1 use alloc::{string::String, sync::Arc}; 2 3 use crate::{process::ProcessControlBlock, syscall::SystemError}; 4 5 use super::{fcntl::AtFlags, FileType, IndexNode, ROOT_INODE}; 6 7 /// @brief 切分路径字符串，返回最左侧那一级的目录名和剩余的部分。 8 /// 9 /// 举例：对于 /123/456/789/ 本函数返回的第一个值为123, 第二个值为456/789 10 #[allow(dead_code)] 11 pub fn split_path(path: &str) -> (&str, Option<&str>) { 12 let mut path_split: core::str::SplitN<&str> = path.trim_matches('/').splitn(2, "/"); 13 let comp = path_split.next().unwrap_or(""); 14 let rest_opt = path_split.next(); 15 16 return (comp, rest_opt); 17 } 18 19 /// @brief 切分路径字符串，返回最右侧那一级的目录名和剩余的部分。 20 /// 21 /// 举例：对于 /123/456/789/ 本函数返回的第一个值为789, 第二个值为123/456 22 pub fn rsplit_path(path: &str) -> (&str, Option<&str>) { 23 let mut path_split: core::str::RSplitN<&str> = path.trim_matches('/').rsplitn(2, "/"); 24 let comp = path_split.next().unwrap_or(""); 25 let rest_opt = path_split.next(); 26 27 return (comp, rest_opt); 28 } 29 30 /// 根据dirfd和path，计算接下来开始lookup的inode和剩余的path 31 /// 32 /// ## 返回值 33 /// 34 /// 返回值为(需要执行lookup的inode, 剩余的path) 35 pub fn user_path_at( 36 pcb: &Arc<ProcessControlBlock>, 37 dirfd: i32, 38 path: &str, 39 ) -> Result<(Arc<dyn IndexNode>, String), SystemError> { 40 let mut inode = ROOT_INODE(); 41 let ret_path; 42 // 如果path不是绝对路径，则需要拼接 43 if path.as_bytes()[0] != b'/' { 44 // 如果dirfd不是AT_FDCWD，则需要检查dirfd是否是目录 45 if dirfd != AtFlags::AT_FDCWD.bits() { 46 let binding = pcb.fd_table(); 47 let fd_table_guard = binding.read(); 48 let file = fd_table_guard 49 .get_file_by_fd(dirfd) 50 .ok_or(SystemError::EBADF)?; 51 52 // drop guard 以避免无法调度的问题 53 drop(fd_table_guard); 54 55 let file_guard = file.lock(); 56 // 如果dirfd不是目录，则返回错误码ENOTDIR 57 if file_guard.file_type() != FileType::Dir { 58 return Err(SystemError::ENOTDIR); 59 } 60 61 inode = file_guard.inode(); 62 ret_path = String::from(path); 63 } else { 64 let mut cwd = pcb.basic().cwd(); 65 cwd.push('/'); 66 cwd.push_str(path); 67 ret_path = cwd; 68 } 69 } else { 70 ret_path = String::from(path); 71 } 72 73 return Ok((inode, ret_path)); 74 } 75