dev(shell): implement basic shell tools

fixed(file-system): fixed read and write bugs

13 files changed, 421 insertions, 20 deletions

diff --git a/src/fs/fat32.cc b/src/fs/fat32.cc
index 5c70f5a..17b543c 100644
--- a/src/fs/fat32.cc
+++ b/src/fs/fat32.cc
@@ -141,8 +141,6 @@ uint32 FAT32FileSystem::next_cluster(uint32 cluster)
     uint32 ent_offset = fat_offset % 512;
 
     // block = sector / 2
-    // offset in block = (sector % 2) * 512 + ent_offset
-
     struct Buf *b = BufferCache::bread(0, fat_sector / 2);
 
     uint32 block_offset = (fat_sector % 2) * 512 + ent_offset;
@@ -177,6 +175,20 @@ int FAT32Inode::read(char *dst, uint32 off, uint32 n, int isUser)
     if (first_clus == 0)
         return 0;
 
+    // [FIX] 只有非目录文件才检查 size 边界
+    // 目录文件 size 可能为 0，应允许读取直到簇链结束
+    if (type != T_DIR)
+    {
+        if (off >= size)
+        {
+            return 0;
+        }
+        if (off + n > size)
+        {
+            n = size - off;
+        }
+    }
+
     uint32 tot = 0;
     uint32 clus = first_clus;
     uint32 clus_sz = fs->bytes_per_cluster;
@@ -303,7 +315,7 @@ uint32 FAT32FileSystem::alloc_cluster()
         uint32 current_fat_sec = fat_start_sector + i;
         struct Buf *b = BufferCache::bread(0, current_fat_sec / 2);
         uint32 *table = (uint32 *)(b->data + (current_fat_sec % 2) * 512);
-        for(uint32 j = 0; j <  fat_entries_per_sector; j++)
+        for (uint32 j = 0; j < fat_entries_per_sector; j++)
         {
             if (i == 0 && j < 2)
                 continue;
@@ -359,7 +371,6 @@ void FAT32FileSystem::free_cluster_chain(uint32 cluster)
 
         cluster = next;
     }
-    
 }
 
 void FAT32Inode::update()
@@ -654,7 +665,9 @@ int FAT32Inode::unlink(const char *name)
 
     uint32_t clus = first_clus;
     bool found = false;
-    struct Buf *target_buf = nullptr;
+
+    // [FIX] Deadlock prevention: Do not hold buffer while looking up inode
+    uint32_t target_block = 0;
     uint32_t target_offset = 0;
     struct FAT32_DirEnt de;
 
@@ -681,16 +694,16 @@ int FAT32Inode::unlink(const char *name)
 
                 if (match_name(de.name, name))
                 {
-                    target_buf = b;
+                    target_block = (sec + i) / 2;
                     target_offset = ((sec + i) % 2) * 512 + off;
                     found = true;
                     break;
                 }
             }
 
+            BufferCache::brelse(b); // Always release buffer
             if (found)
                 break;
-            BufferCache::brelse(b);
         }
 
         if (found)
@@ -701,7 +714,7 @@ int FAT32Inode::unlink(const char *name)
             return -1;
     }
 
-    if (found && target_buf)
+    if (found)
     {
         Inode *target_ip = lookup(name);
         if (target_ip)
@@ -710,7 +723,6 @@ int FAT32Inode::unlink(const char *name)
             if (target_ip->type == T_DIR)
             {
                 VFS::iunlockput(target_ip);
-                BufferCache::brelse(target_buf);
                 return -1;
             }
 
@@ -719,6 +731,8 @@ int FAT32Inode::unlink(const char *name)
             VFS::iunlockput(target_ip);
         }
 
+        // Re-read buffer to mark deletion
+        struct Buf *target_buf = BufferCache::bread(dev, target_block);
         uint8_t *ptr = (uint8_t *)target_buf->data + target_offset;
         *ptr = 0xE5;
 
diff --git a/src/fs/file.cc b/src/fs/file.cc
index 623b535..9f12dc1 100644
--- a/src/fs/file.cc
+++ b/src/fs/file.cc
@@ -217,6 +217,16 @@ namespace FileTable
         if (f->type == FD_INODE)
         {
             VFS::ilock(f->ip);
+
+            if (f->ip->type == T_DEVICE)
+            {
+                if (f->ip->major == 1)
+                {
+                    VFS::iunlock(f->ip);
+                    return Drivers::console_read(addr, n);
+                }
+            }
+
             int r = f->ip->read((char*)addr, f->off, n, 1);
             if(r > 0)
             {
@@ -240,6 +250,37 @@ namespace FileTable
         if (f->type == FD_INODE)
         {
             VFS::ilock(f->ip);
+
+            if (f->ip->type == T_DEVICE)
+            {
+                if (f->ip->major == 1) // Console
+                {
+                    VFS::iunlock(f->ip);
+                    struct Proc *proc = myproc();
+                    constexpr int MAX_WRITE_BUF = 128;
+                    char buf[MAX_WRITE_BUF];
+                    int i = 0;
+                    while (i < n)
+                    {
+                        int len = n - i;
+                        if (len > MAX_WRITE_BUF)
+                            len = MAX_WRITE_BUF;
+
+                        if (VM::copyin(proc->pagetable, buf, addr + i, static_cast<uint64>(len)) < 0)
+                        {
+                            return -1;
+                        }
+
+                        for (int j = 0; j < len; j++)
+                        {
+                            Drivers::uart_putc(buf[j]);
+                        }
+                        i += len;
+                    }
+                    return n;
+                }
+            }
+
             int r = f->ip->write((char *)addr, f->off, n, 1);
             if (r > 0)
             {
diff --git a/src/kernel/syscall.cc b/src/kernel/syscall.cc
index 259a5e6..9f88649 100644
--- a/src/kernel/syscall.cc
+++ b/src/kernel/syscall.cc
@@ -503,7 +503,9 @@ static uint64_t sys_read()
     // get param: fd, buf, len
     if (argint(0, &fd) < 0 || argint(2, &n) < 0 || argint(1, (int *)&p) < 0)
         return -1;
-    
+        
+    p = argraw(1);
+
     struct Proc* proc = myproc();
     if (fd == 0 && proc->ofile[fd] == nullptr)
     {
diff --git a/src/user/cat.cc b/src/user/cat.cc
new file mode 100644
index 0000000..67feb1c
--- /dev/null
+++ b/src/user/cat.cc
@@ -0,0 +1,48 @@
+#include "ulib/stdio.h"
+#include "ulib/stdlib.h"
+#include "ulib/string.h"
+#include "user/user.h"
+#include "common/fcntl.h"
+
+char buf[512];
+
+void cat(int fd)
+{
+    int n;
+    while ((n = read(fd, buf, sizeof(buf))) > 0)
+    {
+        if (write(1, buf, n) != n)
+        {
+            printf("cat: write error\n");
+            exit(1);
+        }
+    }
+    if (n < 0)
+    {
+        printf("cat: read error\n");
+        exit(1);
+    }
+}
+
+int main(int argc, char *argv[])
+{
+    int fd, i;
+
+    if (argc <= 1)
+    {
+        cat(0);
+        exit(0);
+    }
+
+    for (i = 1; i < argc; i++)
+    {
+        if ((fd = open(argv[i], O_RDONLY)) < 0)
+        {
+            printf("cat: cannot open %s\n", argv[i]);
+            exit(1);
+        }
+        cat(fd);
+        close(fd);
+    }
+    exit(0);
+}
\ No newline at end of file
diff --git a/src/user/cp.cc b/src/user/cp.cc
new file mode 100644
index 0000000..9f13bef
--- /dev/null
+++ b/src/user/cp.cc
@@ -0,0 +1,48 @@
+#include "ulib/stdio.h"
+#include "ulib/stdlib.h"
+#include "user/user.h"
+#include "common/fcntl.h"
+
+char buf[512];
+
+int main(int argc, char *argv[])
+{
+    int fd_src, fd_dst, n;
+
+    if (argc != 3)
+    {
+        printf("Usage: cp src dst\n");
+        exit(1);
+    }
+
+    if ((fd_src = open(argv[1], O_RDONLY)) < 0)
+    {
+        printf("cp: cannot open source %s\n", argv[1]);
+        exit(1);
+    }
+
+    if ((fd_dst = open(argv[2], O_WRONLY | O_CREATE | O_TRUNC)) < 0)
+    {
+        printf("cp: cannot create destination %s\n", argv[2]);
+        close(fd_src);
+        exit(1);
+    }
+
+    while ((n = read(fd_src, buf, sizeof(buf))) > 0)
+    {
+        if (write(fd_dst, buf, n) != n)
+        {
+            printf("cp: write error\n");
+            exit(1);
+        }
+    }
+
+    if (n < 0)
+    {
+        printf("cp: read error\n");
+    }
+
+    close(fd_src);
+    close(fd_dst);
+    exit(0);
+}
\ No newline at end of file
diff --git a/src/user/grep.cc b/src/user/grep.cc
new file mode 100644
index 0000000..5ed61b4
--- /dev/null
+++ b/src/user/grep.cc
@@ -0,0 +1,68 @@
+#include "ulib/stdio.h"
+#include "ulib/stdlib.h"
+#include "ulib/string.h"
+#include "user/user.h"
+#include "common/fcntl.h"
+
+char buf[1024];
+
+void grep(char *pattern, int fd)
+{
+    int n, m;
+    char *p, *q;
+
+    m = 0;
+    while ((n = read(fd, buf + m, sizeof(buf) - m - 1)) > 0)
+    {
+        m += n;
+        buf[m] = '\0';
+        p = buf;
+        while ((q = strchr(p, '\n')) != 0)
+        {
+            *q = 0;
+            if (strstr(p, pattern) != 0)
+            {
+                printf("%s\n", p);
+            }
+            p = q + 1;
+        }
+        if (p == buf)
+            m = 0;
+        if (m > 0)
+        {
+            m -= p - buf;
+            memmove(buf, p, m);
+        }
+    }
+}
+
+int main(int argc, char *argv[])
+{
+    int fd, i;
+    char *pattern;
+
+    if (argc < 2)
+    {
+        printf("Usage: grep pattern [file...]\n");
+        exit(1);
+    }
+    pattern = argv[1];
+
+    if (argc == 2)
+    {
+        grep(pattern, 0); // stdin
+        exit(0);
+    }
+
+    for (i = 2; i < argc; i++)
+    {
+        if ((fd = open(argv[i], O_RDONLY)) < 0)
+        {
+            printf("grep: cannot open %s\n", argv[i]);
+            exit(1);
+        }
+        grep(pattern, fd);
+        close(fd);
+    }
+    exit(0);
+}
\ No newline at end of file
diff --git a/src/user/kill.cc b/src/user/kill.cc
new file mode 100644
index 0000000..18b7f02
--- /dev/null
+++ b/src/user/kill.cc
@@ -0,0 +1,23 @@
+#include "ulib/stdio.h"
+#include "ulib/stdlib.h"
+#include "user/user.h"
+
+int main(int argc, char *argv[])
+{
+    int i;
+
+    if (argc < 2)
+    {
+        printf("Usage: kill pid...\n");
+        exit(1);
+    }
+    for (i = 1; i < argc; i++)
+    {
+        int pid = atoi(argv[i]);
+        if (kill(pid) < 0)
+        {
+            printf("kill: failed to kill %d\n", pid);
+        }
+    }
+    exit(0);
+}
\ No newline at end of file
diff --git a/src/user/ln.cc b/src/user/ln.cc
new file mode 100644
index 0000000..2370fdc
--- /dev/null
+++ b/src/user/ln.cc
@@ -0,0 +1,18 @@
+#include "ulib/stdio.h"
+#include "ulib/stdlib.h"
+#include "user/user.h"
+
+int main(int argc, char *argv[])
+{
+    if (argc != 3)
+    {
+        printf("Usage: ln old new\n");
+        exit(1);
+    }
+    if (link(argv[1], argv[2]) < 0)
+    {
+        printf("link %s %s failed\n", argv[1], argv[2]);
+        exit(1);
+    }
+    exit(0);
+}
\ No newline at end of file
diff --git a/src/user/mv.cc b/src/user/mv.cc
new file mode 100644
index 0000000..2d30f01
--- /dev/null
+++ b/src/user/mv.cc
@@ -0,0 +1,26 @@
+#include "ulib/stdio.h"
+#include "ulib/stdlib.h"
+#include "user/user.h"
+
+int main(int argc, char *argv[])
+{
+    if (argc != 3)
+    {
+        printf("Usage: mv old new\n");
+        exit(1);
+    }
+
+    if (link(argv[1], argv[2]) < 0)
+    {
+        printf("mv: failed to link %s to %s\n", argv[1], argv[2]);
+        exit(1);
+    }
+
+    if (unlink(argv[1]) < 0)
+    {
+        printf("mv: failed to unlink %s\n", argv[1]);
+        exit(1);
+    }
+
+    exit(0);
+}
\ No newline at end of file
diff --git a/src/user/rm.cc b/src/user/rm.cc
new file mode 100644
index 0000000..82b04c5
--- /dev/null
+++ b/src/user/rm.cc
@@ -0,0 +1,24 @@
+#include "ulib/stdio.h"
+#include "ulib/stdlib.h"
+#include "user/user.h"
+
+int main(int argc, char *argv[])
+{
+    int i;
+
+    if (argc < 2)
+    {
+        printf("Usage: rm files...\n");
+        exit(1);
+    }
+
+    for (i = 1; i < argc; i++)
+    {
+        if (unlink(argv[i]) < 0)
+        {
+            printf("rm: %s failed to delete\n", argv[i]);
+            exit(1);
+        }
+    }
+    exit(0);
+}
\ No newline at end of file
diff --git a/src/user/sh.cc b/src/user/sh.cc
index b4122f7..760f29e 100644
--- a/src/user/sh.cc
+++ b/src/user/sh.cc
@@ -67,11 +67,26 @@ struct RedirCommand : public Command
     void run() override
     {
         close(fd);
-        if (open(file, mode) < 0)
+
+        int newfd = open(file, mode);
+
+        if (newfd < 0)
         {
             printf("open %s failed\n", file);
             exit(1);
         }
+
+        if (newfd != fd)
+        {
+
+            if (dup(newfd) != fd)
+            {
+                printf("Redirection failed: could not move fd %d to %d\n", newfd, fd);
+                exit(1);
+            }
+            close(newfd);
+        }
+
         sub_cmd->run();
     }
 };
@@ -348,15 +363,6 @@ int main()
 {
     static char buf[100];
 
-    // int fd;
-    // while ((fd = open("console", O_RDWR)) >= 0)
-    // {
-    //     if (fd >= 3)
-    //     {
-    //         close(fd);
-    //         break;
-    //     }
-    // }
 
     printf(ANSI_GREEN"\n[Lume Shell] Welcome! \n"ANSI_RESET);
     printf(ANSI_YELLOW "[Lume Shell] Start your journey of exploration!"ANSI_RESET);
diff --git a/src/user/touch.cc b/src/user/touch.cc
new file mode 100644
index 0000000..b978f52
--- /dev/null
+++ b/src/user/touch.cc
@@ -0,0 +1,27 @@
+#include "ulib/stdio.h"
+#include "ulib/stdlib.h"
+#include "user/user.h"
+#include "common/fcntl.h"
+
+int main(int argc, char *argv[])
+{
+    int i, fd;
+
+    if (argc < 2)
+    {
+        printf("Usage: touch files...\n");
+        exit(1);
+    }
+
+    for (i = 1; i < argc; i++)
+    {
+        fd = open(argv[i], O_CREATE | O_RDWR);
+        if (fd < 0)
+        {
+            printf("touch: cannot touch %s\n", argv[i]);
+            exit(1);
+        }
+        close(fd);
+    }
+    exit(0);
+}
\ No newline at end of file
diff --git a/src/user/wc.cc b/src/user/wc.cc
new file mode 100644
index 0000000..654aac2
--- /dev/null
+++ b/src/user/wc.cc
@@ -0,0 +1,56 @@
+#include "ulib/stdio.h"
+#include "ulib/stdlib.h"
+#include "ulib/string.h"
+#include "user/user.h"
+#include "common/fcntl.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;
+            }
+        }
+    }
+    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], O_RDONLY)) < 0)
+        {
+            printf("wc: cannot open %s\n", argv[i]);
+            exit(1);
+        }
+        wc(fd, argv[i]);
+        close(fd);
+    }
+    exit(0);
+}
\ No newline at end of file