here it is v0.01!

Rakefile

@@ -131,10 +131,12 @@ end
 
 # ----------------------------------------------------------------------
 
-usr_cfiles = Dir['usr/test_*.c'] + %w{
+usr_cfiles = Dir['usr/test/*.c'] + %w{
   usr/init.c
   usr/hello.c
   usr/sh.c
+  usr/ls.c
+  usr/cat.c
 }
 usr_ofiles = usr_cfiles.map{|fn| 'bin/usr/'+File.basename(fn).ext('o') }
 usr_efiles = usr_cfiles.map{|fn| 'bin/usr/'+File.basename(fn).ext('') }

root/home/about2.txt

@@ -0,0 +1,5 @@
+When life leaves us blind
+Love keeps us kind
+When Life leaves us blind
+Love keeps us kind
+

root/home/about3.txt

@@ -0,0 +1 @@
+god saves us everyone when we are burning in the fire of a thousand suns.

src/fs/link.c

@@ -8,6 +8,7 @@
 //
 #include <super.h>
 #include <inode.h>
+#include <dirent.h>
 #include <file.h>
 #include <stat.h>
 

src/fs/namei.c

@@ -8,6 +8,7 @@
 //
 #include <super.h>
 #include <inode.h>
+#include <dirent.h>
 #include <stat.h>
 
 
@@ -124,7 +125,6 @@ struct inode* _namei(char *path, uchar creat, uchar parent, char **name){
     // set it's root directory here.
     if (*path == '/') {
         wip = iget(rootdev, ROOTINO);
-        cu->p_wdir = wip;
     }
     else {
         cdp = cu->p_wdir;
@@ -139,8 +139,8 @@ struct inode* _namei(char *path, uchar creat, uchar parent, char **name){
         }
         // if working inode is root and componet is ".."
         if ((wip->i_num==ROOTINO) && (strncmp(path, "..", 2)==0)) {
-            continue;
         }
+
         // wip must be a directory
         if ((wip->i_mode & S_IFMT)!=S_IFDIR) {
             iput(wip);

src/fs/open.c

@@ -118,6 +118,7 @@ int do_dup(int fd){
     if ((newfd=ufalloc())<0) {
         return -1;
     }
+    fp->f_count++;
     fp->f_ino->i_count++;
     cu->p_ofile[newfd] = fp;
     return newfd;
@@ -134,6 +135,7 @@ int do_dup2(int fd, int newfd){
     }
 
     do_close(newfd);
+    fp->f_count++;
     fp->f_ino->i_count++;
     cu->p_ofile[newfd] = fp;
     return newfd;
@@ -170,5 +172,6 @@ struct file* falloc(int fd){
         }
     }
     syserr(EMFILE);
+    panic("no free file structure\n");
     return NULL;
 }

src/fs/rdwr.c

@@ -37,18 +37,18 @@ int do_read(int fd, char *buf, int cnt){
     }
 
     ip = fp->f_ino;
-    lock_ino(fp->f_ino);
     switch(ip->i_mode & S_IFMT) {
         case S_IFBLK:
             // TODO;
             break;
         case S_IFCHR:
-            dev = ip->i_dev;
+            dev = ip->i_zone[0];
             r = (*cdevsw[MAJOR(dev)].d_read)(dev, buf, cnt);
             break;
         case S_IFDIR:
         case S_IFREG:
         default:
+            lock_ino(fp->f_ino);
             r = readi(ip, buf, fp->f_offset, cnt);
     }
     if (r < 0){

src/inc/dirent.h

@@ -0,0 +1,13 @@
+#ifndef DIRENT_H
+#define DIRENT_H
+
+/* directory entry */
+#define NAMELEN 12
+
+struct dirent {
+    ushort  d_ino;
+    char    d_name[NAMELEN];
+    char    __p[18]; /* a padding. each dirent is aligned with a 32 bytes boundary. */
+};
+
+#endif

src/inc/inode.h

@@ -43,13 +43,4 @@ extern struct inode inode[NINODE];
 
 /* i_mode resides in stat.h */
 
-/* directory entry */
-#define NAMELEN 12
-
-struct dirent {
-    ushort  d_ino;
-    char    d_name[NAMELEN];
-    char    __p[18]; /* a padding. each dirent is aligned with a 32 bytes boundary. */
-};
-
 #endif

src/inc/stat.h

@@ -25,6 +25,13 @@ struct stat {
 #define S_ISGID  0002000
 #define S_ISVTX  0001000
 
+/* predicates */
+#define S_ISREG(m)	(((m) & S_IFMT) == S_IFREG)
+#define S_ISDIR(m)	(((m) & S_IFMT) == S_IFDIR)
+#define S_ISCHR(m)	(((m) & S_IFMT) == S_IFCHR)
+#define S_ISBLK(m)	(((m) & S_IFMT) == S_IFBLK)
+#define S_ISFIFO(m)	(((m) & S_IFMT) == S_IFIFO)
+
 /* access */
 #define RWX_MODES 0000777	/* mode bits for RWX only */
 #define R_BIT    0000004	/* Rwx protection bit */

src/kern/exec.c

@@ -47,12 +47,13 @@
 int do_exec(char *path, char **argv){
     struct inode *ip;
     struct buf *bp;
+    struct sigaction *sa;
     struct ahead *ah;
     struct page *pg;
     struct vm *vm;
     struct vma *vp;
     struct file *fp;
-    uint bn, fd, argc, esp;
+    uint bn, fd, argc, esp, nr;
     char **tmp;
 
     ip = namei(path, 0);
@@ -94,6 +95,14 @@ int do_exec(char *path, char **argv){
             do_close(fd);
         }
     }
+    // clear all sigactions
+    for (nr=0; nr<NSIG; nr++){
+        sa = &cu->p_sigact[nr];
+        sa->sa_handler = SIG_DFL;
+        sa->sa_mask = 0;
+        sa->sa_flags = 0;
+        sa->sa_restorer = NULL;
+    }
     // never forget this:
     brelse(bp);
     iput(ip);

src/kern/exit.c

@@ -31,6 +31,7 @@ int do_exit(int ret){
         if (fp != NULL) {
             do_close(fd);
         }
+        cu->p_ofile[fd] = NULL;
     }
     iput(cu->p_iroot);
     iput(cu->p_wdir);

src/kern/fork.c

@@ -89,6 +89,7 @@ struct proc* kspawn(void (*func)()){
     for (fd=0; fd<NOFILE; fd++){
         fp = cu->p_ofile[fd];
         if (fp != NULL) {
+            fp->f_count++;
             fp->f_ino->i_count++;
         }
         p->p_ofile[fd] = fp;

src/kern/signal.c

@@ -64,14 +64,15 @@ void psig(){
     cu->p_sig &= ~(1<<(n-1));
     sa = &(cu->p_sigact[n-1]);
     // check blocked signal
-    if ((sa->sa_flags & SA_NOMASK)==0) {
-        cu->p_sigmask |= sa->sa_mask;
-    }
     cu->p_cursig = 0;
     if (sa->sa_handler != SIG_DFL) {
         tf = cu->p_trap;
-        // save registers and the old mask 
+        // save registers and the old sa_mask 
         usigsav(&jbuf, tf, cu->p_sigmask);
+        // store the new sa_mask
+        if ((sa->sa_flags & SA_NOMASK)==0) {
+            cu->p_sigmask |= sa->sa_mask;
+        }
         // push to the user stack, with a "shellcode"
         esp = tf->esp;
         usr = upush(&esp, &_usigret, 16);
@@ -91,7 +92,7 @@ void psig(){
         case SIGCHLD:
         case SIGCONT:
             return;
-        // exited on default
+            // exited on default
         case SIGSEGV:
             printk("seg fault.\n");
         case SIGINT:

usr/cat.c

@@ -0,0 +1,32 @@
+#include <param.h>
+#include <file.h>
+#include <stat.h>
+#include <unistd.h>
+#include <dirent.h>
+
+int cat(char *pathp){
+    int fd;
+    char buf[32];
+
+    fd = open(pathp, "r", 0);
+    if (fd < 0) 
+        return -1;
+
+    while(read(fd, buf, 32)>0){
+        printf("%s", buf);
+        memset(buf, 0, 32);
+
+    }
+    write(0, "", 0);
+    close(fd);
+}
+
+int main(int argc, char **argv){
+    int i = 0;
+
+    if (argc>1) {
+        for(i=1; i<argc; i++)
+            cat(argv[i]);
+    }
+    printf("\n");
+}

usr/hello.c

@@ -9,5 +9,8 @@ int main(int argc, char **argv) {
     for(i=0; i<argc; i++){
         printf("%s\n", argv[i]);
     }
+    while(1){
+        printf("hello forever...\n");
+    }
     return 0;
 }

usr/ls.c

@@ -0,0 +1,41 @@
+#include <param.h>
+#include <file.h>
+#include <stat.h>
+#include <unistd.h>
+#include <dirent.h>
+
+int ls(char *pathp){
+    struct stat sbuf;
+    struct dirent dbuf;
+    char pathbuf[1024];
+    int fd, r;
+
+    if (pathp==NULL)
+        strcpy(pathbuf, ".");
+    else 
+        strncpy(pathbuf, pathp, 1024);
+    //
+    fd = open(pathbuf, O_RDONLY, 0);
+    if (fd<0) {
+        return -1;
+    }
+    fstat(fd, &sbuf);
+    if (!S_ISDIR(sbuf.st_mode)){
+        return -1;
+    }
+
+    while((r=read(fd, &dbuf, sizeof(struct dirent)))>0)
+        printf("%s\t", dbuf.d_name);
+}
+
+int main(int argc, char **argv){
+    int i = 0;
+
+    if (argc==1) 
+        ls(NULL);
+    else{
+        for(i=1; i<argc; i++)
+            ls(argv[i]);
+    }
+    printf("\n");
+}

usr/sh.c

@@ -10,6 +10,10 @@ char linebuf[LINEBUFSIZ];
 char* argvbuf[ARGVBUFSIZ];
 char pathbuf[PATHBUFSIZ];
 
+int hwsig(int sign){
+    printf("^C\n");
+}
+
 int lparse(char *lbuf) {
     char *lp, c;
     int argc, i;
@@ -33,23 +37,45 @@ int lparse(char *lbuf) {
 }
 
 int main(int argc, char **argv){
-    int r, i, cnt, ret; 
+    int r,fd, i, cnt, ret; 
+    struct sigaction sa;
 
+    setpgrp();
+    fd = open("/dev/tty0", O_RDWR, 0);
+    close(0);
+    close(1);
+    close(2);
+    dup(fd);
+    dup(fd);
+    dup(fd);
+    fcntl(0, F_SETFD, 0); // turn off FD_CLOEXEC
+    fcntl(1, F_SETFD, 0);
+    fcntl(2, F_SETFD, 0);
+    close(fd);
+    //
+    sa.sa_handler = &hwsig;
+    sigaction(SIGINT, &sa, NULL);
+    //
     while(1) {
         printf("$ ");
         memset(linebuf, 0, LINEBUFSIZ);
         r = read(0, linebuf, 1024);
         linebuf[r] = 0;
         cnt = lparse(linebuf);
         if (cnt > 0) {
-            if (fork()==0) {
-                exec(argvbuf[0], &argvbuf[1]);
-                strcpy(pathbuf, "/bin/");
-                strncat(pathbuf, argvbuf[0], PATHBUFSIZ);
-                exec(pathbuf, &argvbuf[1]);
-                exit(1);
+            if (strncmp(argvbuf[0], "cd", 2)==0) {
+                chdir(argvbuf[1]);
+            }
+            else {
+                if (fork()==0) {
+                    exec(argvbuf[0], &argvbuf[1]);
+                    strcpy(pathbuf, "/bin/");
+                    strncat(pathbuf, argvbuf[0], PATHBUFSIZ);
+                    exec(pathbuf, &argvbuf[1]);
+                    exit(1);
+                }
+                wait(&ret);
             }
-            wait(&ret);
         }
     }
 }

usr/test/test_chdir.c

@@ -0,0 +1,19 @@
+#include <param.h>
+#include <file.h>
+#include <unistd.h>
+
+int a=3;
+
+int main(int argc, char **argv) {
+    int fd;
+
+    printf("open about.txt: %d\n", open("about.txt", O_RDWR, 0));
+    chdir("home");
+    printf("cd home\n");
+    printf("open about.txt: %d\n", open("about.txt", O_RDWR, 0));
+    chdir(".");
+    printf(".\n");
+    printf("open about.txt: %d\n", open("about.txt", O_RDWR, 0));
+    return 0;
+}
+