i/o redirection in sh

better parsing of sh commands (copied from jos sh)
cat: read from 1 if no args
sbrk system call, but untested
getpid system call
moved locks in keyboard intr, but why do we get intr w. null characters from keyboard?

1 files changed, 29 insertions, 0 deletions

diff --git a/syscall.c b/syscall.c
index 80d5d8e..39c6821 100644
--- a/syscall.c
+++ b/syscall.c
@@ -140,6 +140,7 @@ sys_write(void)
     return -1;
   if(addr + n > p->sz)
     return -1;
+
   ret = fd_write(p->fds[fd], p->mem + addr, n);
   return ret;
 }
@@ -421,6 +422,7 @@ sys_dup(void)
     fd_close(fd1);
     return -1;
   }
+  cp->fds[ufd1] = fd1;
   fd1->type = cp->fds[fd]->type;
   fd1->readable = cp->fds[fd]->readable;
   fd1->writeable = cp->fds[fd]->writeable;
@@ -450,6 +452,27 @@ sys_link(void)
 }
 
 int
+sys_getpid(void)
+{
+  struct proc *cp = curproc[cpu()];
+  return cp->pid;
+}
+
+
+int
+sys_sbrk(void)
+{
+  int r, n;
+  struct proc *cp = curproc[cpu()];
+
+  if(fetcharg(0, &n) < 0)
+    return -1;
+  r = growproc(n);
+  setupsegs(cp);  
+  return r;
+}
+
+int
 sys_exec(void)
 {
   struct proc *cp = curproc[cpu()];
@@ -638,6 +661,12 @@ syscall(void)
   case SYS_dup:
     ret = sys_dup();
     break;
+  case SYS_getpid:
+    ret = sys_getpid();
+    break;
+  case SYS_sbrk:
+    ret = sys_sbrk();
+    break;
   default:
     cprintf("unknown sys call %d\n", num);
     // XXX fault