fix picture

.vscode/dryrun.log

@@ -2,6 +2,5 @@ make --dry-run --keep-going --print-directory
 make: Entering directory '/home/rand/xv6-rust'
 
 make -C kernel run
-
 make: Leaving directory '/home/rand/xv6-rust'
 

.vscode/targets.log

@@ -8,7 +8,7 @@ make: *** No rule to make target 'all'.  Stop.
 # This is free software: you are free to change and redistribute it.
 # There is NO WARRANTY, to the extent permitted by law.
 
-# Make data base, printed on Sat May 28 20:46:15 2022
+# Make data base, printed on Mon Jun  6 11:38:43 2022
 
 # Variables
 
@@ -131,7 +131,7 @@ XDG_SESSION_DESKTOP = ubuntu
 # environment
 SSH_AUTH_SOCK = /run/user/1000/keyring/ssh
 # environment
-GIO_LAUNCHED_DESKTOP_FILE_PID = 2601
+GIO_LAUNCHED_DESKTOP_FILE_PID = 71603
 # automatic
 %F = $(notdir $%)
 # environment
@@ -199,7 +199,7 @@ CC = riscv64-unknown-elf-gcc
 # environment
 GNOME_SHELL_SESSION_MODE = ubuntu
 # environment
-VSCODE_IPC_HOOK_EXTHOST = /run/user/1000/vscode-ipc-decc2bba-912c-42f1-9ef1-4bec104c8303.sock
+VSCODE_IPC_HOOK_EXTHOST = /run/user/1000/vscode-ipc-0ad2b37c-bce8-4ccf-8d31-e20adf2c6c74.sock
 # default
 MAKE_VERSION := 4.2.1
 # makefile (from 'Makefile', line 2)
@@ -228,7 +228,6 @@ MAKE_COMMAND := make
 LANGUAGE = zh_CN:zh
 # environment
 VSCODE_IPC_HOOK = /run/user/1000/vscode-f2998c1d-1.67.2-main.sock
-
 # environment
 BAMF_DESKTOP_FILE_HINT = /var/lib/snapd/desktop/applications/code_code.desktop
 # makefile
@@ -268,7 +267,7 @@ OBJCOPY = riscv64-unknown-elf-objcopy
 # default
 SUFFIXES := 
 # makefile (from 'Makefile', line 108)
-UPROGS = $(USER)/_init $(USER)/_sh $(USER)/_echo $(USER)/_ls $(USER)/_mkdir $(USER)/_touch $(USER)/_cat $(USER)/_rm $(USER)/_forktest $(USER)/_stressfs $(USER)/_sem_test1 $(USER)/_sem_test2 $(USER)/_thread_test $(USER)/_malloc_test $(USER)/_fork_test $(USER)/_fifo_test1 $(USER)/_fifo_test2 $(USER)/_pipe_test $(USER)/_uthreadtest $(USER)/_msgtest1 $(USER)/_msgtest2 $(USER)/_shmtest1 $(USER)/_shmtest2
+UPROGS = $(USER)/_init $(USER)/_sh $(USER)/_echo $(USER)/_ls $(USER)/_mkdir $(USER)/_touch $(USER)/_cat $(USER)/_rm $(USER)/_wc $(USER)/_forktest $(USER)/_stressfs $(USER)/_sem_test1 $(USER)/_sem_test2 $(USER)/_thread_test $(USER)/_malloc_test $(USER)/_fork_test $(USER)/_fifo_test1 $(USER)/_fifo_test2 $(USER)/_pipe_test $(USER)/_uthreadtest $(USER)/_msgtest1 $(USER)/_msgtest2 $(USER)/_shmtest1 $(USER)/_shmtest2 
 # environment
 SNAP_REEXEC = 
 # environment
@@ -279,23 +278,24 @@ WINDOWPATH = 2
 .INCLUDE_DIRS = /usr/include /usr/local/include /usr/include
 # environment
 GJS_DEBUG_OUTPUT = stderr
+
 # default
 .RECIPEPREFIX := 
 # environment
 LANG = C
 # environment
-VSCODE_PID = 2645
+VSCODE_PID = 71647
 # variable set hash-table stats:
-# Load=136/1024=13%, Rehash=0, Collisions=24/254=9%
+# Load=136/1024=13%, Rehash=0, Collisions=24/255=9%
 
 # Pattern-specific Variable Values
 
 # No pattern-specific variable values.
 
 # Directories
 
-# user (device 2053, inode 955528): 9 files, no impossibilities.
-# . (device 2053, inode 677081): 23 files, no impossibilities.
+# user (device 2053, inode 303738): 9 files, no impossibilities.
+# . (device 2053, inode 303342): 23 files, no impossibilities.
 
 # 32 files, no impossibilities in 2 directories.
 
@@ -317,6 +317,12 @@ xv6-user/_malloc_test:
 #  Modification time never checked.
 #  File has not been updated.
 
+# Not a target:
+xv6-user/_wc:
+#  Implicit rule search has not been done.
+#  Modification time never checked.
+#  File has not been updated.
+
 # Not a target:
 xv6-user/_shmtest2:
 #  Implicit rule search has not been done.
@@ -432,7 +438,7 @@ kernel/target/riscv64gc-unknown-none-elf/debug/kernel:
 # Not a target:
 Makefile:
 #  Implicit rule search has been done.
-#  Last modified 2022-05-28 20:45:43.935035161
+#  Last modified 2022-06-06 11:38:03.195113361
 #  File has been updated.
 #  Successfully updated.
 
@@ -504,12 +510,11 @@ xv6-user/uthread/setcontext.S:
 #  Modification time never checked.
 #  File has not been updated.
 
-fs.img: xv6-mkfs/mkfs README.md xv6-user/_init xv6-user/_sh xv6-user/_echo xv6-user/_ls xv6-user/_mkdir xv6-user/_touch xv6-user/_cat xv6-user/_rm xv6-user/_forktest xv6-user/_stressfs xv6-user/_sem_test1 xv6-user/_sem_test2 xv6-user/_thread_test xv6-user/_malloc_test xv6-user/_fork_test xv6-user/_fifo_test1 xv6-user/_fifo_test2 xv6-user/_pipe_test xv6-user/_uthreadtest xv6-user/_msgtest1 xv6-user/_msgtest2 xv6-user/_shmtest1 xv6-user/_shmtest2
+fs.img: xv6-mkfs/mkfs README.md xv6-user/_init xv6-user/_sh xv6-user/_echo xv6-user/_ls xv6-user/_mkdir xv6-user/_touch xv6-user/_cat xv6-user/_rm xv6-user/_wc xv6-user/_forktest xv6-user/_stressfs xv6-user/_sem_test1 xv6-user/_sem_test2 xv6-user/_thread_test xv6-user/_malloc_test xv6-user/_fork_test xv6-user/_fifo_test1 xv6-user/_fifo_test2 xv6-user/_pipe_test xv6-user/_uthreadtest xv6-user/_msgtest1 xv6-user/_msgtest2 xv6-user/_shmtest1 xv6-user/_shmtest2
 #  Implicit rule search has not been done.
-
 #  Modification time never checked.
 #  File has not been updated.
-#  recipe to execute (from 'Makefile', line 135):
+#  recipe to execute (from 'Makefile', line 136):
 	xv6-mkfs/mkfs fs.img README.md $(UPROGS)
 
 # Not a target:
@@ -554,6 +559,7 @@ xv6-user/_forktest: xv6-user/forktest.o xv6-user/ulib.o xv6-user/usys.o xv6-user
 #  File has not been updated.
 
 # Not a target:
+
 xv6-user/uthread/uthread.c:
 #  Implicit rule search has not been done.
 #  Modification time never checked.
@@ -709,19 +715,19 @@ xv6-mkfs/mkfs: xv6-mkfs/mkfs.c xv6-user/include/fs.h xv6-user/include/param.h
 	gcc -Werror -Wall -I./xv6-user -o xv6-mkfs/mkfs xv6-mkfs/mkfs.c
 
 # files hash-table stats:
-# Load=62/1024=6%, Rehash=0, Collisions=6/122=5%
+# Load=63/1024=6%, Rehash=0, Collisions=6/124=5%
 # VPATH Search Paths
 
 # No 'vpath' search paths.
 
 # No general ('VPATH' variable) search path.
 
-# strcache buffers: 1 (0) / strings = 90 / storage = 1345 B / avg = 14 B
-# current buf: size = 8162 B / used = 1345 B / count = 90 / avg = 14 B
+# strcache buffers: 1 (0) / strings = 91 / storage = 1358 B / avg = 14 B
+# current buf: size = 8162 B / used = 1358 B / count = 91 / avg = 14 B
 
-# strcache performance: lookups = 139 / hit rate = 35%
+# strcache performance: lookups = 140 / hit rate = 35%
 # hash-table stats:
-# Load=90/8192=1%, Rehash=0, Collisions=4/139=3%
-# Finished Make data base on Sat May 28 20:46:15 2022
+# Load=91/8192=1%, Rehash=0, Collisions=4/140=3%
+# Finished Make data base on Mon Jun  6 11:38:43 2022
 
 

Makefile

@@ -114,6 +114,7 @@ UPROGS=\
 	$(USER)/_touch \
 	$(USER)/_cat \
 	$(USER)/_rm \
+	$(USER)/_wc \
 	$(USER)/_forktest \
 	$(USER)/_stressfs \
 	$(USER)/_sem_test1 \
@@ -128,7 +129,7 @@ UPROGS=\
 	$(USER)/_msgtest1 \
 	$(USER)/_msgtest2 \
 	$(USER)/_shmtest1 \
-	$(USER)/_shmtest2
+	$(USER)/_shmtest2 
 
 
 fs.img: xv6-mkfs/mkfs README.md $(UPROGS)

README.md

@@ -1,168 +1,37 @@
-# xv6-rust
-## Introduction
+## 项目简介
 
-![](run.png)
+本项目是在去年比赛实现的 xv6-rust 基础之上进行二次开发，主要有两个方面：一是增加新的功能，二是修改完善现有代码的一些 bug，具体如下所示：
 
-This is a try to implement xv6 OS in pure Rust. 
+- 实现进程间的通信功能：
+  - 信号量
+  - 消息队列
+  - 共享内存
+  - 管道
 
-What's more, we are desired to add something new features into our OS, like network and GUI.  
+- 实现线程协程：
+  - 内核级线程
+  - 用户级线程(协程)
 
-The further goal of this project is to support multiple architecture and multiple boards, finally making our OS running in our own CPU.   
+- 简单封装运行库
+- 功能改进：
+  - 页面延迟分配
+  - 优先级调度
 
-For the purpose of supporting the feature of Rust language, I also intend to use `async/await` feature to implement kernel thread scheduler renewedly.  
+- 修改重构：
+  - 重写进程结构体及其锁的形式，改用大粒度锁
+  - 修改原有管道的 bug
+  - 修改内存管理的 bug
 
-Due to the complexity of the project and the busy course-work, I think it's hard to complete above work independently, so I'm sincerely hope others can interest on this project and join our teams.
+以上便是初赛阶段已完成的一些内容，还有一些目前正在做待完成
 
-## Start  
-### QEMU
-**Linux**:  
-```
-wget https://download.qemu.org/qemu-5.0.0.tar.x  
-tar xvJf qemu-5.0.0.tar.xz  
-cd qemu-5.0.0  
-./configure --target-list=riscv32-softmmu,riscv64-softmmu   
-make -j$(nproc)  
-sudo make install  
-```
-If you find some errors when building, you can slove by following hints:  
-- `ERROR: pkg-config binary 'pkg-config' not found` : `sudo apt-get install pkg-config`           
-- `ERROR: glib-2.48 gthread-2.0 is required to compile QEMU`: `sudo apt-get install libglib2.0-dev`       
-- `ERROR: pixman >= 0.21.8 not present`: `sudo apt-get install libpixman-1-dev` 
+- 模拟中断实现信号机制
+- 重新组织进程结构体，采用红黑树并实现 CFS 调度算法
+- 写时复制、mmap 等系统调用。
 
-### Rust
-You need download rust to start our environment. We suggest you to use official shell:  
-```
-curl https://sh.rustup.rs -sSf | sh
-```
-If you fail because of slow network speed. You can try this to speed up:   
-```
-export RUSTUP_DIST_SERVER=https://mirrors.ustc.edu.cn/rust-static
-export RUSTUP_UPDATE_ROOT=https://mirrors.ustc.edu.cn/rust-static/rustup
-curl https://sh.rustup.rs -sSf | sh
-```
+## 环境搭建
 
-If you have finished these, you can test your environment by following commands:  
-```
-source $HOME/.cargo/env  
-rustc --version
-```
-In addition,  we'd better change the package mirror address crates.io used by the package manager cargo to the mirror server of the University of Science and Technology of China to speed up the download of the tripartite library. We open (create a new file if it doesn't exist) ~/.cargo/config and modify the content to:  
-```
-[source.crates-io]
-registry = "https://github.com/rust-lang/crates.io-index"
-replace-with = 'ustc'
-[source.ustc]
-registry = "git://mirrors.ustc.edu.cn/crates.io-index"
-```
-Besides,  you also update some tools in rust:
+[环境搭建](docs/环境搭建.pdf)
 
-```
-rustup target add riscv64gc-unknown-none-elf
-cargo install cargo-binutils
-rustup component add llvm-tools-preview
-```
+## 设计文档
 
-Finally, you run this OS on your machine by excuteing following commands:  
-
-```
-git clone https://github.com/Ko-oK-OS/xv6-rust.git
-cd xv6-rust
-git submodule update --init --recursive
-make run
-```
-
-## GDB Usage
-To use gdb to debug, we need to download `riscv64-unkonown-elf-gdb` and `tmux`.
-
-### GDB Download
-- [Ubuntu](https://static.dev.sifive.com/dev-tools/riscv64-unknown-elf-gcc-8.3.0-2020.04.1-x86_64-linux-ubuntu14.tar.gz)
-- [CentOS](https://static.dev.sifive.com/dev-tools/riscv64-unknown-elf-gcc-8.3.0-2020.04.1-x86_64-linux-centos6.tar.gz)
-- [macOS](https://static.dev.sifive.com/dev-tools/riscv64-unknown-elf-gcc-8.3.0-2020.04.1-x86_64-apple-darwin.tar.gz)
-- [Windows](https://static.dev.sifive.com/dev-tools/riscv64-unknown-elf-gcc-8.3.0-2020.04.1-x86_64-w64-mingw32.zip)
-
-We support gdb in OS kernel, you can exectue this command in `xv6-rust/kernel` directory:   
-```shell
-make debug
-```
-And then you can debug this programe step by step. 
-
-## Schedule
-
-- Virtual Memory and Management   
-    - [x] Virtulal Memory Map
-    - [x] Kernel Allocator(Buddy System Allocator)  
-    - [x] Load ELF Files From Memory
-- Traps,Interrupts, and drivers
-    - [x] Kernel Trap
-    - [x] Users Trap
-    - [x] UART Drivers
-    - [x] Machine-Mode Timer Interrupt
-    - [x] Virtio Disk Drivers
-    - [x] PCI and E1000 Drivers
-- Locking
-    - [x] Spinlock
-    - [x] Sleeplock
-- Process and Scheduing
-    - [x] Process
-    - [x] Scheduing
-    - [x] Muti-Core Support
-    - [x] Syscall
-- File System
-    - [x] Mkfs
-    - [x] Buffer Layer
-    - [x] Log Layer
-    - [x] SuperBlock Layer
-    - [x] Inode Layer
-    - [x] Bitmap Layer
-    - [x] File Descriptor Layer
-    - [x] File Path
-    - [x] Pipe 
-    - [x] Syscall
-- NetWork
-    - [x] PCI and E1000 Initialize
-    - [x] Protocol Headers
-    - [ ] Network Card Driver
-    - [ ] Syscall
-- Device Driver
-    - [x] Virtio Disk
-    - [x] Uart/Console
-    - [x] PCI
-
-## Differences
-### Fs
-- [x] Remove `FILE_TABLE`
-- [x] Use `Arc` instead of `refs`, `Arc::clone()` will plat the same role of `refs++`
-- [ ] User `enum FileInner` to separate files of various file types
-
-### Scheduler
-- [ ] Use `VecDeque` instead of raw array.
-
-### Process
-- [ ] Use `BTreeMap` to maintain open files in `Process`
-- [ ] Add `Thread` in Kernel Process
-
-## Expected Future
-- [ ] More Clear Memory Model
-- [ ] Better Scheduler
-- [ ] SD Card Driver Support
-- [ ] Network Support(Use `smoltcp` to simplify design)
-- [ ] Async IO Support
-
-## Docs
-
-[项目设计文档](docs/项目设计文档.pdf)
-
-## References
-
-- [Building a stupid Mutex in the Rust](https://medium.com/@Mnwa/building-a-stupid-mutex-in-the-rust-d55886538889)  
-- [Rust源码分析：std::sync::Mutex](https://zhuanlan.zhihu.com/p/50006335)   
-- [buddy_system_allocator](https://github.com/rcore-os/buddy_system_allocator)  
-- [Write a OS in Rust](https://os.phil-opp.com)  
-- [rCore-Tutorial-v3](https://rcore-os.github.io/rCore-Tutorial-Book-v3/index.html)
-- [rCore-Tutorial](https://rcore-os.github.io/rCore-Tutorial-deploy/)  
-- [xv6-riscv](https://github.com/mit-pdos/xv6-riscv)
-- [xv6-riscv-rust](https://github.com/Jaic1/xv6-riscv-rust)
-- [rCore](https://github.com/rcore-os/rCore)
-
-## License
-MIT License
+[项目设计文档](docs/设计文档.pdf)

docs/环境搭建.md

@@ -0,0 +1,102 @@
+# 环境搭建
+
+## 1、ubuntu20.04 及相关环境
+
+```bash
+sudo apt-get update && sudo apt-get upgrade
+sudo apt-get install git build-essential gdb-multiarch qemu-system-misc gcc-riscv64-linux-gnu binutils-riscv64-linux-gnu
+sudo apt-get install riscv64-unknown-elf-gcc 
+#不能定位的话尝试 gcc-riscv64-unknown-elf
+```
+
+其他工具比如说 vim，vmtools 工具之类的
+
+## 2、qemu
+
+```bash
+wget https://download.qemu.org/qemu-5.0.0.tar.xz  
+tar xvJf qemu-5.0.0.tar.xz  
+cd qemu-5.0.0  
+./configure --target-list=riscv32-softmmu,riscv64-softmmu   
+make -j$(nproc)  
+sudo make install  
+```
+
+If you find some errors when building, you can slove by following hints:
+
+- `ERROR: pkg-config binary 'pkg-config' not found` : `sudo apt-get install pkg-config`
+- `ERROR: glib-2.48 gthread-2.0 is required to compile QEMU`: `sudo apt-get install libglib2.0-dev`
+- `ERROR: pixman >= 0.21.8 not present`: `sudo apt-get install libpixman-1-dev`
+
+## 3、clone
+
+```bash
+git clone https://github.com/Ko-oK-OS/xv6-rust.git
+```
+
+其中有三个子仓库 clone 不下来，自己克隆或者下载然后移动进去，因为权限的原因没法直接使用 
+
+```bash
+git submodule update --init --recursive
+```
+
+或者是去修改 .gitmodule 文件 URL 前缀为 https 
+
+![image-20220502221208991](C:/Users/Rand/AppData/Roaming/Typora/typora-user-images/image-20220502221208991.png)
+
+## 4、RUST相关环境
+
+You need download rust to start our environment. We suggest you to use official shell:
+
+```bash
+curl https://sh.rustup.rs -sSf | sh
+```
+
+If you fail because of slow network speed. You can try this to speed up:
+
+```bash
+export RUSTUP_DIST_SERVER=https://mirrors.ustc.edu.cn/rust-static
+export RUSTUP_UPDATE_ROOT=https://mirrors.ustc.edu.cn/rust-static/rustup
+curl https://sh.rustup.rs -sSf | sh
+```
+
+If you have finished these, you can test your environment by following commands:
+
+```bash
+source $HOME/.cargo/env  
+rustc --version
+```
+
+In addition, we'd better change the package mirror address crates.io used by the package manager cargo to the mirror server of the University of Science and Technology of China to speed up the download of the tripartite library. We open (create a new file if it doesn't exist) ~/.cargo/config and modify the content to:
+
+```
+[source.crates-io]
+registry = "https://github.com/rust-lang/crates.io-index"
+replace-with = 'ustc'
+[source.ustc]
+registry = "git://mirrors.ustc.edu.cn/crates.io-index"
+```
+
+Besides, you also update some tools in rust:
+
+```bash
+rustup target add riscv64gc-unknown-none-elf
+cargo install cargo-binutils
+rustup component add llvm-tools-preview
+```
+
+!!!!!!!!!!! 最后这一步的这两个命令
+
+```bash
+rustup target add riscv64gc-unknown-none-elf
+rustup component add llvm-tools-preview
+```
+
+需要在 xv6-rust 目录下执行一次，还需要在 xv6-rust/kernel 目录下执行一次
+
+## 5、搭建完成
+
+```
+make run
+```
+

kernel/src/fs/pipe.rs

@@ -56,6 +56,7 @@ impl Pipe {
         //     pipe: PipeData::alloc(),
         //     pipe_lock: Spinlock::new((), "pipe")
         // };
+
         let pipe = &mut *pipe_ptr;
         pipe.read_open = true;
         pipe.write_open = true;
@@ -113,6 +114,8 @@ impl Pipe {
         //     // pipe_guard.read_number += 1;
 
         // }
+
+
         let mut i = 0;
         while i < len {
             if self.nread == self.nwrite {
@@ -143,19 +146,13 @@ impl Pipe {
         let mut guard = self.pipe_lock.acquire();
         // let pipe = unsafe { &mut *self.pipe };
         let mut i = 0;
-
-        // pipe.write_open;
-
-        // println!("$$$");
-
-        // println!("@{} {}", pipe.write_number, pipe.read_number);
 
         while i < len {
             // println!("#{}", i);
-            // if !pipe.read_open || my_proc.killed() {
-            //     drop(guard);
-            //     return Err("pipe write: pipe read close or current process has been killed")
-            // }
+            if !self.read_open || my_proc.killed() {
+                drop(guard);
+                return Err("pipe write: pipe read close or current process has been killed")
+            }
             // println!("HEHE");
 
             if self.nwrite == self.nread + PIPE_SIZE {
@@ -167,15 +164,14 @@ impl Pipe {
                 my_proc.sleep(&self.nwrite as *const _ as usize, guard);
                 guard = self.pipe_lock.acquire();
             } else {
-                // println!("HAHA");
+
                 let mut char: u8 = 0;
                 let pgt = unsafe { &mut *my_proc.pagetable };
                 if pgt.copy_in(&mut char as *mut u8, addr + i, 1).is_err() {
                     break;
                 }
                 let write_cursor = self.nwrite % PIPE_SIZE;
                 self.data[write_cursor] = char;
-                // println!("+{}", char);
 
                 self.nwrite += 1;
                 i += 1;

kernel/src/ipc/bitmap.rs

@@ -10,12 +10,10 @@ use array_macro::array;
 pub const SHARE_MEM_AREA_SIZE: usize = 4*1024*1024;
 
 
-
 pub const SHARE_MEM_MAP_PAGES: usize = SHARE_MEM_AREA_SIZE/(PGSIZE);
 pub const SHARE_MEM_BIT_MAP_SIZE: usize = SHARE_MEM_MAP_PAGES/8+1;
 
 
-
 pub struct BitMap{
     bitmap: [u8; SHARE_MEM_BIT_MAP_SIZE]
 }

xv6-user/pipe_test.c

@@ -4,45 +4,32 @@
 
 int main(){
     int p[2];
-
     pipe(p);
     const char* str = "hello";
-
     printf("%x   %x\n", p[0], p[1]);
 
-
-
     if(fork() == 0){
-
-        printf("***** %d \n", (long)str);
-
+        // printf("***** %d \n", (long)str);
+
         close(1);
         dup(p[1]);
-
         close(p[0]);
         close(p[1]);
 
-
-
         write(1, str, 6);
 
-
-
-        printf("child exit\n");
-
         return 1;
     }else{
         wait(0);
 
         char buf[6];
         close(0);
         dup(p[0]);
-
-
+
         close(p[0]);
         close(p[1]);
 
-        read(0, buf, 6);
+        read(0, buf, 12);
 
         printf("$$$$$ %s \n", buf);
 

xv6-user/wc.c

@@ -0,0 +1,55 @@
+#include "include/types.h"
+#include "include/stat.h"
+#include "include/param.h"
+#include "user.h"
+
+char buf[512];
+
+void
+wc(int fd, char *name)
+{
+  int i, n;
+  int l, w, c, inword;
+
+  l = w = c = 0;
+  inword = 0;
+  while((n = read(fd, buf, sizeof(buf))) > 0){
+    for(i=0; i<n; i++){
+      c++;
+      if(buf[i] == '\n')
+        l++;
+      if(strchr(" \r\t\n\v", buf[i]))
+        inword = 0;
+      else if(!inword){
+        w++;
+        inword = 1;
+      }
+    }
+  }
+  if(n < 0){
+    printf("wc: read error\n");
+    exit(1);
+  }
+  printf("%d %d %d %s\n", l, w, c, name);
+}
+
+int
+main(int argc, char *argv[])
+{
+  int fd, i;
+
+  if(argc <= 1){
+    wc(0, "");
+    exit(0);
+  }
+
+  for(i = 1; i < argc; i++){
+    if((fd = open(argv[i], 0)) < 0){
+      printf("wc: cannot open %s\n", argv[i]);
+      exit(1);
+    }
+    wc(fd, argv[i]);
+    close(fd);
+  }
+  exit(0);
+}