we are now prepared for piping with _pipe and _dup2

3 files changed, 28 insertions, 4 deletions

diff --git a/userspace/cat.c b/userspace/cat.c
index d0b018b..94cbdaa 100644
--- a/userspace/cat.c
+++ b/userspace/cat.c
@@ -1,7 +1,10 @@
 #include <stdio.h>
+#include <stdlib.h>
 
 int main(int argc, char **argv)
 {   
+    printf("hmm\n");
+    printf("pwd=%s\n",getenv("PWD"));
     FILE *f;
     if(argc>1){
 	char buf[256];
diff --git a/userspace/grep.c b/userspace/grep.c
new file mode 100644
index 0000000..c37392f
--- /dev/null
+++ b/userspace/grep.c
@@ -0,0 +1,17 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(int argc, char **argv)
+{
+    while(1)
+    {
+	char buf[256];
+	int l=fread(buf,1,255,stdin);
+	if(l==0)break;
+	buf[l]=0;
+	printf("grep: %s",buf);
+
+    }
+
+    return EXIT_SUCCESS;
+}
diff --git a/userspace/piper.c b/userspace/piper.c
index e433a5c..f45248e 100644
--- a/userspace/piper.c
+++ b/userspace/piper.c
@@ -1,5 +1,6 @@
 #include <stdio.h>
 #include "newcalls.h"
+
 int main()
 {
     int fds[2];
@@ -15,7 +16,11 @@ int main()
 	{
 	    char buf[256];
 	    int len=fread(buf,1,255,fds[0]);
-	    printf("%s",buf);
+	    //int len=_read(fds[0],buf,255);
+	    buf[len]=0;
+	    printf("-\n");
+	    printf("%s\n",buf);
+	    printf("-\n");
 	}
 
     }
@@ -23,9 +28,8 @@ int main()
     {
 
 	// write to our pipe
-	fwrite("Hello\n",1,6,fds[1]);
-	fwrite("Bello\n",1,6,fds[1]);
-	fwrite("Gello\n",1,6,fds[1]);
+        _write(fds[1],"Hello\n",fds[1]);
+        _write(fds[1],"Bello\n",fds[1]);
 
 	// hang forever
 	while(1);