linkat.o readlinkat.o unlinkat.o
+	openat.o renameat.o fchmodat.o fstatat.o mkdirat.o faccessat.o fchownat.o linkat.o readlinkat.o unlinkat.o \
+	realpath.o
 
 INIT_OBJS = __libpthreadglue_init.o __libcglue_init.o __libcglue_deinit.o _exit.o abort.o exit.o
 

src/libcglue/glue.c

@@ -1179,3 +1179,38 @@ int unlinkat(int dirfd, const char *pathname, int flags)
 	}
 }
 #endif /* F_unlinkat  */
+
+#ifdef F_realpath
+char *realpath(const char *path, char *resolved_path)
+{
+	if (path == NULL) {
+		errno = EINVAL;
+		return NULL;
+	}
+
+	if (strlen(path) > PATH_MAX) {
+		errno = ENAMETOOLONG;
+		return NULL;
+	}
+
+	/* check if file or directory exist */
+	struct stat st;
+	if (stat(path, &st) < 0) {
+		errno = ENOENT;
+		return NULL;
+	}
+
+	// if resolved_path arg is NULL, use malloc instead
+	if (resolved_path == NULL) {
+		resolved_path = (char *)malloc(PATH_MAX * sizeof(char));
+		if (resolved_path == NULL) {
+			errno = ENOMEM;
+			return NULL;
+		}
+	}
+
+	__path_absolute(path, resolved_path, PATH_MAX);
+
+	return resolved_path;
+}
+#endif /* F_realpath */