# V语言 - 文件系统 [本站首页](/old/vref/) [中文文档](/old/vref/docs.html) [手册目录](/old/vref/menu/v.html) fn read_file(path string) string `read_file` reads the file in `path` and returns the contents. TODO return `?string` fn file_size(path string) int `file_size` returns the size of the file located in `path`. fn read_lines(path string) []string `read_lines` reads the file in `path` into an array of lines. fn open(path string) File fn create(path string) File `create` creates a file at a specified location and returns a writable `File` object. fn open_append(path string) File fn system2(cmd string) int `system2` starts the specified command, waits for it to complete, and returns its code. fn system(cmd string) string `system` starts the specified command, waits for it to complete, and returns its output. TODO merge the two functions. fn getenv(key string) string `getenv` returns the value of the environment variable named by the key. fn file_exists(path string) bool `file_exists` returns true if `path` exists. fn mkdir(path string) `mkdir` creates a new directory with the specified path. fn rm(path string) `rm` removes file in `path`. fn unzip(path, out string) fn basedir(path string) string fn filename(path string) string fn home_dir() string `home_dir` returns path to user's home directory